Merge remote-tracking branch 'remotes/riscv/tags/riscv-qemu-upstream-v8.2' into staging

QEMU RISC-V Emulation Support (RV64GC, RV32GC)

This release renames the SiFive machines to sifive_e and sifive_u
to represent the SiFive Everywhere and SiFive Unleashed platforms.
SiFive has configurable soft-core IP, so it is intended that these
machines will be extended to enable a variety of SiFive IP blocks.
The CPU definition infrastructure has been improved and there are
now vendor CPU modules including the SiFiVe E31, E51, U34 and U54
cores. The emulation accuracy for the E series has been improved
by disabling the MMU for the E series. S mode has been disabled on
cores that only support M mode and U mode. The two Spike machines
that support two privileged ISA versions have been coalesced into
one file. This series has Signed-off-by from the core contributors.

*** Known Issues ***

* Disassembler has some checkpatch warnings for the sake of code brevity
* scripts/qemu-binfmt-conf.sh has checkpatch warnings due to line length
* PMP (Physical Memory Protection) is as-of-yet unused and needs testing

*** Changelog ***

v8.2

* Rebase

v8.1

* Fix missed case of renaming spike_v1.9 to spike_v1.9.1

v8

* Added linux-user/riscv/target_elf.h during rebase
* Make resetvec configurable and clear mpp and mie on reset
* Use SiFive E31, E51, U34 and U54 cores in SiFive machines
* Define SiFive E31, E51, U34 and U54 cores
* Refactor CPU core definition in preparation for vendor cores
* Prevent S or U mode unless S or U extensions are present
* SiFive E Series cores have no MMU
* SiFive E Series cores have U mode
* Make privileged ISA v1.10 implicit in CPU types
* Remove DRAM_BASE and EXT_IO_BASE as they vary by machine
* Correctly handle mtvec and stvec alignment with respect to RVC
* Print more machine mode state in riscv_cpu_dump_state
* Make riscv_isa_string use compact extension order method
* Fix bug introduced in v6 RISCV_CPU_TYPE_NAME macro change
* Parameterize spike v1.9.1 config string
* Coalesce spike_v1.9.1 and spike_v1.10 machines
* Rename sifive_e300 to sifive_e, and sifive_u500 to sifive_u

v7

* Make spike_v1.10 the default machine
* Rename spike_v1.9 to spike_v1.9.1 to match privileged spec version
* Remove empty target/riscv/trace-events file
* Monitor ROM 32-bit reset code needs to be target endian
* Add TARGET_TIOCGPTPEER to linux-user/riscv/termbits.h
* Add -initrd support to the virt board
* Fix naming in spike machine interface header
* Update copyright notice on RISC-V Spike machines
* Update copyright notice on RISC-V HTIF Console device
* Change CPU Core and translator to GPLv2+
* Change RISC-V Disassembler to GPLv2+
* Change SiFive Test Finisher to GPLv2+
* Change SiFive CLINT to GPLv2+
* Change SiFive PRCI to GPLv2+
* Change SiFive PLIC to GPLv2+
* Change RISC-V spike machines to GPLv2+
* Change RISC-V virt machine to GPLv2+
* Change SiFive E300 machine to GPLv2+
* Change SiFive U500 machine to GPLv2+
* Change RISC-V Hart Array to GPLv2+
* Change RISC-V HTIF device to GPLv2+
* Change SiFiveUART device to GPLv2+

v6

* Drop IEEE 754-201x minimumNumber/maximumNumber for fmin/fmax
* Remove some unnecessary commented debug statements
* Change RISCV_CPU_TYPE_NAME to use riscv-cpu suffix
* Define all CPU variants for linux-user
* qemu_log calls require trailing \n
* Replace PLIC printfs with qemu_log
* Tear out unused HTIF code and eliminate shouting debug messages
* Fix illegal instruction when sfence.vma is passed (rs2) arguments
* Make updates to PTE accessed and dirty bits atomic
* Only require atomic PTE updates on MTTCG enabled guests
* Page fault if accessed or dirty bits can't be updated
* Fix get_physical_address PTE reads and writes on riscv32
* Remove erroneous comments from the PLIC
* Default enable MTTCG
* Make WFI less conservative
* Unify local interrupt handling
* Expunge HTIF interrupts
* Always access mstatus.mip under a lock
* Don't implement rdtime/rdtimeh in system mode (bbl emulates them)
* Implement insreth/cycleh for rv32 and always enable user-mode counters
* Add GDB stub support for reading and writing CSRs
* Rename ENABLE_CHARDEV #ifdef from HTIF code
* Replace bad HTIF ELF code with load_elf symbol callback
* Convert chained if else fault handlers to switch statements
* Use RISCV exception codes for linux-user page faults

v5

* Implement NaN-boxing for flw, set high order bits to 1
* Use float_muladd_negate_* flags to floatXX_muladd
* Use IEEE 754-201x minimumNumber/maximumNumber for fmin/fmax
* Fix TARGET_NR_syscalls
* Update linux-user/riscv/syscall_nr.h
* Fix FENCE.I, needs to terminate translation block
* Adjust unusual convention for interruptno >= 0

v4

* Add @riscv: since 2.12 to CpuInfoArch
* Remove misleading little-endian comment from load_kernel
* Rename cpu-model property to cpu-type
* Drop some unnecessary inline function attributes
* Don't allow GDB to set value of x0 register
* Remove unnecessary empty property lists
* Add Test Finisher device to implement poweroff in virt machine
* Implement priv ISA v1.10 trap and sret/mret xPIE/xIE behavior
* Store fflags data in fp_status
* Purge runtime users of helper_raise_exception
* Fix validate_csr
* Tidy gen_jalr
* Tidy immediate shifts
* Add gen_exception_inst_addr_mis
* Add gen_exception_debug
* Add gen_exception_illegal
* Tidy helper_fclass_*
* Split rounding mode setting to a new function
* Enforce MSTATUS_FS via TB flags
* Implement acquire/release barrier semantics
* Use atomic operations as required
* Fix FENCE and FENCE_I
* Remove commented code from spike machines
* PAGE_WRITE permissions can be set on loads if page is already dirty
* The result of format conversion on an NaN must be a quiet NaN
* Add missing process_queued_cpu_work to riscv linux-user
* Remove float(32|64)_classify from cpu.h
* Removed nonsensical unions aliasing the same type
* Use uintN_t instead of uintN_fast_t in fpu_helper.c
* Use macros for FPU exception values in softfloat_flags_to_riscv
* Move code to set round mode into set_fp_round_mode function
* Convert set_fp_exceptions from a macro to an inline function
* Convert round mode helper into an inline function
* Make fpu_helper ieee_rm array static const
* Include cpu_mmu_index in cpu_get_tb_cpu_state flags
* Eliminate MPRV influence on mmu_index
* Remove unrecoverable do_unassigned_access function
* Only update PTE accessed and dirty bits if necessary
* Remove unnecessary tlb_flush in set_mode as mode is in mmu_idx
* Remove buggy support for misa writes. misa writes are optional
  and are not implemented in any known hardware
* Always set PTE read or execute permissions during page walk
* Reorder helper function declarations to match order in helper.c
* Remove redundant variable declaration in get_physical_address
* Remove duplicated code from get_physical_address
* Use mmu_idx instead of mem_idx in riscv_cpu_get_phys_page_debug

v3

* Fix indentation in PMP and HTIF debug macros
* Fix disassembler checkpatch open brace '{' on next line errors
* Fix trailing statements on next line in decode_inst_decompress
* NOTE: the other checkpatch issues have been reviewed previously

v2

* Remove redundant NULL terminators from disassembler register arrays
* Change disassembler register name arrays to const
* Refine disassembler internal function names
* Update dates in disassembler copyright message
* Remove #ifdef CONFIG_USER_ONLY version of cpu_has_work
* Use ULL suffix on 64-bit constants
* Move riscv_cpu_mmu_index from cpu.h to helper.c
* Move riscv_cpu_hw_interrupts_pending from cpu.h to helper.c
* Remove redundant TARGET_HAS_ICE from cpu.h
* Use qemu_irq instead of void* for irq definition in cpu.h
* Remove duplicate typedef from struct CPURISCVState
* Remove redundant g_strdup from cpu_register
* Remove redundant tlb_flush from riscv_cpu_reset
* Remove redundant mode calculation from get_physical_address
* Remove redundant debug mode printf and dcsr comment
* Remove redundant clearing of MSB for bare physical addresses
* Use g_assert_not_reached for invalid mode in get_physical_address
* Use g_assert_not_reached for unreachable checks in get_physical_address
* Use g_assert_not_reached for unreachable type in raise_mmu_exception
* Return exception instead of aborting for misaligned fetches
* Move exception defines from cpu.h to cpu_bits.h
* Remove redundant breakpoint control definitions from cpu_bits.h
* Implement riscv_cpu_unassigned_access exception handling
* Log and raise exceptions for unimplemented CSRs
* Match Spike HTIF exit behavior - don’t print TEST-PASSED
* Make frm,fflags,fcsr writes trap when mstatus.FS is clear
* Use g_assert_not_reached for unreachable invalid mode
* Make hret,uret,dret generate illegal instructions
* Move riscv_cpu_dump_state and int/fpr regnames to cpu.c
* Lift interrupt flag and mask into constants in cpu_bits.h
* Change trap debugging to use qemu_log_mask LOG_TRACE
* Change CSR debugging to use qemu_log_mask LOG_TRACE
* Change PMP debugging to use qemu_log_mask LOG_TRACE
* Remove commented code from pmp.c
* Change CpuInfoRISCV qapi schema docs to Since 2.12
* Change RV feature macro to use target_ulong cast
* Remove riscv_feature and instead use misa extension flags
* Make riscv_flush_icache_syscall a no-op
* Undo checkpatch whitespace fixes in unrelated linux-user code
* Remove redudant constants and tidy up cpu_bits.h
* Make helper_fence_i a no-op
* Move include "exec/cpu-all" to end of cpu.h
* Rename set_privilege to riscv_set_mode
* Move redundant forward declaration for cpu_riscv_translate_address
* Remove TCGV_UNUSED from riscv_translate_init
* Add comment to pmp.c stating the code is untested and currently unused
* Use ctz to simplify decoding of PMP NAPOT address ranges
* Change pmp_is_in_range to use than equal for end addresses
* Fix off by one error in pmp_update_rule
* Rearrange PMP_DEBUG so that formatting is compile-time checked
* Rearrange trap debugging so that formatting is compile-time checked
* Rearrange PLIC debugging so that formatting is compile-time checked
* Use qemu_log/qemu_log_mask for HTIF logging and debugging
* Move exception and interrupt names into cpu.c
* Add Palmer Dabbelt as a RISC-V Maintainer
* Rebase against current qemu master branch

v1

* initial version based on forward port from riscv-qemu repository

*** Background ***

"RISC-V is an open, free ISA enabling a new era of processor innovation
through open standard collaboration. Born in academia and research,
RISC-V ISA delivers a new level of free, extensible software and
hardware freedom on architecture, paving the way for the next 50 years
of computing design and innovation."

The QEMU RISC-V port has been developed and maintained out-of-tree for
several years by Sagar Karandikar and Bastian Koppelmann. The RISC-V
Privileged specification has evolved substantially over this period but
has recently been solidifying. The RISC-V Base ISA has been frozon for
some time and the Privileged ISA, GCC toolchain and Linux ABI are now
quite stable. I have recently joined Sagar and Bastian as a RISC-V QEMU
Maintainer and hope to support upstreaming the port.

There are multiple vendors taping out, preparing to ship, or shipping
silicon that implements the RISC-V Privileged ISA Version 1.10. There
are also several RISC-V Soft-IP cores implementing Privileged ISA
Version 1.10 that run on FPGA such as SiFive's Freedom U500 Platform
and the U54‑MC RISC-V Core IP, among many more implementations from a
variety of vendors. See https://riscv.org/ for more details.

RISC-V support was upstreamed in binutils 2.28 and GCC 7.1 in the first
half of 2016. RISC-V support is now available in LLVM top-of-tree and
the RISC-V Linux port was accepted into Linux 4.15-rc1 late last year
and is available in the Linux 4.15 release. GLIBC 2.27 added support
for the RISC-V ISA running on Linux (requires at least binutils-2.30,
gcc-7.3.0, and linux-4.15). We believe it is timely to submit the
RISC-V QEMU port for upstream review with the goal of incorporating
RISC-V support into the upcoming QEMU 2.12 release.

The RISC-V QEMU port is still under active development, mostly with
respect to device emulation, the addition of Hypervisor support as
specified in the RISC-V Draft Privileged ISA Version 1.11, and Vector
support once the first draft is finalized later this year. We believe
now is the appropriate time for RISC-V QEMU development to be carried
out in the main QEMU repository as the code will benefit from more
rigorous review. The RISC-V QEMU port currently supports all the ISA
extensions that have been finalized and frozen in the Base ISA.

Blog post about recent additions to RISC-V QEMU: https://goo.gl/fJ4zgk

The RISC-V QEMU wiki: https://github.com/riscv/riscv-qemu/wiki

Instructions for building a busybox+dropbear root image, BBL (Berkeley
Boot Loader) and linux kernel image for use with the RISC-V QEMU
'virt' machine: https://github.com/michaeljclark/busybear-linux

*** Overview ***

The RISC-V QEMU port implements the following specifications:

* RISC-V Instruction Set Manual Volume I: User-Level ISA Version 2.2
* RISC-V Instruction Set Manual Volume II: Privileged ISA Version 1.9.1
* RISC-V Instruction Set Manual Volume II: Privileged ISA Version 1.10

The RISC-V QEMU port supports the following instruction set extensions:

* RV32GC with Supervisor-mode and User-mode (RV32IMAFDCSU)
* RV64GC with Supervisor-mode and User-mode (RV64IMAFDCSU)

The RISC-V QEMU port adds the following targets to QEMU:

* riscv32-softmmu
* riscv64-softmmu
* riscv32-linux-user
* riscv64-linux-user

The RISC-V QEMU port supports the following hardware:

* HTIF Console (Host Target Interface)
* SiFive CLINT (Core Local Interruptor) for Timer interrupts and IPIs
* SiFive PLIC (Platform Level Interrupt Controller)
* SiFive Test (Test Finisher) for exiting simulation
* SiFive UART, PRCI, AON, PWM, QSPI support is partially implemented
* VirtIO MMIO (GPEX PCI support will be added in a future patch)
* Generic 16550A UART emulation using 'hw/char/serial.c'
* MTTCG and SMP support (PLIC and CLINT) on the 'virt' machine

The RISC-V QEMU full system emulator supports 5 machines:

* 'spike_v1.9.1', CLINT, PLIC, HTIF console, config-string, Priv v1.9.1
* 'spike_v1.10', CLINT, PLIC, HTIF console, device-tree, Priv v1.10
* 'sifive_e', CLINT, PLIC, SiFive UART, HiFive1 compat, Priv v1.10
* 'sifive_u', CLINT, PLIC, SiFive UART, device-tree, Priv v1.10
* 'virt', CLINT, PLIC, 16550A UART, VirtIO, device-tree, Priv v1.10

This is a list of RISC-V QEMU Port Contributors:

* Alex Suykov
* Andreas Schwab
* Antony Pavlov
* Bastian Koppelmann
* Bruce Hoult
* Chih-Min Chao
* Daire McNamara
* Darius Rad
* David Abdurachmanov
* Hesham Almatary
* Ivan Griffin
* Jim Wilson
* Kito Cheng
* Michael Clark
* Palmer Dabbelt
* Richard Henderson
* Sagar Karandikar
* Shea Levy
* Stefan O'Rear

Notes:

* contributor email addresses available off-list on request.
* checkpatch has been run on all 23 patches.
* checkpatch exceptions are noted in patches that have errors.
* passes "make check" on full build for all targets
* tested riscv-linux-4.6.2 on 'spike_v1.9.1' machine
* tested riscv-linux-4.15 on 'spike_v1.10' and 'virt' machines
* tested SiFive HiFive1 binaries in 'sifive_e' machine
* tested RV64 on 32-bit i386

This patch series includes the following patches:

# gpg: Signature made Thu 08 Mar 2018 19:40:20 GMT
# gpg:                using DSA key 6BF1D7B357EF3E4F
# gpg: Good signature from "Michael Clark <michaeljclark@mac.com>"
# gpg:                 aka "Michael Clark <mjc@sifive.com>"
# gpg:                 aka "Michael Clark <michael@metaparadigm.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 7C99 930E B17C D8BA 073D  5EFA 6BF1 D7B3 57EF 3E4F

* remotes/riscv/tags/riscv-qemu-upstream-v8.2: (23 commits)
  RISC-V Build Infrastructure
  SiFive Freedom U Series RISC-V Machine
  SiFive Freedom E Series RISC-V Machine
  SiFive RISC-V PRCI Block
  SiFive RISC-V UART Device
  RISC-V VirtIO Machine
  SiFive RISC-V Test Finisher
  RISC-V Spike Machines
  SiFive RISC-V PLIC Block
  SiFive RISC-V CLINT Block
  RISC-V HART Array
  RISC-V HTIF Console
  Add symbol table callback interface to load_elf
  RISC-V Linux User Emulation
  RISC-V Physical Memory Protection
  RISC-V TCG Code Generation
  RISC-V GDB Stub
  RISC-V FPU Support
  RISC-V CPU Helpers
  RISC-V Disassembler
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

13 files changed, 2860 insertions, 2 deletions

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 76b244c508..06bdbca537 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -450,6 +450,20 @@ int load_elf_ram(const char *filename,
                  int clear_lsb, int data_swab, AddressSpace *as,
                  bool load_rom)
 {
+    return load_elf_ram_sym(filename, translate_fn, translate_opaque,
+                            pentry, lowaddr, highaddr, big_endian,
+                            elf_machine, clear_lsb, data_swab, as,
+                            load_rom, NULL);
+}
+
+/* return < 0 if error, otherwise the number of bytes loaded in memory */
+int load_elf_ram_sym(const char *filename,
+                     uint64_t (*translate_fn)(void *, uint64_t),
+                     void *translate_opaque, uint64_t *pentry,
+                     uint64_t *lowaddr, uint64_t *highaddr, int big_endian,
+                     int elf_machine, int clear_lsb, int data_swab,
+                     AddressSpace *as, bool load_rom, symbol_fn_t sym_cb)
+{
     int fd, data_order, target_data_order, must_swab, ret = ELF_LOAD_FAILED;
     uint8_t e_ident[EI_NIDENT];
 
@@ -488,11 +502,11 @@ int load_elf_ram(const char *filename,
     if (e_ident[EI_CLASS] == ELFCLASS64) {
         ret = load_elf64(filename, fd, translate_fn, translate_opaque, must_swab,
                          pentry, lowaddr, highaddr, elf_machine, clear_lsb,
-                         data_swab, as, load_rom);
+                         data_swab, as, load_rom, sym_cb);
     } else {
         ret = load_elf32(filename, fd, translate_fn, translate_opaque, must_swab,
                          pentry, lowaddr, highaddr, elf_machine, clear_lsb,
-                         data_swab, as, load_rom);
+                         data_swab, as, load_rom, sym_cb);
     }
 
  fail:
diff --git a/hw/riscv/Makefile.objs b/hw/riscv/Makefile.objs
new file mode 100644
index 0000000000..1dde01d39d
--- /dev/null
+++ b/hw/riscv/Makefile.objs
@@ -0,0 +1,11 @@
+obj-y += riscv_htif.o
+obj-y += riscv_hart.o
+obj-y += sifive_e.o
+obj-y += sifive_clint.o
+obj-y += sifive_prci.o
+obj-y += sifive_plic.o
+obj-y += sifive_test.o
+obj-y += sifive_u.o
+obj-y += sifive_uart.o
+obj-y += spike.o
+obj-y += virt.o
diff --git a/hw/riscv/riscv_hart.c b/hw/riscv/riscv_hart.c
new file mode 100644
index 0000000000..14e3c186fe
--- /dev/null
+++ b/hw/riscv/riscv_hart.c
@@ -0,0 +1,89 @@
+/*
+ * QEMU RISCV Hart Array
+ *
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * Holds the state of a heterogenous array of RISC-V harts
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/sysbus.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/riscv_hart.h"
+
+static Property riscv_harts_props[] = {
+    DEFINE_PROP_UINT32("num-harts", RISCVHartArrayState, num_harts, 1),
+    DEFINE_PROP_STRING("cpu-type", RISCVHartArrayState, cpu_type),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void riscv_harts_cpu_reset(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    cpu_reset(CPU(cpu));
+}
+
+static void riscv_harts_realize(DeviceState *dev, Error **errp)
+{
+    RISCVHartArrayState *s = RISCV_HART_ARRAY(dev);
+    Error *err = NULL;
+    int n;
+
+    s->harts = g_new0(RISCVCPU, s->num_harts);
+
+    for (n = 0; n < s->num_harts; n++) {
+
+        object_initialize(&s->harts[n], sizeof(RISCVCPU), s->cpu_type);
+        s->harts[n].env.mhartid = n;
+        object_property_add_child(OBJECT(s), "harts[*]", OBJECT(&s->harts[n]),
+                                  &error_abort);
+        qemu_register_reset(riscv_harts_cpu_reset, &s->harts[n]);
+        object_property_set_bool(OBJECT(&s->harts[n]), true,
+                                 "realized", &err);
+        if (err) {
+            error_propagate(errp, err);
+            return;
+        }
+    }
+}
+
+static void riscv_harts_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->props = riscv_harts_props;
+    dc->realize = riscv_harts_realize;
+}
+
+static void riscv_harts_init(Object *obj)
+{
+    /* RISCVHartArrayState *s = SIFIVE_COREPLEX(obj); */
+}
+
+static const TypeInfo riscv_harts_info = {
+    .name          = TYPE_RISCV_HART_ARRAY,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(RISCVHartArrayState),
+    .instance_init = riscv_harts_init,
+    .class_init    = riscv_harts_class_init,
+};
+
+static void riscv_harts_register_types(void)
+{
+    type_register_static(&riscv_harts_info);
+}
+
+type_init(riscv_harts_register_types)
diff --git a/hw/riscv/riscv_htif.c b/hw/riscv/riscv_htif.c
new file mode 100644
index 0000000000..3e17f30251
--- /dev/null
+++ b/hw/riscv/riscv_htif.c
@@ -0,0 +1,258 @@
+/*
+ * QEMU RISC-V Host Target Interface (HTIF) Emulation
+ *
+ * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
+ * Copyright (c) 2017-2018 SiFive, Inc.
+ *
+ * This provides HTIF device emulation for QEMU. At the moment this allows
+ * for identical copies of bbl/linux to run on both spike and QEMU.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/log.h"
+#include "hw/sysbus.h"
+#include "hw/char/serial.h"
+#include "chardev/char.h"
+#include "chardev/char-fe.h"
+#include "hw/riscv/riscv_htif.h"
+#include "qemu/timer.h"
+#include "exec/address-spaces.h"
+#include "qemu/error-report.h"
+
+#define RISCV_DEBUG_HTIF 0
+#define HTIF_DEBUG(fmt, ...)                                                   \
+    do {                                                                       \
+        if (RISCV_DEBUG_HTIF) {                                                \
+            qemu_log_mask(LOG_TRACE, "%s: " fmt "\n", __func__, ##__VA_ARGS__);\
+        }                                                                      \
+    } while (0)
+
+static uint64_t fromhost_addr, tohost_addr;
+
+void htif_symbol_callback(const char *st_name, int st_info, uint64_t st_value,
+    uint64_t st_size)
+{
+    if (strcmp("fromhost", st_name) == 0) {
+        fromhost_addr = st_value;
+        if (st_size != 8) {
+            error_report("HTIF fromhost must be 8 bytes");
+            exit(1);
+        }
+    } else if (strcmp("tohost", st_name) == 0) {
+        tohost_addr = st_value;
+        if (st_size != 8) {
+            error_report("HTIF tohost must be 8 bytes");
+            exit(1);
+        }
+    }
+}
+
+/*
+ * Called by the char dev to see if HTIF is ready to accept input.
+ */
+static int htif_can_recv(void *opaque)
+{
+    return 1;
+}
+
+/*
+ * Called by the char dev to supply input to HTIF console.
+ * We assume that we will receive one character at a time.
+ */
+static void htif_recv(void *opaque, const uint8_t *buf, int size)
+{
+    HTIFState *htifstate = opaque;
+
+    if (size != 1) {
+        return;
+    }
+
+    /* TODO - we need to check whether mfromhost is zero which indicates
+              the device is ready to receive. The current implementation
+              will drop characters */
+
+    uint64_t val_written = htifstate->pending_read;
+    uint64_t resp = 0x100 | *buf;
+
+    htifstate->env->mfromhost = (val_written >> 48 << 48) | (resp << 16 >> 16);
+}
+
+/*
+ * Called by the char dev to supply special events to the HTIF console.
+ * Not used for HTIF.
+ */
+static void htif_event(void *opaque, int event)
+{
+
+}
+
+static int htif_be_change(void *opaque)
+{
+    HTIFState *s = opaque;
+
+    qemu_chr_fe_set_handlers(&s->chr, htif_can_recv, htif_recv, htif_event,
+        htif_be_change, s, NULL, true);
+
+    return 0;
+}
+
+static void htif_handle_tohost_write(HTIFState *htifstate, uint64_t val_written)
+{
+    uint8_t device = val_written >> 56;
+    uint8_t cmd = val_written >> 48;
+    uint64_t payload = val_written & 0xFFFFFFFFFFFFULL;
+    int resp = 0;
+
+    HTIF_DEBUG("mtohost write: device: %d cmd: %d what: %02" PRIx64
+        " -payload: %016" PRIx64 "\n", device, cmd, payload & 0xFF, payload);
+
+    /*
+     * Currently, there is a fixed mapping of devices:
+     * 0: riscv-tests Pass/Fail Reporting Only (no syscall proxy)
+     * 1: Console
+     */
+    if (unlikely(device == 0x0)) {
+        /* frontend syscall handler, shutdown and exit code support */
+        if (cmd == 0x0) {
+            if (payload & 0x1) {
+                /* exit code */
+                int exit_code = payload >> 1;
+                exit(exit_code);
+            } else {
+                qemu_log_mask(LOG_UNIMP, "pk syscall proxy not supported\n");
+            }
+        } else {
+            qemu_log("HTIF device %d: unknown command\n", device);
+        }
+    } else if (likely(device == 0x1)) {
+        /* HTIF Console */
+        if (cmd == 0x0) {
+            /* this should be a queue, but not yet implemented as such */
+            htifstate->pending_read = val_written;
+            htifstate->env->mtohost = 0; /* clear to indicate we read */
+            return;
+        } else if (cmd == 0x1) {
+            qemu_chr_fe_write(&htifstate->chr, (uint8_t *)&payload, 1);
+            resp = 0x100 | (uint8_t)payload;
+        } else {
+            qemu_log("HTIF device %d: unknown command\n", device);
+        }
+    } else {
+        qemu_log("HTIF unknown device or command\n");
+        HTIF_DEBUG("device: %d cmd: %d what: %02" PRIx64
+            " payload: %016" PRIx64, device, cmd, payload & 0xFF, payload);
+    }
+    /*
+     * - latest bbl does not set fromhost to 0 if there is a value in tohost
+     * - with this code enabled, qemu hangs waiting for fromhost to go to 0
+     * - with this code disabled, qemu works with bbl priv v1.9.1 and v1.10
+     * - HTIF needs protocol documentation and a more complete state machine
+
+        while (!htifstate->fromhost_inprogress &&
+            htifstate->env->mfromhost != 0x0) {
+        }
+    */
+    htifstate->env->mfromhost = (val_written >> 48 << 48) | (resp << 16 >> 16);
+    htifstate->env->mtohost = 0; /* clear to indicate we read */
+}
+
+#define TOHOST_OFFSET1 (htifstate->tohost_offset)
+#define TOHOST_OFFSET2 (htifstate->tohost_offset + 4)
+#define FROMHOST_OFFSET1 (htifstate->fromhost_offset)
+#define FROMHOST_OFFSET2 (htifstate->fromhost_offset + 4)
+
+/* CPU wants to read an HTIF register */
+static uint64_t htif_mm_read(void *opaque, hwaddr addr, unsigned size)
+{
+    HTIFState *htifstate = opaque;
+    if (addr == TOHOST_OFFSET1) {
+        return htifstate->env->mtohost & 0xFFFFFFFF;
+    } else if (addr == TOHOST_OFFSET2) {
+        return (htifstate->env->mtohost >> 32) & 0xFFFFFFFF;
+    } else if (addr == FROMHOST_OFFSET1) {
+        return htifstate->env->mfromhost & 0xFFFFFFFF;
+    } else if (addr == FROMHOST_OFFSET2) {
+        return (htifstate->env->mfromhost >> 32) & 0xFFFFFFFF;
+    } else {
+        qemu_log("Invalid htif read: address %016" PRIx64 "\n",
+            (uint64_t)addr);
+        return 0;
+    }
+}
+
+/* CPU wrote to an HTIF register */
+static void htif_mm_write(void *opaque, hwaddr addr,
+                            uint64_t value, unsigned size)
+{
+    HTIFState *htifstate = opaque;
+    if (addr == TOHOST_OFFSET1) {
+        if (htifstate->env->mtohost == 0x0) {
+            htifstate->allow_tohost = 1;
+            htifstate->env->mtohost = value & 0xFFFFFFFF;
+        } else {
+            htifstate->allow_tohost = 0;
+        }
+    } else if (addr == TOHOST_OFFSET2) {
+        if (htifstate->allow_tohost) {
+            htifstate->env->mtohost |= value << 32;
+            htif_handle_tohost_write(htifstate, htifstate->env->mtohost);
+        }
+    } else if (addr == FROMHOST_OFFSET1) {
+        htifstate->fromhost_inprogress = 1;
+        htifstate->env->mfromhost = value & 0xFFFFFFFF;
+    } else if (addr == FROMHOST_OFFSET2) {
+        htifstate->env->mfromhost |= value << 32;
+        htifstate->fromhost_inprogress = 0;
+    } else {
+        qemu_log("Invalid htif write: address %016" PRIx64 "\n",
+            (uint64_t)addr);
+    }
+}
+
+static const MemoryRegionOps htif_mm_ops = {
+    .read = htif_mm_read,
+    .write = htif_mm_write,
+};
+
+HTIFState *htif_mm_init(MemoryRegion *address_space, MemoryRegion *main_mem,
+    CPURISCVState *env, Chardev *chr)
+{
+    uint64_t base = MIN(tohost_addr, fromhost_addr);
+    uint64_t size = MAX(tohost_addr + 8, fromhost_addr + 8) - base;
+    uint64_t tohost_offset = tohost_addr - base;
+    uint64_t fromhost_offset = fromhost_addr - base;
+
+    HTIFState *s = g_malloc0(sizeof(HTIFState));
+    s->address_space = address_space;
+    s->main_mem = main_mem;
+    s->main_mem_ram_ptr = memory_region_get_ram_ptr(main_mem);
+    s->env = env;
+    s->tohost_offset = tohost_offset;
+    s->fromhost_offset = fromhost_offset;
+    s->pending_read = 0;
+    s->allow_tohost = 0;
+    s->fromhost_inprogress = 0;
+    qemu_chr_fe_init(&s->chr, chr, &error_abort);
+    qemu_chr_fe_set_handlers(&s->chr, htif_can_recv, htif_recv, htif_event,
+        htif_be_change, s, NULL, true);
+    if (base) {
+        memory_region_init_io(&s->mmio, NULL, &htif_mm_ops, s,
+                            TYPE_HTIF_UART, size);
+        memory_region_add_subregion(address_space, base, &s->mmio);
+    }
+
+    return s;
+}
diff --git a/hw/riscv/sifive_clint.c b/hw/riscv/sifive_clint.c
new file mode 100644
index 0000000000..4893453b70
--- /dev/null
+++ b/hw/riscv/sifive_clint.c
@@ -0,0 +1,254 @@
+/*
+ * SiFive CLINT (Core Local Interruptor)
+ *
+ * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * This provides real-time clock, timer and interprocessor interrupts.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "hw/sysbus.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/sifive_clint.h"
+#include "qemu/timer.h"
+
+/* See: riscv-pk/machine/sbi_entry.S and arch/riscv/kernel/time.c */
+#define TIMER_FREQ (10 * 1000 * 1000)
+
+static uint64_t cpu_riscv_read_rtc(void)
+{
+    return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), TIMER_FREQ,
+                    NANOSECONDS_PER_SECOND);
+}
+
+/*
+ * Called when timecmp is written to update the QEMU timer or immediately
+ * trigger timer interrupt if mtimecmp <= current timer value.
+ */
+static void sifive_clint_write_timecmp(RISCVCPU *cpu, uint64_t value)
+{
+    uint64_t next;
+    uint64_t diff;
+
+    uint64_t rtc_r = cpu_riscv_read_rtc();
+
+    cpu->env.timecmp = value;
+    if (cpu->env.timecmp <= rtc_r) {
+        /* if we're setting an MTIMECMP value in the "past",
+           immediately raise the timer interrupt */
+        riscv_set_local_interrupt(cpu, MIP_MTIP, 1);
+        return;
+    }
+
+    /* otherwise, set up the future timer interrupt */
+    riscv_set_local_interrupt(cpu, MIP_MTIP, 0);
+    diff = cpu->env.timecmp - rtc_r;
+    /* back to ns (note args switched in muldiv64) */
+    next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
+        muldiv64(diff, NANOSECONDS_PER_SECOND, TIMER_FREQ);
+    timer_mod(cpu->env.timer, next);
+}
+
+/*
+ * Callback used when the timer set using timer_mod expires.
+ * Should raise the timer interrupt line
+ */
+static void sifive_clint_timer_cb(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    riscv_set_local_interrupt(cpu, MIP_MTIP, 1);
+}
+
+/* CPU wants to read rtc or timecmp register */
+static uint64_t sifive_clint_read(void *opaque, hwaddr addr, unsigned size)
+{
+    SiFiveCLINTState *clint = opaque;
+    if (addr >= clint->sip_base &&
+        addr < clint->sip_base + (clint->num_harts << 2)) {
+        size_t hartid = (addr - clint->sip_base) >> 2;
+        CPUState *cpu = qemu_get_cpu(hartid);
+        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
+        if (!env) {
+            error_report("clint: invalid timecmp hartid: %zu", hartid);
+        } else if ((addr & 0x3) == 0) {
+            return (env->mip & MIP_MSIP) > 0;
+        } else {
+            error_report("clint: invalid read: %08x", (uint32_t)addr);
+            return 0;
+        }
+    } else if (addr >= clint->timecmp_base &&
+        addr < clint->timecmp_base + (clint->num_harts << 3)) {
+        size_t hartid = (addr - clint->timecmp_base) >> 3;
+        CPUState *cpu = qemu_get_cpu(hartid);
+        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
+        if (!env) {
+            error_report("clint: invalid timecmp hartid: %zu", hartid);
+        } else if ((addr & 0x7) == 0) {
+            /* timecmp_lo */
+            uint64_t timecmp = env->timecmp;
+            return timecmp & 0xFFFFFFFF;
+        } else if ((addr & 0x7) == 4) {
+            /* timecmp_hi */
+            uint64_t timecmp = env->timecmp;
+            return (timecmp >> 32) & 0xFFFFFFFF;
+        } else {
+            error_report("clint: invalid read: %08x", (uint32_t)addr);
+            return 0;
+        }
+    } else if (addr == clint->time_base) {
+        /* time_lo */
+        return cpu_riscv_read_rtc() & 0xFFFFFFFF;
+    } else if (addr == clint->time_base + 4) {
+        /* time_hi */
+        return (cpu_riscv_read_rtc() >> 32) & 0xFFFFFFFF;
+    }
+
+    error_report("clint: invalid read: %08x", (uint32_t)addr);
+    return 0;
+}
+
+/* CPU wrote to rtc or timecmp register */
+static void sifive_clint_write(void *opaque, hwaddr addr, uint64_t value,
+        unsigned size)
+{
+    SiFiveCLINTState *clint = opaque;
+
+    if (addr >= clint->sip_base &&
+        addr < clint->sip_base + (clint->num_harts << 2)) {
+        size_t hartid = (addr - clint->sip_base) >> 2;
+        CPUState *cpu = qemu_get_cpu(hartid);
+        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
+        if (!env) {
+            error_report("clint: invalid timecmp hartid: %zu", hartid);
+        } else if ((addr & 0x3) == 0) {
+            riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_MSIP, value != 0);
+        } else {
+            error_report("clint: invalid sip write: %08x", (uint32_t)addr);
+        }
+        return;
+    } else if (addr >= clint->timecmp_base &&
+        addr < clint->timecmp_base + (clint->num_harts << 3)) {
+        size_t hartid = (addr - clint->timecmp_base) >> 3;
+        CPUState *cpu = qemu_get_cpu(hartid);
+        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
+        if (!env) {
+            error_report("clint: invalid timecmp hartid: %zu", hartid);
+        } else if ((addr & 0x7) == 0) {
+            /* timecmp_lo */
+            uint64_t timecmp = env->timecmp;
+            sifive_clint_write_timecmp(RISCV_CPU(cpu),
+                timecmp << 32 | (value & 0xFFFFFFFF));
+            return;
+        } else if ((addr & 0x7) == 4) {
+            /* timecmp_hi */
+            uint64_t timecmp = env->timecmp;
+            sifive_clint_write_timecmp(RISCV_CPU(cpu),
+                value << 32 | (timecmp & 0xFFFFFFFF));
+        } else {
+            error_report("clint: invalid timecmp write: %08x", (uint32_t)addr);
+        }
+        return;
+    } else if (addr == clint->time_base) {
+        /* time_lo */
+        error_report("clint: time_lo write not implemented");
+        return;
+    } else if (addr == clint->time_base + 4) {
+        /* time_hi */
+        error_report("clint: time_hi write not implemented");
+        return;
+    }
+
+    error_report("clint: invalid write: %08x", (uint32_t)addr);
+}
+
+static const MemoryRegionOps sifive_clint_ops = {
+    .read = sifive_clint_read,
+    .write = sifive_clint_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static Property sifive_clint_properties[] = {
+    DEFINE_PROP_UINT32("num-harts", SiFiveCLINTState, num_harts, 0),
+    DEFINE_PROP_UINT32("sip-base", SiFiveCLINTState, sip_base, 0),
+    DEFINE_PROP_UINT32("timecmp-base", SiFiveCLINTState, timecmp_base, 0),
+    DEFINE_PROP_UINT32("time-base", SiFiveCLINTState, time_base, 0),
+    DEFINE_PROP_UINT32("aperture-size", SiFiveCLINTState, aperture_size, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void sifive_clint_realize(DeviceState *dev, Error **errp)
+{
+    SiFiveCLINTState *s = SIFIVE_CLINT(dev);
+    memory_region_init_io(&s->mmio, OBJECT(dev), &sifive_clint_ops, s,
+                          TYPE_SIFIVE_CLINT, s->aperture_size);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
+}
+
+static void sifive_clint_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    dc->realize = sifive_clint_realize;
+    dc->props = sifive_clint_properties;
+}
+
+static const TypeInfo sifive_clint_info = {
+    .name          = TYPE_SIFIVE_CLINT,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFiveCLINTState),
+    .class_init    = sifive_clint_class_init,
+};
+
+static void sifive_clint_register_types(void)
+{
+    type_register_static(&sifive_clint_info);
+}
+
+type_init(sifive_clint_register_types)
+
+
+/*
+ * Create CLINT device.
+ */
+DeviceState *sifive_clint_create(hwaddr addr, hwaddr size, uint32_t num_harts,
+    uint32_t sip_base, uint32_t timecmp_base, uint32_t time_base)
+{
+    int i;
+    for (i = 0; i < num_harts; i++) {
+        CPUState *cpu = qemu_get_cpu(i);
+        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
+        if (!env) {
+            continue;
+        }
+        env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                  &sifive_clint_timer_cb, cpu);
+        env->timecmp = 0;
+    }
+
+    DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_CLINT);
+    qdev_prop_set_uint32(dev, "num-harts", num_harts);
+    qdev_prop_set_uint32(dev, "sip-base", sip_base);
+    qdev_prop_set_uint32(dev, "timecmp-base", timecmp_base);
+    qdev_prop_set_uint32(dev, "time-base", time_base);
+    qdev_prop_set_uint32(dev, "aperture-size", size);
+    qdev_init_nofail(dev);
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
+    return dev;
+}
diff --git a/hw/riscv/sifive_e.c b/hw/riscv/sifive_e.c
new file mode 100644
index 0000000000..19eca36ff4
--- /dev/null
+++ b/hw/riscv/sifive_e.c
@@ -0,0 +1,234 @@
+/*
+ * QEMU RISC-V Board Compatible with SiFive Freedom E SDK
+ *
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * Provides a board compatible with the SiFive Freedom E SDK:
+ *
+ * 0) UART
+ * 1) CLINT (Core Level Interruptor)
+ * 2) PLIC (Platform Level Interrupt Controller)
+ * 3) PRCI (Power, Reset, Clock, Interrupt)
+ * 4) Registers emulated as RAM: AON, GPIO, QSPI, PWM
+ * 5) Flash memory emulated as RAM
+ *
+ * The Mask ROM reset vector jumps to the flash payload at 0x2040_0000.
+ * The OTP ROM and Flash boot code will be emulated in a future version.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "hw/hw.h"
+#include "hw/boards.h"
+#include "hw/loader.h"
+#include "hw/sysbus.h"
+#include "hw/char/serial.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/riscv_hart.h"
+#include "hw/riscv/sifive_plic.h"
+#include "hw/riscv/sifive_clint.h"
+#include "hw/riscv/sifive_prci.h"
+#include "hw/riscv/sifive_uart.h"
+#include "hw/riscv/sifive_e.h"
+#include "chardev/char.h"
+#include "sysemu/arch_init.h"
+#include "exec/address-spaces.h"
+#include "elf.h"
+
+static const struct MemmapEntry {
+    hwaddr base;
+    hwaddr size;
+} sifive_e_memmap[] = {
+    [SIFIVE_E_DEBUG] =    {        0x0,      0x100 },
+    [SIFIVE_E_MROM] =     {     0x1000,     0x2000 },
+    [SIFIVE_E_OTP] =      {    0x20000,     0x2000 },
+    [SIFIVE_E_CLINT] =    {  0x2000000,    0x10000 },
+    [SIFIVE_E_PLIC] =     {  0xc000000,  0x4000000 },
+    [SIFIVE_E_AON] =      { 0x10000000,     0x8000 },
+    [SIFIVE_E_PRCI] =     { 0x10008000,     0x8000 },
+    [SIFIVE_E_OTP_CTRL] = { 0x10010000,     0x1000 },
+    [SIFIVE_E_GPIO0] =    { 0x10012000,     0x1000 },
+    [SIFIVE_E_UART0] =    { 0x10013000,     0x1000 },
+    [SIFIVE_E_QSPI0] =    { 0x10014000,     0x1000 },
+    [SIFIVE_E_PWM0] =     { 0x10015000,     0x1000 },
+    [SIFIVE_E_UART1] =    { 0x10023000,     0x1000 },
+    [SIFIVE_E_QSPI1] =    { 0x10024000,     0x1000 },
+    [SIFIVE_E_PWM1] =     { 0x10025000,     0x1000 },
+    [SIFIVE_E_QSPI2] =    { 0x10034000,     0x1000 },
+    [SIFIVE_E_PWM2] =     { 0x10035000,     0x1000 },
+    [SIFIVE_E_XIP] =      { 0x20000000, 0x20000000 },
+    [SIFIVE_E_DTIM] =     { 0x80000000,     0x4000 }
+};
+
+static void copy_le32_to_phys(hwaddr pa, uint32_t *rom, size_t len)
+{
+    int i;
+    for (i = 0; i < (len >> 2); i++) {
+        stl_phys(&address_space_memory, pa + (i << 2), rom[i]);
+    }
+}
+
+static uint64_t identity_translate(void *opaque, uint64_t addr)
+{
+    return addr;
+}
+
+static uint64_t load_kernel(const char *kernel_filename)
+{
+    uint64_t kernel_entry, kernel_high;
+
+    if (load_elf(kernel_filename, identity_translate, NULL,
+                 &kernel_entry, NULL, &kernel_high,
+                 0, ELF_MACHINE, 1, 0) < 0) {
+        error_report("qemu: could not load kernel '%s'", kernel_filename);
+        exit(1);
+    }
+    return kernel_entry;
+}
+
+static void sifive_mmio_emulate(MemoryRegion *parent, const char *name,
+                             uintptr_t offset, uintptr_t length)
+{
+    MemoryRegion *mock_mmio = g_new(MemoryRegion, 1);
+    memory_region_init_ram(mock_mmio, NULL, name, length, &error_fatal);
+    memory_region_add_subregion(parent, offset, mock_mmio);
+}
+
+static void riscv_sifive_e_init(MachineState *machine)
+{
+    const struct MemmapEntry *memmap = sifive_e_memmap;
+
+    SiFiveEState *s = g_new0(SiFiveEState, 1);
+    MemoryRegion *sys_mem = get_system_memory();
+    MemoryRegion *main_mem = g_new(MemoryRegion, 1);
+    MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
+    MemoryRegion *xip_mem = g_new(MemoryRegion, 1);
+
+    /* Initialize SOC */
+    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_HART_ARRAY);
+    object_property_add_child(OBJECT(machine), "soc", OBJECT(&s->soc),
+                              &error_abort);
+    object_property_set_str(OBJECT(&s->soc), SIFIVE_E_CPU, "cpu-type",
+                            &error_abort);
+    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
+                            &error_abort);
+    object_property_set_bool(OBJECT(&s->soc), true, "realized",
+                            &error_abort);
+
+    /* Data Tightly Integrated Memory */
+    memory_region_init_ram(main_mem, NULL, "riscv.sifive.e.ram",
+        memmap[SIFIVE_E_DTIM].size, &error_fatal);
+    memory_region_add_subregion(sys_mem,
+        memmap[SIFIVE_E_DTIM].base, main_mem);
+
+    /* Mask ROM */
+    memory_region_init_ram(mask_rom, NULL, "riscv.sifive.e.mrom",
+        memmap[SIFIVE_E_MROM].size, &error_fatal);
+    memory_region_add_subregion(sys_mem,
+        memmap[SIFIVE_E_MROM].base, mask_rom);
+
+    /* MMIO */
+    s->plic = sifive_plic_create(memmap[SIFIVE_E_PLIC].base,
+        (char *)SIFIVE_E_PLIC_HART_CONFIG,
+        SIFIVE_E_PLIC_NUM_SOURCES,
+        SIFIVE_E_PLIC_NUM_PRIORITIES,
+        SIFIVE_E_PLIC_PRIORITY_BASE,
+        SIFIVE_E_PLIC_PENDING_BASE,
+        SIFIVE_E_PLIC_ENABLE_BASE,
+        SIFIVE_E_PLIC_ENABLE_STRIDE,
+        SIFIVE_E_PLIC_CONTEXT_BASE,
+        SIFIVE_E_PLIC_CONTEXT_STRIDE,
+        memmap[SIFIVE_E_PLIC].size);
+    sifive_clint_create(memmap[SIFIVE_E_CLINT].base,
+        memmap[SIFIVE_E_CLINT].size, smp_cpus,
+        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.aon",
+        memmap[SIFIVE_E_AON].base, memmap[SIFIVE_E_AON].size);
+    sifive_prci_create(memmap[SIFIVE_E_PRCI].base);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.gpio0",
+        memmap[SIFIVE_E_GPIO0].base, memmap[SIFIVE_E_GPIO0].size);
+    sifive_uart_create(sys_mem, memmap[SIFIVE_E_UART0].base,
+        serial_hds[0], SIFIVE_PLIC(s->plic)->irqs[SIFIVE_E_UART0_IRQ]);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.qspi0",
+        memmap[SIFIVE_E_QSPI0].base, memmap[SIFIVE_E_QSPI0].size);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.pwm0",
+        memmap[SIFIVE_E_PWM0].base, memmap[SIFIVE_E_PWM0].size);
+    /* sifive_uart_create(sys_mem, memmap[SIFIVE_E_UART1].base,
+        serial_hds[1], SIFIVE_PLIC(s->plic)->irqs[SIFIVE_E_UART1_IRQ]); */
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.qspi1",
+        memmap[SIFIVE_E_QSPI1].base, memmap[SIFIVE_E_QSPI1].size);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.pwm1",
+        memmap[SIFIVE_E_PWM1].base, memmap[SIFIVE_E_PWM1].size);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.qspi2",
+        memmap[SIFIVE_E_QSPI2].base, memmap[SIFIVE_E_QSPI2].size);
+    sifive_mmio_emulate(sys_mem, "riscv.sifive.e.pwm2",
+        memmap[SIFIVE_E_PWM2].base, memmap[SIFIVE_E_PWM2].size);
+
+    /* Flash memory */
+    memory_region_init_ram(xip_mem, NULL, "riscv.sifive.e.xip",
+        memmap[SIFIVE_E_XIP].size, &error_fatal);
+    memory_region_set_readonly(xip_mem, true);
+    memory_region_add_subregion(sys_mem, memmap[SIFIVE_E_XIP].base, xip_mem);
+
+    /* Mask ROM reset vector */
+    uint32_t reset_vec[2] = {
+        0x204002b7,        /* 0x1000: lui     t0,0x20400 */
+        0x00028067,        /* 0x1004: jr      t0 */
+    };
+
+    /* copy in the reset vector */
+    copy_le32_to_phys(memmap[SIFIVE_E_MROM].base, reset_vec, sizeof(reset_vec));
+    memory_region_set_readonly(mask_rom, true);
+
+    if (machine->kernel_filename) {
+        load_kernel(machine->kernel_filename);
+    }
+}
+
+static int riscv_sifive_e_sysbus_device_init(SysBusDevice *sysbusdev)
+{
+    return 0;
+}
+
+static void riscv_sifive_e_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    k->init = riscv_sifive_e_sysbus_device_init;
+}
+
+static const TypeInfo riscv_sifive_e_device = {
+    .name          = TYPE_SIFIVE_E,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFiveEState),
+    .class_init    = riscv_sifive_e_class_init,
+};
+
+static void riscv_sifive_e_machine_init(MachineClass *mc)
+{
+    mc->desc = "RISC-V Board compatible with SiFive E SDK";
+    mc->init = riscv_sifive_e_init;
+    mc->max_cpus = 1;
+}
+
+DEFINE_MACHINE("sifive_e", riscv_sifive_e_machine_init)
+
+static void riscv_sifive_e_register_types(void)
+{
+    type_register_static(&riscv_sifive_e_device);
+}
+
+type_init(riscv_sifive_e_register_types);
diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c
new file mode 100644
index 0000000000..874de2ebaf
--- /dev/null
+++ b/hw/riscv/sifive_plic.c
@@ -0,0 +1,505 @@
+/*
+ * SiFive PLIC (Platform Level Interrupt Controller)
+ *
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * This provides a parameterizable interrupt controller based on SiFive's PLIC.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "hw/sysbus.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/sifive_plic.h"
+
+#define RISCV_DEBUG_PLIC 0
+
+static PLICMode char_to_mode(char c)
+{
+    switch (c) {
+    case 'U': return PLICMode_U;
+    case 'S': return PLICMode_S;
+    case 'H': return PLICMode_H;
+    case 'M': return PLICMode_M;
+    default:
+        error_report("plic: invalid mode '%c'", c);
+        exit(1);
+    }
+}
+
+static char mode_to_char(PLICMode m)
+{
+    switch (m) {
+    case PLICMode_U: return 'U';
+    case PLICMode_S: return 'S';
+    case PLICMode_H: return 'H';
+    case PLICMode_M: return 'M';
+    default: return '?';
+    }
+}
+
+static void sifive_plic_print_state(SiFivePLICState *plic)
+{
+    int i;
+    int addrid;
+
+    /* pending */
+    qemu_log("pending       : ");
+    for (i = plic->bitfield_words - 1; i >= 0; i--) {
+        qemu_log("%08x", plic->pending[i]);
+    }
+    qemu_log("\n");
+
+    /* pending */
+    qemu_log("claimed       : ");
+    for (i = plic->bitfield_words - 1; i >= 0; i--) {
+        qemu_log("%08x", plic->claimed[i]);
+    }
+    qemu_log("\n");
+
+    for (addrid = 0; addrid < plic->num_addrs; addrid++) {
+        qemu_log("hart%d-%c enable: ",
+            plic->addr_config[addrid].hartid,
+            mode_to_char(plic->addr_config[addrid].mode));
+        for (i = plic->bitfield_words - 1; i >= 0; i--) {
+            qemu_log("%08x", plic->enable[addrid * plic->bitfield_words + i]);
+        }
+        qemu_log("\n");
+    }
+}
+
+static
+void sifive_plic_set_pending(SiFivePLICState *plic, int irq, bool pending)
+{
+    qemu_mutex_lock(&plic->lock);
+    uint32_t word = irq >> 5;
+    if (pending) {
+        plic->pending[word] |= (1 << (irq & 31));
+    } else {
+        plic->pending[word] &= ~(1 << (irq & 31));
+    }
+    qemu_mutex_unlock(&plic->lock);
+}
+
+static
+void sifive_plic_set_claimed(SiFivePLICState *plic, int irq, bool claimed)
+{
+    qemu_mutex_lock(&plic->lock);
+    uint32_t word = irq >> 5;
+    if (claimed) {
+        plic->claimed[word] |= (1 << (irq & 31));
+    } else {
+        plic->claimed[word] &= ~(1 << (irq & 31));
+    }
+    qemu_mutex_unlock(&plic->lock);
+}
+
+static
+int sifive_plic_num_irqs_pending(SiFivePLICState *plic, uint32_t addrid)
+{
+    int i, j, count = 0;
+    for (i = 0; i < plic->bitfield_words; i++) {
+        uint32_t pending_enabled_not_claimed =
+            (plic->pending[i] & ~plic->claimed[i]) &
+            plic->enable[addrid * plic->bitfield_words + i];
+        if (!pending_enabled_not_claimed) {
+            continue;
+        }
+        for (j = 0; j < 32; j++) {
+            int irq = (i << 5) + j;
+            uint32_t prio = plic->source_priority[irq];
+            int enabled = pending_enabled_not_claimed & (1 << j);
+            if (enabled && prio > plic->target_priority[addrid]) {
+                count++;
+            }
+        }
+    }
+    return count;
+}
+
+static void sifive_plic_update(SiFivePLICState *plic)
+{
+    int addrid;
+
+    /* raise irq on harts where this irq is enabled */
+    for (addrid = 0; addrid < plic->num_addrs; addrid++) {
+        uint32_t hartid = plic->addr_config[addrid].hartid;
+        PLICMode mode = plic->addr_config[addrid].mode;
+        CPUState *cpu = qemu_get_cpu(hartid);
+        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
+        if (!env) {
+            continue;
+        }
+        int level = sifive_plic_num_irqs_pending(plic, addrid) > 0;
+        switch (mode) {
+        case PLICMode_M:
+            riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_MEIP, level);
+            break;
+        case PLICMode_S:
+            riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_SEIP, level);
+            break;
+        default:
+            break;
+        }
+    }
+
+    if (RISCV_DEBUG_PLIC) {
+        sifive_plic_print_state(plic);
+    }
+}
+
+void sifive_plic_raise_irq(SiFivePLICState *plic, uint32_t irq)
+{
+    sifive_plic_set_pending(plic, irq, true);
+    sifive_plic_update(plic);
+}
+
+void sifive_plic_lower_irq(SiFivePLICState *plic, uint32_t irq)
+{
+    sifive_plic_set_pending(plic, irq, false);
+    sifive_plic_update(plic);
+}
+
+static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
+{
+    int i, j;
+    for (i = 0; i < plic->bitfield_words; i++) {
+        uint32_t pending_enabled_not_claimed =
+            (plic->pending[i] & ~plic->claimed[i]) &
+            plic->enable[addrid * plic->bitfield_words + i];
+        if (!pending_enabled_not_claimed) {
+            continue;
+        }
+        for (j = 0; j < 32; j++) {
+            int irq = (i << 5) + j;
+            uint32_t prio = plic->source_priority[irq];
+            int enabled = pending_enabled_not_claimed & (1 << j);
+            if (enabled && prio > plic->target_priority[addrid]) {
+                sifive_plic_set_pending(plic, irq, false);
+                sifive_plic_set_claimed(plic, irq, true);
+                return irq;
+            }
+        }
+    }
+    return 0;
+}
+
+static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size)
+{
+    SiFivePLICState *plic = opaque;
+
+    /* writes must be 4 byte words */
+    if ((addr & 0x3) != 0) {
+        goto err;
+    }
+
+    if (addr >= plic->priority_base && /* 4 bytes per source */
+        addr < plic->priority_base + (plic->num_sources << 2))
+    {
+        uint32_t irq = (addr - plic->priority_base) >> 2;
+        if (RISCV_DEBUG_PLIC) {
+            qemu_log("plic: read priority: irq=%d priority=%d\n",
+                irq, plic->source_priority[irq]);
+        }
+        return plic->source_priority[irq];
+    } else if (addr >= plic->pending_base && /* 1 bit per source */
+               addr < plic->pending_base + (plic->num_sources >> 3))
+    {
+        uint32_t word = (addr - plic->priority_base) >> 2;
+        if (RISCV_DEBUG_PLIC) {
+            qemu_log("plic: read pending: word=%d value=%d\n",
+                word, plic->pending[word]);
+        }
+        return plic->pending[word];
+    } else if (addr >= plic->enable_base && /* 1 bit per source */
+             addr < plic->enable_base + plic->num_addrs * plic->enable_stride)
+    {
+        uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride;
+        uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2;
+        if (wordid < plic->bitfield_words) {
+            if (RISCV_DEBUG_PLIC) {
+                qemu_log("plic: read enable: hart%d-%c word=%d value=%x\n",
+                    plic->addr_config[addrid].hartid,
+                    mode_to_char(plic->addr_config[addrid].mode), wordid,
+                    plic->enable[addrid * plic->bitfield_words + wordid]);
+            }
+            return plic->enable[addrid * plic->bitfield_words + wordid];
+        }
+    } else if (addr >= plic->context_base && /* 1 bit per source */
+             addr < plic->context_base + plic->num_addrs * plic->context_stride)
+    {
+        uint32_t addrid = (addr - plic->context_base) / plic->context_stride;
+        uint32_t contextid = (addr & (plic->context_stride - 1));
+        if (contextid == 0) {
+            if (RISCV_DEBUG_PLIC) {
+                qemu_log("plic: read priority: hart%d-%c priority=%x\n",
+                    plic->addr_config[addrid].hartid,
+                    mode_to_char(plic->addr_config[addrid].mode),
+                    plic->target_priority[addrid]);
+            }
+            return plic->target_priority[addrid];
+        } else if (contextid == 4) {
+            uint32_t value = sifive_plic_claim(plic, addrid);
+            if (RISCV_DEBUG_PLIC) {
+                qemu_log("plic: read claim: hart%d-%c irq=%x\n",
+                    plic->addr_config[addrid].hartid,
+                    mode_to_char(plic->addr_config[addrid].mode),
+                    value);
+                sifive_plic_print_state(plic);
+            }
+            return value;
+        }
+    }
+
+err:
+    error_report("plic: invalid register read: %08x", (uint32_t)addr);
+    return 0;
+}
+
+static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value,
+        unsigned size)
+{
+    SiFivePLICState *plic = opaque;
+
+    /* writes must be 4 byte words */
+    if ((addr & 0x3) != 0) {
+        goto err;
+    }
+
+    if (addr >= plic->priority_base && /* 4 bytes per source */
+        addr < plic->priority_base + (plic->num_sources << 2))
+    {
+        uint32_t irq = (addr - plic->priority_base) >> 2;
+        plic->source_priority[irq] = value & 7;
+        if (RISCV_DEBUG_PLIC) {
+            qemu_log("plic: write priority: irq=%d priority=%d\n",
+                irq, plic->source_priority[irq]);
+        }
+        return;
+    } else if (addr >= plic->pending_base && /* 1 bit per source */
+               addr < plic->pending_base + (plic->num_sources >> 3))
+    {
+        error_report("plic: invalid pending write: %08x", (uint32_t)addr);
+        return;
+    } else if (addr >= plic->enable_base && /* 1 bit per source */
+        addr < plic->enable_base + plic->num_addrs * plic->enable_stride)
+    {
+        uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride;
+        uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2;
+        if (wordid < plic->bitfield_words) {
+            plic->enable[addrid * plic->bitfield_words + wordid] = value;
+            if (RISCV_DEBUG_PLIC) {
+                qemu_log("plic: write enable: hart%d-%c word=%d value=%x\n",
+                    plic->addr_config[addrid].hartid,
+                    mode_to_char(plic->addr_config[addrid].mode), wordid,
+                    plic->enable[addrid * plic->bitfield_words + wordid]);
+            }
+            return;
+        }
+    } else if (addr >= plic->context_base && /* 4 bytes per reg */
+        addr < plic->context_base + plic->num_addrs * plic->context_stride)
+    {
+        uint32_t addrid = (addr - plic->context_base) / plic->context_stride;
+        uint32_t contextid = (addr & (plic->context_stride - 1));
+        if (contextid == 0) {
+            if (RISCV_DEBUG_PLIC) {
+                qemu_log("plic: write priority: hart%d-%c priority=%x\n",
+                    plic->addr_config[addrid].hartid,
+                    mode_to_char(plic->addr_config[addrid].mode),
+                    plic->target_priority[addrid]);
+            }
+            if (value <= plic->num_priorities) {
+                plic->target_priority[addrid] = value;
+                sifive_plic_update(plic);
+            }
+            return;
+        } else if (contextid == 4) {
+            if (RISCV_DEBUG_PLIC) {
+                qemu_log("plic: write claim: hart%d-%c irq=%x\n",
+                    plic->addr_config[addrid].hartid,
+                    mode_to_char(plic->addr_config[addrid].mode),
+                    (uint32_t)value);
+            }
+            if (value < plic->num_sources) {
+                sifive_plic_set_claimed(plic, value, false);
+                sifive_plic_update(plic);
+            }
+            return;
+        }
+    }
+
+err:
+    error_report("plic: invalid register write: %08x", (uint32_t)addr);
+}
+
+static const MemoryRegionOps sifive_plic_ops = {
+    .read = sifive_plic_read,
+    .write = sifive_plic_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static Property sifive_plic_properties[] = {
+    DEFINE_PROP_STRING("hart-config", SiFivePLICState, hart_config),
+    DEFINE_PROP_UINT32("num-sources", SiFivePLICState, num_sources, 0),
+    DEFINE_PROP_UINT32("num-priorities", SiFivePLICState, num_priorities, 0),
+    DEFINE_PROP_UINT32("priority-base", SiFivePLICState, priority_base, 0),
+    DEFINE_PROP_UINT32("pending-base", SiFivePLICState, pending_base, 0),
+    DEFINE_PROP_UINT32("enable-base", SiFivePLICState, enable_base, 0),
+    DEFINE_PROP_UINT32("enable-stride", SiFivePLICState, enable_stride, 0),
+    DEFINE_PROP_UINT32("context-base", SiFivePLICState, context_base, 0),
+    DEFINE_PROP_UINT32("context-stride", SiFivePLICState, context_stride, 0),
+    DEFINE_PROP_UINT32("aperture-size", SiFivePLICState, aperture_size, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+/*
+ * parse PLIC hart/mode address offset config
+ *
+ * "M"              1 hart with M mode
+ * "MS,MS"          2 harts, 0-1 with M and S mode
+ * "M,MS,MS,MS,MS"  5 harts, 0 with M mode, 1-5 with M and S mode
+ */
+static void parse_hart_config(SiFivePLICState *plic)
+{
+    int addrid, hartid, modes;
+    const char *p;
+    char c;
+
+    /* count and validate hart/mode combinations */
+    addrid = 0, hartid = 0, modes = 0;
+    p = plic->hart_config;
+    while ((c = *p++)) {
+        if (c == ',') {
+            addrid += __builtin_popcount(modes);
+            modes = 0;
+            hartid++;
+        } else {
+            int m = 1 << char_to_mode(c);
+            if (modes == (modes | m)) {
+                error_report("plic: duplicate mode '%c' in config: %s",
+                             c, plic->hart_config);
+                exit(1);
+            }
+            modes |= m;
+        }
+    }
+    if (modes) {
+        addrid += __builtin_popcount(modes);
+    }
+    hartid++;
+
+    /* store hart/mode combinations */
+    plic->num_addrs = addrid;
+    plic->addr_config = g_new(PLICAddr, plic->num_addrs);
+    addrid = 0, hartid = 0;
+    p = plic->hart_config;
+    while ((c = *p++)) {
+        if (c == ',') {
+            hartid++;
+        } else {
+            plic->addr_config[addrid].addrid = addrid;
+            plic->addr_config[addrid].hartid = hartid;
+            plic->addr_config[addrid].mode = char_to_mode(c);
+            addrid++;
+        }
+    }
+}
+
+static void sifive_plic_irq_request(void *opaque, int irq, int level)
+{
+    SiFivePLICState *plic = opaque;
+    if (RISCV_DEBUG_PLIC) {
+        qemu_log("sifive_plic_irq_request: irq=%d level=%d\n", irq, level);
+    }
+    sifive_plic_set_pending(plic, irq, level > 0);
+    sifive_plic_update(plic);
+}
+
+static void sifive_plic_realize(DeviceState *dev, Error **errp)
+{
+    SiFivePLICState *plic = SIFIVE_PLIC(dev);
+    int i;
+
+    memory_region_init_io(&plic->mmio, OBJECT(dev), &sifive_plic_ops, plic,
+                          TYPE_SIFIVE_PLIC, plic->aperture_size);
+    parse_hart_config(plic);
+    qemu_mutex_init(&plic->lock);
+    plic->bitfield_words = (plic->num_sources + 31) >> 5;
+    plic->source_priority = g_new0(uint32_t, plic->num_sources);
+    plic->target_priority = g_new(uint32_t, plic->num_addrs);
+    plic->pending = g_new0(uint32_t, plic->bitfield_words);
+    plic->claimed = g_new0(uint32_t, plic->bitfield_words);
+    plic->enable = g_new0(uint32_t, plic->bitfield_words * plic->num_addrs);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &plic->mmio);
+    plic->irqs = g_new0(qemu_irq, plic->num_sources + 1);
+    for (i = 0; i <= plic->num_sources; i++) {
+        plic->irqs[i] = qemu_allocate_irq(sifive_plic_irq_request, plic, i);
+    }
+}
+
+static void sifive_plic_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->props = sifive_plic_properties;
+    dc->realize = sifive_plic_realize;
+}
+
+static const TypeInfo sifive_plic_info = {
+    .name          = TYPE_SIFIVE_PLIC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFivePLICState),
+    .class_init    = sifive_plic_class_init,
+};
+
+static void sifive_plic_register_types(void)
+{
+    type_register_static(&sifive_plic_info);
+}
+
+type_init(sifive_plic_register_types)
+
+/*
+ * Create PLIC device.
+ */
+DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
+    uint32_t num_sources, uint32_t num_priorities,
+    uint32_t priority_base, uint32_t pending_base,
+    uint32_t enable_base, uint32_t enable_stride,
+    uint32_t context_base, uint32_t context_stride,
+    uint32_t aperture_size)
+{
+    DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_PLIC);
+    assert(enable_stride == (enable_stride & -enable_stride));
+    assert(context_stride == (context_stride & -context_stride));
+    qdev_prop_set_string(dev, "hart-config", hart_config);
+    qdev_prop_set_uint32(dev, "num-sources", num_sources);
+    qdev_prop_set_uint32(dev, "num-priorities", num_priorities);
+    qdev_prop_set_uint32(dev, "priority-base", priority_base);
+    qdev_prop_set_uint32(dev, "pending-base", pending_base);
+    qdev_prop_set_uint32(dev, "enable-base", enable_base);
+    qdev_prop_set_uint32(dev, "enable-stride", enable_stride);
+    qdev_prop_set_uint32(dev, "context-base", context_base);
+    qdev_prop_set_uint32(dev, "context-stride", context_stride);
+    qdev_prop_set_uint32(dev, "aperture-size", aperture_size);
+    qdev_init_nofail(dev);
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
+    return dev;
+}
diff --git a/hw/riscv/sifive_prci.c b/hw/riscv/sifive_prci.c
new file mode 100644
index 0000000000..0910ea32c1
--- /dev/null
+++ b/hw/riscv/sifive_prci.c
@@ -0,0 +1,89 @@
+/*
+ * QEMU SiFive PRCI (Power, Reset, Clock, Interrupt)
+ *
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * Simple model of the PRCI to emulate register reads made by the SDK BSP
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/sifive_prci.h"
+
+/* currently implements enough to mock freedom-e-sdk BSP clock programming */
+
+static uint64_t sifive_prci_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    if (addr == 0 /* PRCI_HFROSCCFG */) {
+        return 1 << 31; /* ROSC_RDY */
+    }
+    if (addr == 8 /* PRCI_PLLCFG    */) {
+        return 1 << 31; /* PLL_LOCK */
+    }
+    hw_error("%s: read: addr=0x%x\n", __func__, (int)addr);
+    return 0;
+}
+
+static void sifive_prci_write(void *opaque, hwaddr addr,
+           uint64_t val64, unsigned int size)
+{
+    /* discard writes */
+}
+
+static const MemoryRegionOps sifive_prci_ops = {
+    .read = sifive_prci_read,
+    .write = sifive_prci_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static void sifive_prci_init(Object *obj)
+{
+    SiFivePRCIState *s = SIFIVE_PRCI(obj);
+
+    memory_region_init_io(&s->mmio, obj, &sifive_prci_ops, s,
+                          TYPE_SIFIVE_PRCI, 0x8000);
+    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static const TypeInfo sifive_prci_info = {
+    .name          = TYPE_SIFIVE_PRCI,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFivePRCIState),
+    .instance_init = sifive_prci_init,
+};
+
+static void sifive_prci_register_types(void)
+{
+    type_register_static(&sifive_prci_info);
+}
+
+type_init(sifive_prci_register_types)
+
+
+/*
+ * Create PRCI device.
+ */
+DeviceState *sifive_prci_create(hwaddr addr)
+{
+    DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_PRCI);
+    qdev_init_nofail(dev);
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
+    return dev;
+}
diff --git a/hw/riscv/sifive_test.c b/hw/riscv/sifive_test.c
new file mode 100644
index 0000000000..8abd2cd525
--- /dev/null
+++ b/hw/riscv/sifive_test.c
@@ -0,0 +1,93 @@
+/*
+ * QEMU SiFive Test Finisher
+ *
+ * Copyright (c) 2018 SiFive, Inc.
+ *
+ * Test finisher memory mapped device used to exit simulation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/sifive_test.h"
+
+static uint64_t sifive_test_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    return 0;
+}
+
+static void sifive_test_write(void *opaque, hwaddr addr,
+           uint64_t val64, unsigned int size)
+{
+    if (addr == 0) {
+        int status = val64 & 0xffff;
+        int code = (val64 >> 16) & 0xffff;
+        switch (status) {
+        case FINISHER_FAIL:
+            exit(code);
+        case FINISHER_PASS:
+            exit(0);
+        default:
+            break;
+        }
+    }
+    hw_error("%s: write: addr=0x%x val=0x%016" PRIx64 "\n",
+        __func__, (int)addr, val64);
+}
+
+static const MemoryRegionOps sifive_test_ops = {
+    .read = sifive_test_read,
+    .write = sifive_test_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static void sifive_test_init(Object *obj)
+{
+    SiFiveTestState *s = SIFIVE_TEST(obj);
+
+    memory_region_init_io(&s->mmio, obj, &sifive_test_ops, s,
+                          TYPE_SIFIVE_TEST, 0x1000);
+    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static const TypeInfo sifive_test_info = {
+    .name          = TYPE_SIFIVE_TEST,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFiveTestState),
+    .instance_init = sifive_test_init,
+};
+
+static void sifive_test_register_types(void)
+{
+    type_register_static(&sifive_test_info);
+}
+
+type_init(sifive_test_register_types)
+
+
+/*
+ * Create Test device.
+ */
+DeviceState *sifive_test_create(hwaddr addr)
+{
+    DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_TEST);
+    qdev_init_nofail(dev);
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
+    return dev;
+}
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
new file mode 100644
index 0000000000..1c2deefa6c
--- /dev/null
+++ b/hw/riscv/sifive_u.c
@@ -0,0 +1,339 @@
+/*
+ * QEMU RISC-V Board Compatible with SiFive Freedom U SDK
+ *
+ * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * Provides a board compatible with the SiFive Freedom U SDK:
+ *
+ * 0) UART
+ * 1) CLINT (Core Level Interruptor)
+ * 2) PLIC (Platform Level Interrupt Controller)
+ *
+ * This board currently uses a hardcoded devicetree that indicates one hart.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "hw/hw.h"
+#include "hw/boards.h"
+#include "hw/loader.h"
+#include "hw/sysbus.h"
+#include "hw/char/serial.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/riscv_hart.h"
+#include "hw/riscv/sifive_plic.h"
+#include "hw/riscv/sifive_clint.h"
+#include "hw/riscv/sifive_uart.h"
+#include "hw/riscv/sifive_prci.h"
+#include "hw/riscv/sifive_u.h"
+#include "chardev/char.h"
+#include "sysemu/arch_init.h"
+#include "sysemu/device_tree.h"
+#include "exec/address-spaces.h"
+#include "elf.h"
+
+static const struct MemmapEntry {
+    hwaddr base;
+    hwaddr size;
+} sifive_u_memmap[] = {
+    [SIFIVE_U_DEBUG] =    {        0x0,      0x100 },
+    [SIFIVE_U_MROM] =     {     0x1000,     0x2000 },
+    [SIFIVE_U_CLINT] =    {  0x2000000,    0x10000 },
+    [SIFIVE_U_PLIC] =     {  0xc000000,  0x4000000 },
+    [SIFIVE_U_UART0] =    { 0x10013000,     0x1000 },
+    [SIFIVE_U_UART1] =    { 0x10023000,     0x1000 },
+    [SIFIVE_U_DRAM] =     { 0x80000000,        0x0 },
+};
+
+static void copy_le32_to_phys(hwaddr pa, uint32_t *rom, size_t len)
+{
+    int i;
+    for (i = 0; i < (len >> 2); i++) {
+        stl_phys(&address_space_memory, pa + (i << 2), rom[i]);
+    }
+}
+
+static uint64_t identity_translate(void *opaque, uint64_t addr)
+{
+    return addr;
+}
+
+static uint64_t load_kernel(const char *kernel_filename)
+{
+    uint64_t kernel_entry, kernel_high;
+
+    if (load_elf(kernel_filename, identity_translate, NULL,
+                 &kernel_entry, NULL, &kernel_high,
+                 0, ELF_MACHINE, 1, 0) < 0) {
+        error_report("qemu: could not load kernel '%s'", kernel_filename);
+        exit(1);
+    }
+    return kernel_entry;
+}
+
+static void create_fdt(SiFiveUState *s, const struct MemmapEntry *memmap,
+    uint64_t mem_size, const char *cmdline)
+{
+    void *fdt;
+    int cpu;
+    uint32_t *cells;
+    char *nodename;
+    uint32_t plic_phandle;
+
+    fdt = s->fdt = create_device_tree(&s->fdt_size);
+    if (!fdt) {
+        error_report("create_device_tree() failed");
+        exit(1);
+    }
+
+    qemu_fdt_setprop_string(fdt, "/", "model", "ucbbar,spike-bare,qemu");
+    qemu_fdt_setprop_string(fdt, "/", "compatible", "ucbbar,spike-bare-dev");
+    qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2);
+    qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2);
+
+    qemu_fdt_add_subnode(fdt, "/soc");
+    qemu_fdt_setprop(fdt, "/soc", "ranges", NULL, 0);
+    qemu_fdt_setprop_string(fdt, "/soc", "compatible", "ucbbar,spike-bare-soc");
+    qemu_fdt_setprop_cell(fdt, "/soc", "#size-cells", 0x2);
+    qemu_fdt_setprop_cell(fdt, "/soc", "#address-cells", 0x2);
+
+    nodename = g_strdup_printf("/memory@%lx",
+        (long)memmap[SIFIVE_U_DRAM].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        memmap[SIFIVE_U_DRAM].base >> 32, memmap[SIFIVE_U_DRAM].base,
+        mem_size >> 32, mem_size);
+    qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory");
+    g_free(nodename);
+
+    qemu_fdt_add_subnode(fdt, "/cpus");
+    qemu_fdt_setprop_cell(fdt, "/cpus", "timebase-frequency", 10000000);
+    qemu_fdt_setprop_cell(fdt, "/cpus", "#size-cells", 0x0);
+    qemu_fdt_setprop_cell(fdt, "/cpus", "#address-cells", 0x1);
+
+    for (cpu = s->soc.num_harts - 1; cpu >= 0; cpu--) {
+        nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
+        char *intc = g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        char *isa = riscv_isa_string(&s->soc.harts[cpu]);
+        qemu_fdt_add_subnode(fdt, nodename);
+        qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", 1000000000);
+        qemu_fdt_setprop_string(fdt, nodename, "mmu-type", "riscv,sv48");
+        qemu_fdt_setprop_string(fdt, nodename, "riscv,isa", isa);
+        qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv");
+        qemu_fdt_setprop_string(fdt, nodename, "status", "okay");
+        qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu);
+        qemu_fdt_setprop_string(fdt, nodename, "device_type", "cpu");
+        qemu_fdt_add_subnode(fdt, intc);
+        qemu_fdt_setprop_cell(fdt, intc, "phandle", 1);
+        qemu_fdt_setprop_cell(fdt, intc, "linux,phandle", 1);
+        qemu_fdt_setprop_string(fdt, intc, "compatible", "riscv,cpu-intc");
+        qemu_fdt_setprop(fdt, intc, "interrupt-controller", NULL, 0);
+        qemu_fdt_setprop_cell(fdt, intc, "#interrupt-cells", 1);
+        g_free(isa);
+        g_free(intc);
+        g_free(nodename);
+    }
+
+    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
+    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
+        nodename =
+            g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
+        cells[cpu * 4 + 0] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_SOFT);
+        cells[cpu * 4 + 2] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 3] = cpu_to_be32(IRQ_M_TIMER);
+        g_free(nodename);
+    }
+    nodename = g_strdup_printf("/soc/clint@%lx",
+        (long)memmap[SIFIVE_U_CLINT].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv,clint0");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[SIFIVE_U_CLINT].base,
+        0x0, memmap[SIFIVE_U_CLINT].size);
+    qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
+        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
+    g_free(cells);
+    g_free(nodename);
+
+    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
+    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
+        nodename =
+            g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
+        cells[cpu * 4 + 0] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_EXT);
+        cells[cpu * 4 + 2] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 3] = cpu_to_be32(IRQ_S_EXT);
+        g_free(nodename);
+    }
+    nodename = g_strdup_printf("/soc/interrupt-controller@%lx",
+        (long)memmap[SIFIVE_U_PLIC].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 1);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv,plic0");
+    qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0);
+    qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
+        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[SIFIVE_U_PLIC].base,
+        0x0, memmap[SIFIVE_U_PLIC].size);
+    qemu_fdt_setprop_string(fdt, nodename, "reg-names", "control");
+    qemu_fdt_setprop_cell(fdt, nodename, "riscv,max-priority", 7);
+    qemu_fdt_setprop_cell(fdt, nodename, "riscv,ndev", 4);
+    qemu_fdt_setprop_cells(fdt, nodename, "phandle", 2);
+    qemu_fdt_setprop_cells(fdt, nodename, "linux,phandle", 2);
+    plic_phandle = qemu_fdt_get_phandle(fdt, nodename);
+    g_free(cells);
+    g_free(nodename);
+
+    nodename = g_strdup_printf("/uart@%lx",
+        (long)memmap[SIFIVE_U_UART0].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "sifive,uart0");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[SIFIVE_U_UART0].base,
+        0x0, memmap[SIFIVE_U_UART0].size);
+    qemu_fdt_setprop_cells(fdt, nodename, "interrupt-parent", plic_phandle);
+    qemu_fdt_setprop_cells(fdt, nodename, "interrupts", 1);
+
+    qemu_fdt_add_subnode(fdt, "/chosen");
+    qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename);
+    qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
+    g_free(nodename);
+}
+
+static void riscv_sifive_u_init(MachineState *machine)
+{
+    const struct MemmapEntry *memmap = sifive_u_memmap;
+
+    SiFiveUState *s = g_new0(SiFiveUState, 1);
+    MemoryRegion *sys_memory = get_system_memory();
+    MemoryRegion *main_mem = g_new(MemoryRegion, 1);
+    MemoryRegion *boot_rom = g_new(MemoryRegion, 1);
+
+    /* Initialize SOC */
+    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_HART_ARRAY);
+    object_property_add_child(OBJECT(machine), "soc", OBJECT(&s->soc),
+                              &error_abort);
+    object_property_set_str(OBJECT(&s->soc), SIFIVE_U_CPU, "cpu-type",
+                            &error_abort);
+    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
+                            &error_abort);
+    object_property_set_bool(OBJECT(&s->soc), true, "realized",
+                            &error_abort);
+
+    /* register RAM */
+    memory_region_init_ram(main_mem, NULL, "riscv.sifive.u.ram",
+                           machine->ram_size, &error_fatal);
+    memory_region_add_subregion(sys_memory, memmap[SIFIVE_U_DRAM].base,
+        main_mem);
+
+    /* create device tree */
+    create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline);
+
+    /* boot rom */
+    memory_region_init_ram(boot_rom, NULL, "riscv.sifive.u.mrom",
+                           memmap[SIFIVE_U_MROM].base, &error_fatal);
+    memory_region_set_readonly(boot_rom, true);
+    memory_region_add_subregion(sys_memory, 0x0, boot_rom);
+
+    if (machine->kernel_filename) {
+        load_kernel(machine->kernel_filename);
+    }
+
+    /* reset vector */
+    uint32_t reset_vec[8] = {
+        0x00000297,                    /* 1:  auipc  t0, %pcrel_hi(dtb) */
+        0x02028593,                    /*     addi   a1, t0, %pcrel_lo(1b) */
+        0xf1402573,                    /*     csrr   a0, mhartid  */
+#if defined(TARGET_RISCV32)
+        0x0182a283,                    /*     lw     t0, 24(t0) */
+#elif defined(TARGET_RISCV64)
+        0x0182b283,                    /*     ld     t0, 24(t0) */
+#endif
+        0x00028067,                    /*     jr     t0 */
+        0x00000000,
+        memmap[SIFIVE_U_DRAM].base, /* start: .dword DRAM_BASE */
+        0x00000000,
+                                       /* dtb: */
+    };
+
+    /* copy in the reset vector */
+    copy_le32_to_phys(memmap[SIFIVE_U_MROM].base, reset_vec, sizeof(reset_vec));
+
+    /* copy in the device tree */
+    qemu_fdt_dumpdtb(s->fdt, s->fdt_size);
+    cpu_physical_memory_write(memmap[SIFIVE_U_MROM].base +
+        sizeof(reset_vec), s->fdt, s->fdt_size);
+
+    /* MMIO */
+    s->plic = sifive_plic_create(memmap[SIFIVE_U_PLIC].base,
+        (char *)SIFIVE_U_PLIC_HART_CONFIG,
+        SIFIVE_U_PLIC_NUM_SOURCES,
+        SIFIVE_U_PLIC_NUM_PRIORITIES,
+        SIFIVE_U_PLIC_PRIORITY_BASE,
+        SIFIVE_U_PLIC_PENDING_BASE,
+        SIFIVE_U_PLIC_ENABLE_BASE,
+        SIFIVE_U_PLIC_ENABLE_STRIDE,
+        SIFIVE_U_PLIC_CONTEXT_BASE,
+        SIFIVE_U_PLIC_CONTEXT_STRIDE,
+        memmap[SIFIVE_U_PLIC].size);
+    sifive_uart_create(sys_memory, memmap[SIFIVE_U_UART0].base,
+        serial_hds[0], SIFIVE_PLIC(s->plic)->irqs[SIFIVE_U_UART0_IRQ]);
+    /* sifive_uart_create(sys_memory, memmap[SIFIVE_U_UART1].base,
+        serial_hds[1], SIFIVE_PLIC(s->plic)->irqs[SIFIVE_U_UART1_IRQ]); */
+    sifive_clint_create(memmap[SIFIVE_U_CLINT].base,
+        memmap[SIFIVE_U_CLINT].size, smp_cpus,
+        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+}
+
+static int riscv_sifive_u_sysbus_device_init(SysBusDevice *sysbusdev)
+{
+    return 0;
+}
+
+static void riscv_sifive_u_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    k->init = riscv_sifive_u_sysbus_device_init;
+}
+
+static const TypeInfo riscv_sifive_u_device = {
+    .name          = TYPE_SIFIVE_U,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFiveUState),
+    .class_init    = riscv_sifive_u_class_init,
+};
+
+static void riscv_sifive_u_register_types(void)
+{
+    type_register_static(&riscv_sifive_u_device);
+}
+
+type_init(riscv_sifive_u_register_types);
+
+static void riscv_sifive_u_machine_init(MachineClass *mc)
+{
+    mc->desc = "RISC-V Board compatible with SiFive U SDK";
+    mc->init = riscv_sifive_u_init;
+    mc->max_cpus = 1;
+}
+
+DEFINE_MACHINE("sifive_u", riscv_sifive_u_machine_init)
diff --git a/hw/riscv/sifive_uart.c b/hw/riscv/sifive_uart.c
new file mode 100644
index 0000000000..b0c3798cf2
--- /dev/null
+++ b/hw/riscv/sifive_uart.c
@@ -0,0 +1,176 @@
+/*
+ * QEMU model of the UART on the SiFive E300 and U500 series SOCs.
+ *
+ * Copyright (c) 2016 Stefan O'Rear
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/sysbus.h"
+#include "chardev/char.h"
+#include "chardev/char-fe.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/sifive_uart.h"
+
+/*
+ * Not yet implemented:
+ *
+ * Transmit FIFO using "qemu/fifo8.h"
+ * SIFIVE_UART_IE_TXWM interrupts
+ * SIFIVE_UART_IE_RXWM interrupts must honor fifo watermark
+ * Rx FIFO watermark interrupt trigger threshold
+ * Tx FIFO watermark interrupt trigger threshold.
+ */
+
+static void update_irq(SiFiveUARTState *s)
+{
+    int cond = 0;
+    if ((s->ie & SIFIVE_UART_IE_RXWM) && s->rx_fifo_len) {
+        cond = 1;
+    }
+    if (cond) {
+        qemu_irq_raise(s->irq);
+    } else {
+        qemu_irq_lower(s->irq);
+    }
+}
+
+static uint64_t
+uart_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    SiFiveUARTState *s = opaque;
+    unsigned char r;
+    switch (addr) {
+    case SIFIVE_UART_RXFIFO:
+        if (s->rx_fifo_len) {
+            r = s->rx_fifo[0];
+            memmove(s->rx_fifo, s->rx_fifo + 1, s->rx_fifo_len - 1);
+            s->rx_fifo_len--;
+            qemu_chr_fe_accept_input(&s->chr);
+            update_irq(s);
+            return r;
+        }
+        return 0x80000000;
+
+    case SIFIVE_UART_TXFIFO:
+        return 0; /* Should check tx fifo */
+    case SIFIVE_UART_IE:
+        return s->ie;
+    case SIFIVE_UART_IP:
+        return s->rx_fifo_len ? SIFIVE_UART_IP_RXWM : 0;
+    case SIFIVE_UART_TXCTRL:
+        return s->txctrl;
+    case SIFIVE_UART_RXCTRL:
+        return s->rxctrl;
+    case SIFIVE_UART_DIV:
+        return s->div;
+    }
+
+    hw_error("%s: bad read: addr=0x%x\n",
+        __func__, (int)addr);
+    return 0;
+}
+
+static void
+uart_write(void *opaque, hwaddr addr,
+           uint64_t val64, unsigned int size)
+{
+    SiFiveUARTState *s = opaque;
+    uint32_t value = val64;
+    unsigned char ch = value;
+
+    switch (addr) {
+    case SIFIVE_UART_TXFIFO:
+        qemu_chr_fe_write(&s->chr, &ch, 1);
+        return;
+    case SIFIVE_UART_IE:
+        s->ie = val64;
+        update_irq(s);
+        return;
+    case SIFIVE_UART_TXCTRL:
+        s->txctrl = val64;
+        return;
+    case SIFIVE_UART_RXCTRL:
+        s->rxctrl = val64;
+        return;
+    case SIFIVE_UART_DIV:
+        s->div = val64;
+        return;
+    }
+    hw_error("%s: bad write: addr=0x%x v=0x%x\n",
+        __func__, (int)addr, (int)value);
+}
+
+static const MemoryRegionOps uart_ops = {
+    .read = uart_read,
+    .write = uart_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static void uart_rx(void *opaque, const uint8_t *buf, int size)
+{
+    SiFiveUARTState *s = opaque;
+
+    /* Got a byte.  */
+    if (s->rx_fifo_len >= sizeof(s->rx_fifo)) {
+        printf("WARNING: UART dropped char.\n");
+        return;
+    }
+    s->rx_fifo[s->rx_fifo_len++] = *buf;
+
+    update_irq(s);
+}
+
+static int uart_can_rx(void *opaque)
+{
+    SiFiveUARTState *s = opaque;
+
+    return s->rx_fifo_len < sizeof(s->rx_fifo);
+}
+
+static void uart_event(void *opaque, int event)
+{
+}
+
+static int uart_be_change(void *opaque)
+{
+    SiFiveUARTState *s = opaque;
+
+    qemu_chr_fe_set_handlers(&s->chr, uart_can_rx, uart_rx, uart_event,
+        uart_be_change, s, NULL, true);
+
+    return 0;
+}
+
+/*
+ * Create UART device.
+ */
+SiFiveUARTState *sifive_uart_create(MemoryRegion *address_space, hwaddr base,
+    Chardev *chr, qemu_irq irq)
+{
+    SiFiveUARTState *s = g_malloc0(sizeof(SiFiveUARTState));
+    s->irq = irq;
+    qemu_chr_fe_init(&s->chr, chr, &error_abort);
+    qemu_chr_fe_set_handlers(&s->chr, uart_can_rx, uart_rx, uart_event,
+        uart_be_change, s, NULL, true);
+    memory_region_init_io(&s->mmio, NULL, &uart_ops, s,
+                          TYPE_SIFIVE_UART, SIFIVE_UART_MAX);
+    memory_region_add_subregion(address_space, base, &s->mmio);
+    return s;
+}
diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c
new file mode 100644
index 0000000000..2d1f114d40
--- /dev/null
+++ b/hw/riscv/spike.c
@@ -0,0 +1,376 @@
+/*
+ * QEMU RISC-V Spike Board
+ *
+ * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
+ * Copyright (c) 2017-2018 SiFive, Inc.
+ *
+ * This provides a RISC-V Board with the following devices:
+ *
+ * 0) HTIF Console and Poweroff
+ * 1) CLINT (Timer and IPI)
+ * 2) PLIC (Platform Level Interrupt Controller)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "hw/hw.h"
+#include "hw/boards.h"
+#include "hw/loader.h"
+#include "hw/sysbus.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/riscv_htif.h"
+#include "hw/riscv/riscv_hart.h"
+#include "hw/riscv/sifive_clint.h"
+#include "hw/riscv/spike.h"
+#include "chardev/char.h"
+#include "sysemu/arch_init.h"
+#include "sysemu/device_tree.h"
+#include "exec/address-spaces.h"
+#include "elf.h"
+
+static const struct MemmapEntry {
+    hwaddr base;
+    hwaddr size;
+} spike_memmap[] = {
+    [SPIKE_MROM] =     {     0x1000,     0x2000 },
+    [SPIKE_CLINT] =    {  0x2000000,    0x10000 },
+    [SPIKE_DRAM] =     { 0x80000000,        0x0 },
+};
+
+static void copy_le32_to_phys(hwaddr pa, uint32_t *rom, size_t len)
+{
+    int i;
+    for (i = 0; i < (len >> 2); i++) {
+        stl_phys(&address_space_memory, pa + (i << 2), rom[i]);
+    }
+}
+
+static uint64_t identity_translate(void *opaque, uint64_t addr)
+{
+    return addr;
+}
+
+static uint64_t load_kernel(const char *kernel_filename)
+{
+    uint64_t kernel_entry, kernel_high;
+
+    if (load_elf_ram_sym(kernel_filename, identity_translate, NULL,
+            &kernel_entry, NULL, &kernel_high, 0, ELF_MACHINE, 1, 0,
+            NULL, true, htif_symbol_callback) < 0) {
+        error_report("qemu: could not load kernel '%s'", kernel_filename);
+        exit(1);
+    }
+    return kernel_entry;
+}
+
+static void create_fdt(SpikeState *s, const struct MemmapEntry *memmap,
+    uint64_t mem_size, const char *cmdline)
+{
+    void *fdt;
+    int cpu;
+    uint32_t *cells;
+    char *nodename;
+
+    fdt = s->fdt = create_device_tree(&s->fdt_size);
+    if (!fdt) {
+        error_report("create_device_tree() failed");
+        exit(1);
+    }
+
+    qemu_fdt_setprop_string(fdt, "/", "model", "ucbbar,spike-bare,qemu");
+    qemu_fdt_setprop_string(fdt, "/", "compatible", "ucbbar,spike-bare-dev");
+    qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2);
+    qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2);
+
+    qemu_fdt_add_subnode(fdt, "/htif");
+    qemu_fdt_setprop_string(fdt, "/htif", "compatible", "ucb,htif0");
+
+    qemu_fdt_add_subnode(fdt, "/soc");
+    qemu_fdt_setprop(fdt, "/soc", "ranges", NULL, 0);
+    qemu_fdt_setprop_string(fdt, "/soc", "compatible", "ucbbar,spike-bare-soc");
+    qemu_fdt_setprop_cell(fdt, "/soc", "#size-cells", 0x2);
+    qemu_fdt_setprop_cell(fdt, "/soc", "#address-cells", 0x2);
+
+    nodename = g_strdup_printf("/memory@%lx",
+        (long)memmap[SPIKE_DRAM].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        memmap[SPIKE_DRAM].base >> 32, memmap[SPIKE_DRAM].base,
+        mem_size >> 32, mem_size);
+    qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory");
+    g_free(nodename);
+
+    qemu_fdt_add_subnode(fdt, "/cpus");
+    qemu_fdt_setprop_cell(fdt, "/cpus", "timebase-frequency", 10000000);
+    qemu_fdt_setprop_cell(fdt, "/cpus", "#size-cells", 0x0);
+    qemu_fdt_setprop_cell(fdt, "/cpus", "#address-cells", 0x1);
+
+    for (cpu = s->soc.num_harts - 1; cpu >= 0; cpu--) {
+        nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
+        char *intc = g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        char *isa = riscv_isa_string(&s->soc.harts[cpu]);
+        qemu_fdt_add_subnode(fdt, nodename);
+        qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", 1000000000);
+        qemu_fdt_setprop_string(fdt, nodename, "mmu-type", "riscv,sv48");
+        qemu_fdt_setprop_string(fdt, nodename, "riscv,isa", isa);
+        qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv");
+        qemu_fdt_setprop_string(fdt, nodename, "status", "okay");
+        qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu);
+        qemu_fdt_setprop_string(fdt, nodename, "device_type", "cpu");
+        qemu_fdt_add_subnode(fdt, intc);
+        qemu_fdt_setprop_cell(fdt, intc, "phandle", 1);
+        qemu_fdt_setprop_cell(fdt, intc, "linux,phandle", 1);
+        qemu_fdt_setprop_string(fdt, intc, "compatible", "riscv,cpu-intc");
+        qemu_fdt_setprop(fdt, intc, "interrupt-controller", NULL, 0);
+        qemu_fdt_setprop_cell(fdt, intc, "#interrupt-cells", 1);
+        g_free(isa);
+        g_free(intc);
+        g_free(nodename);
+    }
+
+    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
+    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
+        nodename =
+            g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
+        cells[cpu * 4 + 0] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_SOFT);
+        cells[cpu * 4 + 2] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 3] = cpu_to_be32(IRQ_M_TIMER);
+        g_free(nodename);
+    }
+    nodename = g_strdup_printf("/soc/clint@%lx",
+        (long)memmap[SPIKE_CLINT].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv,clint0");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[SPIKE_CLINT].base,
+        0x0, memmap[SPIKE_CLINT].size);
+    qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
+        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
+    g_free(cells);
+    g_free(nodename);
+
+    qemu_fdt_add_subnode(fdt, "/chosen");
+    qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
+ }
+
+static void spike_v1_10_0_board_init(MachineState *machine)
+{
+    const struct MemmapEntry *memmap = spike_memmap;
+
+    SpikeState *s = g_new0(SpikeState, 1);
+    MemoryRegion *system_memory = get_system_memory();
+    MemoryRegion *main_mem = g_new(MemoryRegion, 1);
+    MemoryRegion *boot_rom = g_new(MemoryRegion, 1);
+
+    /* Initialize SOC */
+    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_HART_ARRAY);
+    object_property_add_child(OBJECT(machine), "soc", OBJECT(&s->soc),
+                              &error_abort);
+    object_property_set_str(OBJECT(&s->soc), SPIKE_V1_10_0_CPU, "cpu-type",
+                            &error_abort);
+    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
+                            &error_abort);
+    object_property_set_bool(OBJECT(&s->soc), true, "realized",
+                            &error_abort);
+
+    /* register system main memory (actual RAM) */
+    memory_region_init_ram(main_mem, NULL, "riscv.spike.ram",
+                           machine->ram_size, &error_fatal);
+    memory_region_add_subregion(system_memory, memmap[SPIKE_DRAM].base,
+        main_mem);
+
+    /* create device tree */
+    create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline);
+
+    /* boot rom */
+    memory_region_init_ram(boot_rom, NULL, "riscv.spike.bootrom",
+                           s->fdt_size + 0x2000, &error_fatal);
+    memory_region_add_subregion(system_memory, 0x0, boot_rom);
+
+    if (machine->kernel_filename) {
+        load_kernel(machine->kernel_filename);
+    }
+
+    /* reset vector */
+    uint32_t reset_vec[8] = {
+        0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(dtb) */
+        0x02028593,                  /*     addi   a1, t0, %pcrel_lo(1b) */
+        0xf1402573,                  /*     csrr   a0, mhartid  */
+#if defined(TARGET_RISCV32)
+        0x0182a283,                  /*     lw     t0, 24(t0) */
+#elif defined(TARGET_RISCV64)
+        0x0182b283,                  /*     ld     t0, 24(t0) */
+#endif
+        0x00028067,                  /*     jr     t0 */
+        0x00000000,
+        memmap[SPIKE_DRAM].base,     /* start: .dword DRAM_BASE */
+        0x00000000,
+                                     /* dtb: */
+    };
+
+    /* copy in the reset vector */
+    copy_le32_to_phys(memmap[SPIKE_MROM].base, reset_vec, sizeof(reset_vec));
+
+    /* copy in the device tree */
+    qemu_fdt_dumpdtb(s->fdt, s->fdt_size);
+    cpu_physical_memory_write(memmap[SPIKE_MROM].base + sizeof(reset_vec),
+        s->fdt, s->fdt_size);
+
+    /* initialize HTIF using symbols found in load_kernel */
+    htif_mm_init(system_memory, boot_rom, &s->soc.harts[0].env, serial_hds[0]);
+
+    /* Core Local Interruptor (timer and IPI) */
+    sifive_clint_create(memmap[SPIKE_CLINT].base, memmap[SPIKE_CLINT].size,
+        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+}
+
+static void spike_v1_09_1_board_init(MachineState *machine)
+{
+    const struct MemmapEntry *memmap = spike_memmap;
+
+    SpikeState *s = g_new0(SpikeState, 1);
+    MemoryRegion *system_memory = get_system_memory();
+    MemoryRegion *main_mem = g_new(MemoryRegion, 1);
+    MemoryRegion *boot_rom = g_new(MemoryRegion, 1);
+
+    /* Initialize SOC */
+    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_HART_ARRAY);
+    object_property_add_child(OBJECT(machine), "soc", OBJECT(&s->soc),
+                              &error_abort);
+    object_property_set_str(OBJECT(&s->soc), SPIKE_V1_09_1_CPU, "cpu-type",
+                            &error_abort);
+    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
+                            &error_abort);
+    object_property_set_bool(OBJECT(&s->soc), true, "realized",
+                            &error_abort);
+
+    /* register system main memory (actual RAM) */
+    memory_region_init_ram(main_mem, NULL, "riscv.spike.ram",
+                           machine->ram_size, &error_fatal);
+    memory_region_add_subregion(system_memory, memmap[SPIKE_DRAM].base,
+        main_mem);
+
+    /* boot rom */
+    memory_region_init_ram(boot_rom, NULL, "riscv.spike.bootrom",
+                           0x40000, &error_fatal);
+    memory_region_add_subregion(system_memory, 0x0, boot_rom);
+
+    if (machine->kernel_filename) {
+        load_kernel(machine->kernel_filename);
+    }
+
+    /* reset vector */
+    uint32_t reset_vec[8] = {
+        0x297 + memmap[SPIKE_DRAM].base - memmap[SPIKE_MROM].base, /* lui */
+        0x00028067,                   /* jump to DRAM_BASE */
+        0x00000000,                   /* reserved */
+        memmap[SPIKE_MROM].base + sizeof(reset_vec), /* config string pointer */
+        0, 0, 0, 0                    /* trap vector */
+    };
+
+    /* part one of config string - before memory size specified */
+    const char *config_string_tmpl =
+        "platform {\n"
+        "  vendor ucb;\n"
+        "  arch spike;\n"
+        "};\n"
+        "rtc {\n"
+        "  addr 0x%" PRIx64 "x;\n"
+        "};\n"
+        "ram {\n"
+        "  0 {\n"
+        "    addr 0x%" PRIx64 "x;\n"
+        "    size 0x%" PRIx64 "x;\n"
+        "  };\n"
+        "};\n"
+        "core {\n"
+        "  0" " {\n"
+        "    " "0 {\n"
+        "      isa %s;\n"
+        "      timecmp 0x%" PRIx64 "x;\n"
+        "      ipi 0x%" PRIx64 "x;\n"
+        "    };\n"
+        "  };\n"
+        "};\n";
+
+    /* build config string with supplied memory size */
+    char *isa = riscv_isa_string(&s->soc.harts[0]);
+    size_t config_string_size = strlen(config_string_tmpl) + 48;
+    char *config_string = malloc(config_string_size);
+    snprintf(config_string, config_string_size, config_string_tmpl,
+        (uint64_t)memmap[SPIKE_CLINT].base + SIFIVE_TIME_BASE,
+        (uint64_t)memmap[SPIKE_DRAM].base,
+        (uint64_t)ram_size, isa,
+        (uint64_t)memmap[SPIKE_CLINT].base + SIFIVE_TIMECMP_BASE,
+        (uint64_t)memmap[SPIKE_CLINT].base + SIFIVE_SIP_BASE);
+    g_free(isa);
+    size_t config_string_len = strlen(config_string);
+
+    /* copy in the reset vector */
+    copy_le32_to_phys(memmap[SPIKE_MROM].base, reset_vec, sizeof(reset_vec));
+
+    /* copy in the config string */
+    cpu_physical_memory_write(memmap[SPIKE_MROM].base + sizeof(reset_vec),
+        config_string, config_string_len);
+
+    /* initialize HTIF using symbols found in load_kernel */
+    htif_mm_init(system_memory, boot_rom, &s->soc.harts[0].env, serial_hds[0]);
+
+    /* Core Local Interruptor (timer and IPI) */
+    sifive_clint_create(memmap[SPIKE_CLINT].base, memmap[SPIKE_CLINT].size,
+        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+}
+
+static const TypeInfo spike_v_1_09_1_device = {
+    .name          = TYPE_RISCV_SPIKE_V1_09_1_BOARD,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SpikeState),
+};
+
+static const TypeInfo spike_v_1_10_0_device = {
+    .name          = TYPE_RISCV_SPIKE_V1_10_0_BOARD,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SpikeState),
+};
+
+static void spike_v1_09_1_machine_init(MachineClass *mc)
+{
+    mc->desc = "RISC-V Spike Board (Privileged ISA v1.9.1)";
+    mc->init = spike_v1_09_1_board_init;
+    mc->max_cpus = 1;
+}
+
+static void spike_v1_10_0_machine_init(MachineClass *mc)
+{
+    mc->desc = "RISC-V Spike Board (Privileged ISA v1.10)";
+    mc->init = spike_v1_10_0_board_init;
+    mc->max_cpus = 1;
+    mc->is_default = 1;
+}
+
+DEFINE_MACHINE("spike_v1.9.1", spike_v1_09_1_machine_init)
+DEFINE_MACHINE("spike_v1.10", spike_v1_10_0_machine_init)
+
+static void riscv_spike_board_register_types(void)
+{
+    type_register_static(&spike_v_1_09_1_device);
+    type_register_static(&spike_v_1_10_0_device);
+}
+
+type_init(riscv_spike_board_register_types);
diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
new file mode 100644
index 0000000000..e2c214e86a
--- /dev/null
+++ b/hw/riscv/virt.c
@@ -0,0 +1,420 @@
+/*
+ * QEMU RISC-V VirtIO Board
+ *
+ * Copyright (c) 2017 SiFive, Inc.
+ *
+ * RISC-V machine with 16550a UART and VirtIO MMIO
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "hw/hw.h"
+#include "hw/boards.h"
+#include "hw/loader.h"
+#include "hw/sysbus.h"
+#include "hw/char/serial.h"
+#include "target/riscv/cpu.h"
+#include "hw/riscv/riscv_htif.h"
+#include "hw/riscv/riscv_hart.h"
+#include "hw/riscv/sifive_plic.h"
+#include "hw/riscv/sifive_clint.h"
+#include "hw/riscv/sifive_test.h"
+#include "hw/riscv/virt.h"
+#include "chardev/char.h"
+#include "sysemu/arch_init.h"
+#include "sysemu/device_tree.h"
+#include "exec/address-spaces.h"
+#include "elf.h"
+
+static const struct MemmapEntry {
+    hwaddr base;
+    hwaddr size;
+} virt_memmap[] = {
+    [VIRT_DEBUG] =    {        0x0,      0x100 },
+    [VIRT_MROM] =     {     0x1000,     0x2000 },
+    [VIRT_TEST] =     {     0x4000,     0x1000 },
+    [VIRT_CLINT] =    {  0x2000000,    0x10000 },
+    [VIRT_PLIC] =     {  0xc000000,  0x4000000 },
+    [VIRT_UART0] =    { 0x10000000,      0x100 },
+    [VIRT_VIRTIO] =   { 0x10001000,     0x1000 },
+    [VIRT_DRAM] =     { 0x80000000,        0x0 },
+};
+
+static void copy_le32_to_phys(hwaddr pa, uint32_t *rom, size_t len)
+{
+    int i;
+    for (i = 0; i < (len >> 2); i++) {
+        stl_phys(&address_space_memory, pa + (i << 2), rom[i]);
+    }
+}
+
+static uint64_t identity_translate(void *opaque, uint64_t addr)
+{
+    return addr;
+}
+
+static uint64_t load_kernel(const char *kernel_filename)
+{
+    uint64_t kernel_entry, kernel_high;
+
+    if (load_elf(kernel_filename, identity_translate, NULL,
+                 &kernel_entry, NULL, &kernel_high,
+                 0, ELF_MACHINE, 1, 0) < 0) {
+        error_report("qemu: could not load kernel '%s'", kernel_filename);
+        exit(1);
+    }
+    return kernel_entry;
+}
+
+static hwaddr load_initrd(const char *filename, uint64_t mem_size,
+                          uint64_t kernel_entry, hwaddr *start)
+{
+    int size;
+
+    /* We want to put the initrd far enough into RAM that when the
+     * kernel is uncompressed it will not clobber the initrd. However
+     * on boards without much RAM we must ensure that we still leave
+     * enough room for a decent sized initrd, and on boards with large
+     * amounts of RAM we must avoid the initrd being so far up in RAM
+     * that it is outside lowmem and inaccessible to the kernel.
+     * So for boards with less  than 256MB of RAM we put the initrd
+     * halfway into RAM, and for boards with 256MB of RAM or more we put
+     * the initrd at 128MB.
+     */
+    *start = kernel_entry + MIN(mem_size / 2, 128 * 1024 * 1024);
+
+    size = load_ramdisk(filename, *start, mem_size - *start);
+    if (size == -1) {
+        size = load_image_targphys(filename, *start, mem_size - *start);
+        if (size == -1) {
+            error_report("qemu: could not load ramdisk '%s'", filename);
+            exit(1);
+        }
+    }
+    return *start + size;
+}
+
+static void *create_fdt(RISCVVirtState *s, const struct MemmapEntry *memmap,
+    uint64_t mem_size, const char *cmdline)
+{
+    void *fdt;
+    int cpu;
+    uint32_t *cells;
+    char *nodename;
+    uint32_t plic_phandle, phandle = 1;
+    int i;
+
+    fdt = s->fdt = create_device_tree(&s->fdt_size);
+    if (!fdt) {
+        error_report("create_device_tree() failed");
+        exit(1);
+    }
+
+    qemu_fdt_setprop_string(fdt, "/", "model", "riscv-virtio,qemu");
+    qemu_fdt_setprop_string(fdt, "/", "compatible", "riscv-virtio");
+    qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2);
+    qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2);
+
+    qemu_fdt_add_subnode(fdt, "/soc");
+    qemu_fdt_setprop(fdt, "/soc", "ranges", NULL, 0);
+    qemu_fdt_setprop_string(fdt, "/soc", "compatible", "riscv-virtio-soc");
+    qemu_fdt_setprop_cell(fdt, "/soc", "#size-cells", 0x2);
+    qemu_fdt_setprop_cell(fdt, "/soc", "#address-cells", 0x2);
+
+    nodename = g_strdup_printf("/memory@%lx",
+        (long)memmap[VIRT_DRAM].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        memmap[VIRT_DRAM].base >> 32, memmap[VIRT_DRAM].base,
+        mem_size >> 32, mem_size);
+    qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory");
+    g_free(nodename);
+
+    qemu_fdt_add_subnode(fdt, "/cpus");
+    qemu_fdt_setprop_cell(fdt, "/cpus", "timebase-frequency", 10000000);
+    qemu_fdt_setprop_cell(fdt, "/cpus", "#size-cells", 0x0);
+    qemu_fdt_setprop_cell(fdt, "/cpus", "#address-cells", 0x1);
+
+    for (cpu = s->soc.num_harts - 1; cpu >= 0; cpu--) {
+        int cpu_phandle = phandle++;
+        nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
+        char *intc = g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        char *isa = riscv_isa_string(&s->soc.harts[cpu]);
+        qemu_fdt_add_subnode(fdt, nodename);
+        qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", 1000000000);
+        qemu_fdt_setprop_string(fdt, nodename, "mmu-type", "riscv,sv48");
+        qemu_fdt_setprop_string(fdt, nodename, "riscv,isa", isa);
+        qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv");
+        qemu_fdt_setprop_string(fdt, nodename, "status", "okay");
+        qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu);
+        qemu_fdt_setprop_string(fdt, nodename, "device_type", "cpu");
+        qemu_fdt_add_subnode(fdt, intc);
+        qemu_fdt_setprop_cell(fdt, intc, "phandle", cpu_phandle);
+        qemu_fdt_setprop_cell(fdt, intc, "linux,phandle", cpu_phandle);
+        qemu_fdt_setprop_string(fdt, intc, "compatible", "riscv,cpu-intc");
+        qemu_fdt_setprop(fdt, intc, "interrupt-controller", NULL, 0);
+        qemu_fdt_setprop_cell(fdt, intc, "#interrupt-cells", 1);
+        g_free(isa);
+        g_free(intc);
+        g_free(nodename);
+    }
+
+    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
+    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
+        nodename =
+            g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
+        cells[cpu * 4 + 0] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_SOFT);
+        cells[cpu * 4 + 2] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 3] = cpu_to_be32(IRQ_M_TIMER);
+        g_free(nodename);
+    }
+    nodename = g_strdup_printf("/soc/clint@%lx",
+        (long)memmap[VIRT_CLINT].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv,clint0");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[VIRT_CLINT].base,
+        0x0, memmap[VIRT_CLINT].size);
+    qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
+        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
+    g_free(cells);
+    g_free(nodename);
+
+    plic_phandle = phandle++;
+    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
+    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
+        nodename =
+            g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
+        uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
+        cells[cpu * 4 + 0] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_EXT);
+        cells[cpu * 4 + 2] = cpu_to_be32(intc_phandle);
+        cells[cpu * 4 + 3] = cpu_to_be32(IRQ_S_EXT);
+        g_free(nodename);
+    }
+    nodename = g_strdup_printf("/soc/interrupt-controller@%lx",
+        (long)memmap[VIRT_PLIC].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 1);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv,plic0");
+    qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0);
+    qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
+        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[VIRT_PLIC].base,
+        0x0, memmap[VIRT_PLIC].size);
+    qemu_fdt_setprop_string(fdt, nodename, "reg-names", "control");
+    qemu_fdt_setprop_cell(fdt, nodename, "riscv,max-priority", 7);
+    qemu_fdt_setprop_cell(fdt, nodename, "riscv,ndev", VIRTIO_NDEV);
+    qemu_fdt_setprop_cells(fdt, nodename, "phandle", plic_phandle);
+    qemu_fdt_setprop_cells(fdt, nodename, "linux,phandle", plic_phandle);
+    plic_phandle = qemu_fdt_get_phandle(fdt, nodename);
+    g_free(cells);
+    g_free(nodename);
+
+    for (i = 0; i < VIRTIO_COUNT; i++) {
+        nodename = g_strdup_printf("/virtio_mmio@%lx",
+            (long)(memmap[VIRT_VIRTIO].base + i * memmap[VIRT_VIRTIO].size));
+        qemu_fdt_add_subnode(fdt, nodename);
+        qemu_fdt_setprop_string(fdt, nodename, "compatible", "virtio,mmio");
+        qemu_fdt_setprop_cells(fdt, nodename, "reg",
+            0x0, memmap[VIRT_VIRTIO].base + i * memmap[VIRT_VIRTIO].size,
+            0x0, memmap[VIRT_VIRTIO].size);
+        qemu_fdt_setprop_cells(fdt, nodename, "interrupt-parent", plic_phandle);
+        qemu_fdt_setprop_cells(fdt, nodename, "interrupts", VIRTIO_IRQ + i);
+        g_free(nodename);
+    }
+
+    nodename = g_strdup_printf("/test@%lx",
+        (long)memmap[VIRT_TEST].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "sifive,test0");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[VIRT_TEST].base,
+        0x0, memmap[VIRT_TEST].size);
+
+    nodename = g_strdup_printf("/uart@%lx",
+        (long)memmap[VIRT_UART0].base);
+    qemu_fdt_add_subnode(fdt, nodename);
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "ns16550a");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+        0x0, memmap[VIRT_UART0].base,
+        0x0, memmap[VIRT_UART0].size);
+    qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", 3686400);
+        qemu_fdt_setprop_cells(fdt, nodename, "interrupt-parent", plic_phandle);
+        qemu_fdt_setprop_cells(fdt, nodename, "interrupts", UART0_IRQ);
+
+    qemu_fdt_add_subnode(fdt, "/chosen");
+    qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename);
+    qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
+    g_free(nodename);
+
+    return fdt;
+}
+
+static void riscv_virt_board_init(MachineState *machine)
+{
+    const struct MemmapEntry *memmap = virt_memmap;
+
+    RISCVVirtState *s = g_new0(RISCVVirtState, 1);
+    MemoryRegion *system_memory = get_system_memory();
+    MemoryRegion *main_mem = g_new(MemoryRegion, 1);
+    MemoryRegion *boot_rom = g_new(MemoryRegion, 1);
+    char *plic_hart_config;
+    size_t plic_hart_config_len;
+    int i;
+    void *fdt;
+
+    /* Initialize SOC */
+    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_HART_ARRAY);
+    object_property_add_child(OBJECT(machine), "soc", OBJECT(&s->soc),
+                              &error_abort);
+    object_property_set_str(OBJECT(&s->soc), VIRT_CPU, "cpu-type",
+                            &error_abort);
+    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
+                            &error_abort);
+    object_property_set_bool(OBJECT(&s->soc), true, "realized",
+                            &error_abort);
+
+    /* register system main memory (actual RAM) */
+    memory_region_init_ram(main_mem, NULL, "riscv_virt_board.ram",
+                           machine->ram_size, &error_fatal);
+    memory_region_add_subregion(system_memory, memmap[VIRT_DRAM].base,
+        main_mem);
+
+    /* create device tree */
+    fdt = create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline);
+
+    /* boot rom */
+    memory_region_init_ram(boot_rom, NULL, "riscv_virt_board.bootrom",
+                           s->fdt_size + 0x2000, &error_fatal);
+    memory_region_add_subregion(system_memory, 0x0, boot_rom);
+
+    if (machine->kernel_filename) {
+        uint64_t kernel_entry = load_kernel(machine->kernel_filename);
+
+        if (machine->initrd_filename) {
+            hwaddr start;
+            hwaddr end = load_initrd(machine->initrd_filename,
+                                     machine->ram_size, kernel_entry,
+                                     &start);
+            qemu_fdt_setprop_cell(fdt, "/chosen",
+                                  "linux,initrd-start", start);
+            qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end",
+                                  end);
+        }
+    }
+
+    /* reset vector */
+    uint32_t reset_vec[8] = {
+        0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(dtb) */
+        0x02028593,                  /*     addi   a1, t0, %pcrel_lo(1b) */
+        0xf1402573,                  /*     csrr   a0, mhartid  */
+#if defined(TARGET_RISCV32)
+        0x0182a283,                  /*     lw     t0, 24(t0) */
+#elif defined(TARGET_RISCV64)
+        0x0182b283,                  /*     ld     t0, 24(t0) */
+#endif
+        0x00028067,                  /*     jr     t0 */
+        0x00000000,
+        memmap[VIRT_DRAM].base,      /* start: .dword memmap[VIRT_DRAM].base */
+        0x00000000,
+                                     /* dtb: */
+    };
+
+    /* copy in the reset vector */
+    copy_le32_to_phys(ROM_BASE, reset_vec, sizeof(reset_vec));
+
+    /* copy in the device tree */
+    qemu_fdt_dumpdtb(s->fdt, s->fdt_size);
+    cpu_physical_memory_write(ROM_BASE + sizeof(reset_vec),
+        s->fdt, s->fdt_size);
+
+    /* create PLIC hart topology configuration string */
+    plic_hart_config_len = (strlen(VIRT_PLIC_HART_CONFIG) + 1) * smp_cpus;
+    plic_hart_config = g_malloc0(plic_hart_config_len);
+    for (i = 0; i < smp_cpus; i++) {
+        if (i != 0) {
+            strncat(plic_hart_config, ",", plic_hart_config_len);
+        }
+        strncat(plic_hart_config, VIRT_PLIC_HART_CONFIG, plic_hart_config_len);
+        plic_hart_config_len -= (strlen(VIRT_PLIC_HART_CONFIG) + 1);
+    }
+
+    /* MMIO */
+    s->plic = sifive_plic_create(memmap[VIRT_PLIC].base,
+        plic_hart_config,
+        VIRT_PLIC_NUM_SOURCES,
+        VIRT_PLIC_NUM_PRIORITIES,
+        VIRT_PLIC_PRIORITY_BASE,
+        VIRT_PLIC_PENDING_BASE,
+        VIRT_PLIC_ENABLE_BASE,
+        VIRT_PLIC_ENABLE_STRIDE,
+        VIRT_PLIC_CONTEXT_BASE,
+        VIRT_PLIC_CONTEXT_STRIDE,
+        memmap[VIRT_PLIC].size);
+    sifive_clint_create(memmap[VIRT_CLINT].base,
+        memmap[VIRT_CLINT].size, smp_cpus,
+        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+    sifive_test_create(memmap[VIRT_TEST].base);
+
+    for (i = 0; i < VIRTIO_COUNT; i++) {
+        sysbus_create_simple("virtio-mmio",
+            memmap[VIRT_VIRTIO].base + i * memmap[VIRT_VIRTIO].size,
+            SIFIVE_PLIC(s->plic)->irqs[VIRTIO_IRQ + i]);
+    }
+
+    serial_mm_init(system_memory, memmap[VIRT_UART0].base,
+        0, SIFIVE_PLIC(s->plic)->irqs[UART0_IRQ], 399193,
+        serial_hds[0], DEVICE_LITTLE_ENDIAN);
+}
+
+static int riscv_virt_board_sysbus_device_init(SysBusDevice *sysbusdev)
+{
+    return 0;
+}
+
+static void riscv_virt_board_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    k->init = riscv_virt_board_sysbus_device_init;
+}
+
+static const TypeInfo riscv_virt_board_device = {
+    .name          = TYPE_RISCV_VIRT_BOARD,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(RISCVVirtState),
+    .class_init    = riscv_virt_board_class_init,
+};
+
+static void riscv_virt_board_machine_init(MachineClass *mc)
+{
+    mc->desc = "RISC-V VirtIO Board (Privileged spec v1.10)";
+    mc->init = riscv_virt_board_init;
+    mc->max_cpus = 8; /* hardcoded limit in BBL */
+}
+
+DEFINE_MACHINE("virt", riscv_virt_board_machine_init)
+
+static void riscv_virt_board_register_types(void)
+{
+    type_register_static(&riscv_virt_board_device);
+}
+
+type_init(riscv_virt_board_register_types);