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authorKeith Packard <keithp@keithp.com>2021-01-08 22:42:52 +0000
committerAlex Bennée <alex.bennee@linaro.org>2021-01-18 10:05:06 +0000
commita10b9d93ecea0a8f01eb6de56274b1bcb101083b (patch)
tree24d8b952a691501fa22791881425539e33535d5a /hw
parent095f8c029319b79cce487e3b566cd826b93da3e6 (diff)
riscv: Add semihosting support
Adapt the arm semihosting support code for RISCV. This implementation is based on the standard for RISC-V semihosting version 0.2 as documented in https://github.com/riscv/riscv-semihosting-spec/releases/tag/0.2 Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20210107170717.2098982-6-keithp@keithp.com> Message-Id: <20210108224256.2321-17-alex.bennee@linaro.org>
Diffstat (limited to 'hw')
-rw-r--r--hw/semihosting/arm-compat-semi.c82
-rw-r--r--hw/semihosting/common-semi.h5
2 files changed, 85 insertions, 2 deletions
diff --git a/hw/semihosting/arm-compat-semi.c b/hw/semihosting/arm-compat-semi.c
index 293791f721..5fcb8663c6 100644
--- a/hw/semihosting/arm-compat-semi.c
+++ b/hw/semihosting/arm-compat-semi.c
@@ -1,6 +1,6 @@
/*
* Semihosting support for systems modeled on the Arm "Angel"
- * semihosting syscalls design.
+ * semihosting syscalls design. This includes Arm and RISC-V processors
*
* Copyright (c) 2005, 2007 CodeSourcery.
* Copyright (c) 2019 Linaro
@@ -25,6 +25,10 @@
* ARM Semihosting is documented in:
* Semihosting for AArch32 and AArch64 Release 2.0
* https://static.docs.arm.com/100863/0200/semihosting.pdf
+ *
+ * RISC-V Semihosting is documented in:
+ * RISC-V Semihosting
+ * https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
*/
#include "qemu/osdep.h"
@@ -222,6 +226,42 @@ common_semi_rambase(CPUState *cs)
#endif /* TARGET_ARM */
+#ifdef TARGET_RISCV
+static inline target_ulong
+common_semi_arg(CPUState *cs, int argno)
+{
+ RISCVCPU *cpu = RISCV_CPU(cs);
+ CPURISCVState *env = &cpu->env;
+ return env->gpr[xA0 + argno];
+}
+
+static inline void
+common_semi_set_ret(CPUState *cs, target_ulong ret)
+{
+ RISCVCPU *cpu = RISCV_CPU(cs);
+ CPURISCVState *env = &cpu->env;
+ env->gpr[xA0] = ret;
+}
+
+static inline bool
+common_semi_sys_exit_extended(CPUState *cs, int nr)
+{
+ return (nr == TARGET_SYS_EXIT_EXTENDED || sizeof(target_ulong) == 8);
+}
+
+#ifndef CONFIG_USER_ONLY
+
+static inline target_ulong
+common_semi_rambase(CPUState *cs)
+{
+ RISCVCPU *cpu = RISCV_CPU(cs);
+ CPURISCVState *env = &cpu->env;
+ return common_semi_find_region_base(env->gpr[xSP]);
+}
+#endif
+
+#endif
+
/*
* Allocate a new guest file descriptor and return it; if we
* couldn't allocate a new fd then return -1.
@@ -398,6 +438,12 @@ static target_ulong common_semi_flen_buf(CPUState *cs)
sp = env->regs[13];
}
#endif
+#ifdef TARGET_RISCV
+ RISCVCPU *cpu = RISCV_CPU(cs);
+ CPURISCVState *env = &cpu->env;
+
+ sp = env->gpr[xSP];
+#endif
return sp - 64;
}
@@ -741,6 +787,37 @@ static const GuestFDFunctions guestfd_fns[] = {
put_user_u32(val, args + (n) * 4))
#endif
+#ifdef TARGET_RISCV
+
+/*
+ * get_user_ual is defined as get_user_u32 in softmmu-semi.h,
+ * we need a macro that fetches a target_ulong
+ */
+#define get_user_utl(arg, p) \
+ ((sizeof(target_ulong) == 8) ? \
+ get_user_u64(arg, p) : \
+ get_user_u32(arg, p))
+
+/*
+ * put_user_ual is defined as put_user_u32 in softmmu-semi.h,
+ * we need a macro that stores a target_ulong
+ */
+#define put_user_utl(arg, p) \
+ ((sizeof(target_ulong) == 8) ? \
+ put_user_u64(arg, p) : \
+ put_user_u32(arg, p))
+
+#define GET_ARG(n) do { \
+ if (get_user_utl(arg ## n, args + (n) * sizeof(target_ulong))) { \
+ errno = EFAULT; \
+ return set_swi_errno(cs, -1); \
+ } \
+ } while (0)
+
+#define SET_ARG(n, val) \
+ put_user_utl(val, args + (n) * sizeof(target_ulong))
+#endif
+
/*
* Do a semihosting call.
*
@@ -1180,6 +1257,9 @@ target_ulong do_common_semihosting(CPUState *cs)
return 0;
}
#endif
+#ifdef TARGET_RISCV
+ return 0;
+#endif
/* fall through -- invalid for A32/T32 */
default:
fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
diff --git a/hw/semihosting/common-semi.h b/hw/semihosting/common-semi.h
index bc53e92c79..0bfab1c669 100644
--- a/hw/semihosting/common-semi.h
+++ b/hw/semihosting/common-semi.h
@@ -1,6 +1,6 @@
/*
* Semihosting support for systems modeled on the Arm "Angel"
- * semihosting syscalls design.
+ * semihosting syscalls design. This includes Arm and RISC-V processors
*
* Copyright (c) 2005, 2007 CodeSourcery.
* Copyright (c) 2019 Linaro
@@ -26,6 +26,9 @@
* Semihosting for AArch32 and AArch64 Release 2.0
* https://static.docs.arm.com/100863/0200/semihosting.pdf
*
+ * RISC-V Semihosting is documented in:
+ * RISC-V Semihosting
+ * https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
*/
#ifndef COMMON_SEMI_H