hw: add OpenCores 10/100 Mbps Ethernet controller

This is OpenCores Ethernet MAC + subset of National Semiconductors
DP83838C PHY.
OpenCores Ethernet MAC project: http://opencores.org/project,ethmac

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 728 insertions, 0 deletions

diff --git a/hw/opencores_eth.c b/hw/opencores_eth.c
new file mode 100644
index 0000000000..64b616ec1c
--- /dev/null
+++ b/hw/opencores_eth.c
@@ -0,0 +1,728 @@
+/*
+ * OpenCores Ethernet MAC 10/100 + subset of
+ * National Semiconductors DP83848C 10/100 PHY
+ *
+ * http://opencores.org/svnget,ethmac?file=%2Ftrunk%2F%2Fdoc%2Feth_speci.pdf
+ * http://cache.national.com/ds/DP/DP83848C.pdf
+ *
+ * Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the Open Source and Linux Lab nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "hw.h"
+#include "sysbus.h"
+#include "net.h"
+#include "sysemu.h"
+#include "trace.h"
+
+/* RECSMALL is not used because it breaks tap networking in linux:
+ * incoming ARP responses are too short
+ */
+#undef USE_RECSMALL
+
+#define GET_FIELD(v, field) (((v) & (field)) >> (field ## _LBN))
+#define GET_REGBIT(s, reg, field) ((s)->regs[reg] & (reg ## _ ## field))
+#define GET_REGFIELD(s, reg, field) \
+    GET_FIELD((s)->regs[reg], reg ## _ ## field)
+
+#define SET_FIELD(v, field, data) \
+    ((v) = (((v) & ~(field)) | (((data) << (field ## _LBN)) & (field))))
+#define SET_REGFIELD(s, reg, field, data) \
+    SET_FIELD((s)->regs[reg], reg ## _ ## field, data)
+
+/* PHY MII registers */
+enum {
+    MII_BMCR,
+    MII_BMSR,
+    MII_PHYIDR1,
+    MII_PHYIDR2,
+    MII_ANAR,
+    MII_ANLPAR,
+    MII_REG_MAX = 16,
+};
+
+typedef struct Mii {
+    uint16_t regs[MII_REG_MAX];
+    bool link_ok;
+} Mii;
+
+static void mii_set_link(Mii *s, bool link_ok)
+{
+    if (link_ok) {
+        s->regs[MII_BMSR] |= 0x4;
+        s->regs[MII_ANLPAR] |= 0x01e1;
+    } else {
+        s->regs[MII_BMSR] &= ~0x4;
+        s->regs[MII_ANLPAR] &= 0x01ff;
+    }
+    s->link_ok = link_ok;
+}
+
+static void mii_reset(Mii *s)
+{
+    memset(s->regs, 0, sizeof(s->regs));
+    s->regs[MII_BMCR] = 0x1000;
+    s->regs[MII_BMSR] = 0x7848; /* no ext regs */
+    s->regs[MII_PHYIDR1] = 0x2000;
+    s->regs[MII_PHYIDR2] = 0x5c90;
+    s->regs[MII_ANAR] = 0x01e1;
+    mii_set_link(s, s->link_ok);
+}
+
+static void mii_ro(Mii *s, uint16_t v)
+{
+}
+
+static void mii_write_bmcr(Mii *s, uint16_t v)
+{
+    if (v & 0x8000) {
+        mii_reset(s);
+    } else {
+        s->regs[MII_BMCR] = v;
+    }
+}
+
+static void mii_write_host(Mii *s, unsigned idx, uint16_t v)
+{
+    static void (*reg_write[MII_REG_MAX])(Mii *s, uint16_t v) = {
+        [MII_BMCR] = mii_write_bmcr,
+        [MII_BMSR] = mii_ro,
+        [MII_PHYIDR1] = mii_ro,
+        [MII_PHYIDR2] = mii_ro,
+    };
+
+    if (idx < MII_REG_MAX) {
+        trace_open_eth_mii_write(idx, v);
+        if (reg_write[idx]) {
+            reg_write[idx](s, v);
+        } else {
+            s->regs[idx] = v;
+        }
+    }
+}
+
+static uint16_t mii_read_host(Mii *s, unsigned idx)
+{
+    trace_open_eth_mii_read(idx, s->regs[idx]);
+    return s->regs[idx];
+}
+
+/* OpenCores Ethernet registers */
+enum {
+    MODER,
+    INT_SOURCE,
+    INT_MASK,
+    IPGT,
+    IPGR1,
+    IPGR2,
+    PACKETLEN,
+    COLLCONF,
+    TX_BD_NUM,
+    CTRLMODER,
+    MIIMODER,
+    MIICOMMAND,
+    MIIADDRESS,
+    MIITX_DATA,
+    MIIRX_DATA,
+    MIISTATUS,
+    MAC_ADDR0,
+    MAC_ADDR1,
+    HASH0,
+    HASH1,
+    TXCTRL,
+    REG_MAX,
+};
+
+enum {
+    MODER_RECSMALL = 0x10000,
+    MODER_PAD = 0x8000,
+    MODER_HUGEN = 0x4000,
+    MODER_RST = 0x800,
+    MODER_LOOPBCK = 0x80,
+    MODER_PRO = 0x20,
+    MODER_IAM = 0x10,
+    MODER_BRO = 0x8,
+    MODER_TXEN = 0x2,
+    MODER_RXEN = 0x1,
+};
+
+enum {
+    INT_SOURCE_RXB = 0x4,
+    INT_SOURCE_TXB = 0x1,
+};
+
+enum {
+    PACKETLEN_MINFL = 0xffff0000,
+    PACKETLEN_MINFL_LBN = 16,
+    PACKETLEN_MAXFL = 0xffff,
+    PACKETLEN_MAXFL_LBN = 0,
+};
+
+enum {
+    MIICOMMAND_WCTRLDATA = 0x4,
+    MIICOMMAND_RSTAT = 0x2,
+    MIICOMMAND_SCANSTAT = 0x1,
+};
+
+enum {
+    MIIADDRESS_RGAD = 0x1f00,
+    MIIADDRESS_RGAD_LBN = 8,
+    MIIADDRESS_FIAD = 0x1f,
+    MIIADDRESS_FIAD_LBN = 0,
+};
+
+enum {
+    MIITX_DATA_CTRLDATA = 0xffff,
+    MIITX_DATA_CTRLDATA_LBN = 0,
+};
+
+enum {
+    MIIRX_DATA_PRSD = 0xffff,
+    MIIRX_DATA_PRSD_LBN = 0,
+};
+
+enum {
+    MIISTATUS_LINKFAIL = 0x1,
+    MIISTATUS_LINKFAIL_LBN = 0,
+};
+
+enum {
+    MAC_ADDR0_BYTE2 = 0xff000000,
+    MAC_ADDR0_BYTE2_LBN = 24,
+    MAC_ADDR0_BYTE3 = 0xff0000,
+    MAC_ADDR0_BYTE3_LBN = 16,
+    MAC_ADDR0_BYTE4 = 0xff00,
+    MAC_ADDR0_BYTE4_LBN = 8,
+    MAC_ADDR0_BYTE5 = 0xff,
+    MAC_ADDR0_BYTE5_LBN = 0,
+};
+
+enum {
+    MAC_ADDR1_BYTE0 = 0xff00,
+    MAC_ADDR1_BYTE0_LBN = 8,
+    MAC_ADDR1_BYTE1 = 0xff,
+    MAC_ADDR1_BYTE1_LBN = 0,
+};
+
+enum {
+    TXD_LEN = 0xffff0000,
+    TXD_LEN_LBN = 16,
+    TXD_RD = 0x8000,
+    TXD_IRQ = 0x4000,
+    TXD_WR = 0x2000,
+    TXD_PAD = 0x1000,
+    TXD_CRC = 0x800,
+    TXD_UR = 0x100,
+    TXD_RTRY = 0xf0,
+    TXD_RTRY_LBN = 4,
+    TXD_RL = 0x8,
+    TXD_LC = 0x4,
+    TXD_DF = 0x2,
+    TXD_CS = 0x1,
+};
+
+enum {
+    RXD_LEN = 0xffff0000,
+    RXD_LEN_LBN = 16,
+    RXD_E = 0x8000,
+    RXD_IRQ = 0x4000,
+    RXD_WRAP = 0x2000,
+    RXD_CF = 0x100,
+    RXD_M = 0x80,
+    RXD_OR = 0x40,
+    RXD_IS = 0x20,
+    RXD_DN = 0x10,
+    RXD_TL = 0x8,
+    RXD_SF = 0x4,
+    RXD_CRC = 0x2,
+    RXD_LC = 0x1,
+};
+
+typedef struct desc {
+    uint32_t len_flags;
+    uint32_t buf_ptr;
+} desc;
+
+#define DEFAULT_PHY 1
+
+typedef struct OpenEthState {
+    SysBusDevice dev;
+    NICState *nic;
+    NICConf conf;
+    MemoryRegion reg_io;
+    MemoryRegion desc_io;
+    qemu_irq irq;
+
+    Mii mii;
+    uint32_t regs[REG_MAX];
+    unsigned tx_desc;
+    unsigned rx_desc;
+    desc desc[128];
+} OpenEthState;
+
+static desc *rx_desc(OpenEthState *s)
+{
+    return s->desc + s->rx_desc;
+}
+
+static desc *tx_desc(OpenEthState *s)
+{
+    return s->desc + s->tx_desc;
+}
+
+static void open_eth_update_irq(OpenEthState *s,
+        uint32_t old, uint32_t new)
+{
+    if (!old != !new) {
+        trace_open_eth_update_irq(new);
+        qemu_set_irq(s->irq, new);
+    }
+}
+
+static void open_eth_int_source_write(OpenEthState *s,
+        uint32_t val)
+{
+    uint32_t old_val = s->regs[INT_SOURCE];
+
+    s->regs[INT_SOURCE] = val;
+    open_eth_update_irq(s, old_val & s->regs[INT_MASK],
+            s->regs[INT_SOURCE] & s->regs[INT_MASK]);
+}
+
+static void open_eth_set_link_status(VLANClientState *nc)
+{
+    OpenEthState *s = DO_UPCAST(NICState, nc, nc)->opaque;
+
+    if (GET_REGBIT(s, MIICOMMAND, SCANSTAT)) {
+        SET_REGFIELD(s, MIISTATUS, LINKFAIL, nc->link_down);
+    }
+    mii_set_link(&s->mii, !nc->link_down);
+}
+
+static void open_eth_reset(void *opaque)
+{
+    OpenEthState *s = opaque;
+
+    memset(s->regs, 0, sizeof(s->regs));
+    s->regs[MODER] = 0xa000;
+    s->regs[IPGT] = 0x12;
+    s->regs[IPGR1] = 0xc;
+    s->regs[IPGR2] = 0x12;
+    s->regs[PACKETLEN] = 0x400600;
+    s->regs[COLLCONF] = 0xf003f;
+    s->regs[TX_BD_NUM] = 0x40;
+    s->regs[MIIMODER] = 0x64;
+
+    s->tx_desc = 0;
+    s->rx_desc = 0x40;
+
+    mii_reset(&s->mii);
+    open_eth_set_link_status(&s->nic->nc);
+}
+
+static int open_eth_can_receive(VLANClientState *nc)
+{
+    OpenEthState *s = DO_UPCAST(NICState, nc, nc)->opaque;
+
+    return GET_REGBIT(s, MODER, RXEN) &&
+        (s->regs[TX_BD_NUM] < 0x80) &&
+        (rx_desc(s)->len_flags & RXD_E);
+}
+
+#define POLYNOMIAL 0x04c11db6
+
+/* From FreeBSD */
+/* XXX: optimize */
+static unsigned compute_mcast_idx(const uint8_t *ep)
+{
+    uint32_t crc;
+    int carry, i, j;
+    uint8_t b;
+
+    crc = 0xffffffff;
+    for (i = 0; i < 6; i++) {
+        b = *ep++;
+        for (j = 0; j < 8; j++) {
+            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
+            crc <<= 1;
+            b >>= 1;
+            if (carry) {
+                crc = ((crc ^ POLYNOMIAL) | carry);
+            }
+        }
+    }
+    return crc >> 26;
+}
+
+static ssize_t open_eth_receive(VLANClientState *nc,
+        const uint8_t *buf, size_t size)
+{
+    OpenEthState *s = DO_UPCAST(NICState, nc, nc)->opaque;
+    size_t maxfl = GET_REGFIELD(s, PACKETLEN, MAXFL);
+    size_t minfl = GET_REGFIELD(s, PACKETLEN, MINFL);
+    bool miss = true;
+
+    trace_open_eth_receive((unsigned)size);
+
+    if (size >= 6) {
+        static const uint8_t bcast_addr[] = {
+            0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+        };
+        if (memcmp(buf, bcast_addr, sizeof(bcast_addr)) == 0) {
+            miss = GET_REGBIT(s, MODER, BRO);
+        } else if ((buf[0] & 0x1) || GET_REGBIT(s, MODER, IAM)) {
+            unsigned mcast_idx = compute_mcast_idx(buf);
+            miss = !(s->regs[HASH0 + mcast_idx / 32] &
+                    (1 << (mcast_idx % 32)));
+            trace_open_eth_receive_mcast(
+                    mcast_idx, s->regs[HASH0], s->regs[HASH1]);
+        } else {
+            miss = GET_REGFIELD(s, MAC_ADDR1, BYTE0) != buf[0] ||
+                GET_REGFIELD(s, MAC_ADDR1, BYTE1) != buf[1] ||
+                GET_REGFIELD(s, MAC_ADDR0, BYTE2) != buf[2] ||
+                GET_REGFIELD(s, MAC_ADDR0, BYTE3) != buf[3] ||
+                GET_REGFIELD(s, MAC_ADDR0, BYTE4) != buf[4] ||
+                GET_REGFIELD(s, MAC_ADDR0, BYTE5) != buf[5];
+        }
+    }
+
+    if (miss && !GET_REGBIT(s, MODER, PRO)) {
+        trace_open_eth_receive_reject();
+        return size;
+    }
+
+#ifdef USE_RECSMALL
+    if (GET_REGBIT(s, MODER, RECSMALL) || size >= minfl) {
+#else
+    {
+#endif
+        desc *desc = rx_desc(s);
+        size_t copy_size = GET_REGBIT(s, MODER, HUGEN) ? 65536 : maxfl;
+
+        desc->len_flags &= ~(RXD_CF | RXD_M | RXD_OR |
+                RXD_IS | RXD_DN | RXD_TL | RXD_SF | RXD_CRC | RXD_LC);
+
+        if (copy_size > size) {
+            copy_size = size;
+        }
+        if (miss) {
+            desc->len_flags |= RXD_M;
+        }
+        if (size > maxfl) {
+            desc->len_flags |= RXD_TL;
+        }
+#ifdef USE_RECSMALL
+        if (size < minfl) {
+            desc->len_flags |= RXD_SF;
+        }
+#endif
+
+        cpu_physical_memory_write(desc->buf_ptr, buf, copy_size);
+
+        if (GET_REGBIT(s, MODER, PAD) && copy_size < minfl) {
+            static const uint8_t zero[65536] = {0};
+
+            cpu_physical_memory_write(desc->buf_ptr + copy_size,
+                    zero, minfl - copy_size);
+            copy_size = minfl;
+        }
+
+        SET_FIELD(desc->len_flags, RXD_LEN, copy_size);
+
+        if ((desc->len_flags & RXD_WRAP) || s->rx_desc == 0x7f) {
+            s->rx_desc = s->regs[TX_BD_NUM];
+        } else {
+            ++s->rx_desc;
+        }
+        desc->len_flags &= ~RXD_E;
+
+        trace_open_eth_receive_desc(desc->buf_ptr, desc->len_flags);
+
+        if (desc->len_flags & RXD_IRQ) {
+            open_eth_int_source_write(s,
+                    s->regs[INT_SOURCE] | INT_SOURCE_RXB);
+        }
+    }
+    return size;
+}
+
+static void open_eth_cleanup(VLANClientState *nc)
+{
+}
+
+static NetClientInfo net_open_eth_info = {
+    .type = NET_CLIENT_TYPE_NIC,
+    .size = sizeof(NICState),
+    .can_receive = open_eth_can_receive,
+    .receive = open_eth_receive,
+    .cleanup = open_eth_cleanup,
+    .link_status_changed = open_eth_set_link_status,
+};
+
+static void open_eth_start_xmit(OpenEthState *s, desc *tx)
+{
+    uint8_t buf[65536];
+    unsigned len = GET_FIELD(tx->len_flags, TXD_LEN);
+    unsigned tx_len = len;
+
+    if ((tx->len_flags & TXD_PAD) &&
+            tx_len < GET_REGFIELD(s, PACKETLEN, MINFL)) {
+        tx_len = GET_REGFIELD(s, PACKETLEN, MINFL);
+    }
+    if (!GET_REGBIT(s, MODER, HUGEN) &&
+            tx_len > GET_REGFIELD(s, PACKETLEN, MAXFL)) {
+        tx_len = GET_REGFIELD(s, PACKETLEN, MAXFL);
+    }
+
+    trace_open_eth_start_xmit(tx->buf_ptr, len, tx_len);
+
+    if (len > tx_len) {
+        len = tx_len;
+    }
+    cpu_physical_memory_read(tx->buf_ptr, buf, len);
+    if (tx_len > len) {
+        memset(buf + len, 0, tx_len - len);
+    }
+    qemu_send_packet(&s->nic->nc, buf, tx_len);
+
+    if (tx->len_flags & TXD_WR) {
+        s->tx_desc = 0;
+    } else {
+        ++s->tx_desc;
+        if (s->tx_desc >= s->regs[TX_BD_NUM]) {
+            s->tx_desc = 0;
+        }
+    }
+    tx->len_flags &= ~(TXD_RD | TXD_UR |
+            TXD_RTRY | TXD_RL | TXD_LC | TXD_DF | TXD_CS);
+    if (tx->len_flags & TXD_IRQ) {
+        open_eth_int_source_write(s, s->regs[INT_SOURCE] | INT_SOURCE_TXB);
+    }
+
+}
+
+static void open_eth_check_start_xmit(OpenEthState *s)
+{
+    desc *tx = tx_desc(s);
+    if (GET_REGBIT(s, MODER, TXEN) && s->regs[TX_BD_NUM] > 0 &&
+            (tx->len_flags & TXD_RD) &&
+            GET_FIELD(tx->len_flags, TXD_LEN) > 4) {
+        open_eth_start_xmit(s, tx);
+    }
+}
+
+static uint64_t open_eth_reg_read(void *opaque,
+        target_phys_addr_t addr, unsigned int size)
+{
+    static uint32_t (*reg_read[REG_MAX])(OpenEthState *s) = {
+    };
+    OpenEthState *s = opaque;
+    unsigned idx = addr / 4;
+    uint64_t v = 0;
+
+    if (idx < REG_MAX) {
+        if (reg_read[idx]) {
+            v = reg_read[idx](s);
+        } else {
+            v = s->regs[idx];
+        }
+    }
+    trace_open_eth_reg_read((uint32_t)addr, (uint32_t)v);
+    return v;
+}
+
+static void open_eth_ro(OpenEthState *s, uint32_t val)
+{
+}
+
+static void open_eth_moder_host_write(OpenEthState *s, uint32_t val)
+{
+    uint32_t set = val & ~s->regs[MODER];
+
+    if (set & MODER_RST) {
+        open_eth_reset(s);
+    }
+
+    s->regs[MODER] = val;
+
+    if (set & MODER_RXEN) {
+        s->rx_desc = s->regs[TX_BD_NUM];
+    }
+    if (set & MODER_TXEN) {
+        s->tx_desc = 0;
+        open_eth_check_start_xmit(s);
+    }
+}
+
+static void open_eth_int_source_host_write(OpenEthState *s, uint32_t val)
+{
+    uint32_t old = s->regs[INT_SOURCE];
+
+    s->regs[INT_SOURCE] &= ~val;
+    open_eth_update_irq(s, old & s->regs[INT_MASK],
+            s->regs[INT_SOURCE] & s->regs[INT_MASK]);
+}
+
+static void open_eth_int_mask_host_write(OpenEthState *s, uint32_t val)
+{
+    uint32_t old = s->regs[INT_MASK];
+
+    s->regs[INT_MASK] = val;
+    open_eth_update_irq(s, s->regs[INT_SOURCE] & old,
+            s->regs[INT_SOURCE] & s->regs[INT_MASK]);
+}
+
+static void open_eth_mii_command_host_write(OpenEthState *s, uint32_t val)
+{
+    unsigned fiad = GET_REGFIELD(s, MIIADDRESS, FIAD);
+    unsigned rgad = GET_REGFIELD(s, MIIADDRESS, RGAD);
+
+    if (val & MIICOMMAND_WCTRLDATA) {
+        if (fiad == DEFAULT_PHY) {
+            mii_write_host(&s->mii, rgad,
+                    GET_REGFIELD(s, MIITX_DATA, CTRLDATA));
+        }
+    }
+    if (val & MIICOMMAND_RSTAT) {
+        if (fiad == DEFAULT_PHY) {
+            SET_REGFIELD(s, MIIRX_DATA, PRSD,
+                    mii_read_host(&s->mii, rgad));
+        } else {
+            s->regs[MIIRX_DATA] = 0xffff;
+        }
+        SET_REGFIELD(s, MIISTATUS, LINKFAIL, s->nic->nc.link_down);
+    }
+}
+
+static void open_eth_mii_tx_host_write(OpenEthState *s, uint32_t val)
+{
+    SET_REGFIELD(s, MIITX_DATA, CTRLDATA, val);
+    if (GET_REGFIELD(s, MIIADDRESS, FIAD) == DEFAULT_PHY) {
+        mii_write_host(&s->mii, GET_REGFIELD(s, MIIADDRESS, RGAD),
+                GET_REGFIELD(s, MIITX_DATA, CTRLDATA));
+    }
+}
+
+static void open_eth_reg_write(void *opaque,
+        target_phys_addr_t addr, uint64_t val, unsigned int size)
+{
+    static void (*reg_write[REG_MAX])(OpenEthState *s, uint32_t val) = {
+        [MODER] = open_eth_moder_host_write,
+        [INT_SOURCE] = open_eth_int_source_host_write,
+        [INT_MASK] = open_eth_int_mask_host_write,
+        [MIICOMMAND] = open_eth_mii_command_host_write,
+        [MIITX_DATA] = open_eth_mii_tx_host_write,
+        [MIISTATUS] = open_eth_ro,
+    };
+    OpenEthState *s = opaque;
+    unsigned idx = addr / 4;
+
+    if (idx < REG_MAX) {
+        trace_open_eth_reg_write((uint32_t)addr, (uint32_t)val);
+        if (reg_write[idx]) {
+            reg_write[idx](s, val);
+        } else {
+            s->regs[idx] = val;
+        }
+    }
+}
+
+static uint64_t open_eth_desc_read(void *opaque,
+        target_phys_addr_t addr, unsigned int size)
+{
+    OpenEthState *s = opaque;
+    uint64_t v = 0;
+
+    addr &= 0x3ff;
+    memcpy(&v, (uint8_t *)s->desc + addr, size);
+    trace_open_eth_desc_read((uint32_t)addr, (uint32_t)v);
+    return v;
+}
+
+static void open_eth_desc_write(void *opaque,
+        target_phys_addr_t addr, uint64_t val, unsigned int size)
+{
+    OpenEthState *s = opaque;
+
+    addr &= 0x3ff;
+    trace_open_eth_desc_write((uint32_t)addr, (uint32_t)val);
+    memcpy((uint8_t *)s->desc + addr, &val, size);
+    open_eth_check_start_xmit(s);
+}
+
+
+static MemoryRegionOps open_eth_reg_ops = {
+    .read = open_eth_reg_read,
+    .write = open_eth_reg_write,
+};
+
+static MemoryRegionOps open_eth_desc_ops = {
+    .read = open_eth_desc_read,
+    .write = open_eth_desc_write,
+};
+
+static int sysbus_open_eth_init(SysBusDevice *dev)
+{
+    OpenEthState *s = DO_UPCAST(OpenEthState, dev, dev);
+
+    memory_region_init_io(&s->reg_io, &open_eth_reg_ops, s,
+            "open_eth.regs", 0x54);
+    sysbus_init_mmio_region(dev, &s->reg_io);
+
+    memory_region_init_io(&s->desc_io, &open_eth_desc_ops, s,
+            "open_eth.desc", 0x400);
+    sysbus_init_mmio_region(dev, &s->desc_io);
+
+    sysbus_init_irq(dev, &s->irq);
+
+    s->nic = qemu_new_nic(&net_open_eth_info, &s->conf,
+                          s->dev.qdev.info->name, s->dev.qdev.id, s);
+    return 0;
+}
+
+static void qdev_open_eth_reset(DeviceState *dev)
+{
+    OpenEthState *d = DO_UPCAST(OpenEthState, dev.qdev, dev);
+    open_eth_reset(d);
+}
+
+static SysBusDeviceInfo open_eth_info = {
+    .qdev.name  = "open_eth",
+    .qdev.desc  = "Opencores 10/100 Mbit Ethernet",
+    .qdev.size  = sizeof(OpenEthState),
+    .qdev.reset = qdev_open_eth_reset,
+    .init       = sysbus_open_eth_init,
+    .qdev.props = (Property[]) {
+        DEFINE_NIC_PROPERTIES(OpenEthState, conf),
+        DEFINE_PROP_END_OF_LIST(),
+    }
+};
+
+static void open_eth_register_devices(void)
+{
+    sysbus_register_withprop(&open_eth_info);
+}
+
+device_init(open_eth_register_devices)