qemu/linux-user/riscv/cpu_loop.c
Richard Henderson ed3a06b10a semihosting: Return void from do_common_semihosting
Perform the cleanup in the FIXME comment in common_semi_gdb_syscall.
Do not modify guest registers until the syscall is complete,
which in the gdbstub case is asynchronous.

In the synchronous non-gdbstub case, use common_semi_set_ret
to set the result.  Merge set_swi_errno into common_semi_cb.
Rely on the latter for combined return value / errno setting.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 04:35:07 +05:30

117 lines
3.7 KiB
C

/*
* qemu user cpu loop
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that 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 "qemu.h"
#include "user-internals.h"
#include "cpu_loop-common.h"
#include "signal-common.h"
#include "elf.h"
#include "semihosting/common-semi.h"
void cpu_loop(CPURISCVState *env)
{
CPUState *cs = env_cpu(env);
int trapnr;
target_ulong ret;
for (;;) {
cpu_exec_start(cs);
trapnr = cpu_exec(cs);
cpu_exec_end(cs);
process_queued_cpu_work(cs);
switch (trapnr) {
case EXCP_INTERRUPT:
/* just indicate that signals should be handled asap */
break;
case EXCP_ATOMIC:
cpu_exec_step_atomic(cs);
break;
case RISCV_EXCP_U_ECALL:
env->pc += 4;
if (env->gpr[xA7] == TARGET_NR_arch_specific_syscall + 15) {
/* riscv_flush_icache_syscall is a no-op in QEMU as
self-modifying code is automatically detected */
ret = 0;
} else {
ret = do_syscall(env,
env->gpr[(env->elf_flags & EF_RISCV_RVE)
? xT0 : xA7],
env->gpr[xA0],
env->gpr[xA1],
env->gpr[xA2],
env->gpr[xA3],
env->gpr[xA4],
env->gpr[xA5],
0, 0);
}
if (ret == -QEMU_ERESTARTSYS) {
env->pc -= 4;
} else if (ret != -QEMU_ESIGRETURN) {
env->gpr[xA0] = ret;
}
if (cs->singlestep_enabled) {
goto gdbstep;
}
break;
case RISCV_EXCP_ILLEGAL_INST:
force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
break;
case RISCV_EXCP_BREAKPOINT:
case EXCP_DEBUG:
gdbstep:
force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
break;
case RISCV_EXCP_SEMIHOST:
do_common_semihosting(cs);
env->pc += 4;
break;
default:
EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
trapnr);
exit(EXIT_FAILURE);
}
process_pending_signals(env);
}
}
void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
{
CPUState *cpu = env_cpu(env);
TaskState *ts = cpu->opaque;
struct image_info *info = ts->info;
env->pc = regs->sepc;
env->gpr[xSP] = regs->sp;
env->elf_flags = info->elf_flags;
if ((env->misa_ext & RVE) && !(env->elf_flags & EF_RISCV_RVE)) {
error_report("Incompatible ELF: RVE cpu requires RVE ABI binary");
exit(EXIT_FAILURE);
}
ts->stack_base = info->start_stack;
ts->heap_base = info->brk;
/* This will be filled in on the first SYS_HEAPINFO call. */
ts->heap_limit = 0;
}