bsd-user/arm/target_arch_cpu.h: Implement system call dispatch

Implement the system call dispatch. This implements all three kinds of
system call: direct and the two indirect variants. It handles all the
special cases for thumb as well.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Kyle Evans <kevans@FreeBSD.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Warner Losh 2021-09-23 09:08:21 -06:00
parent ef1412bd84
commit 8d450c9a30

View File

@ -40,6 +40,7 @@ static inline void target_cpu_loop(CPUARMState *env)
{
int trapnr;
target_siginfo_t info;
unsigned int n;
CPUState *cs = env_cpu(env);
for (;;) {
@ -62,6 +63,99 @@ static inline void target_cpu_loop(CPUARMState *env)
/* TODO: What about instruction emulation? */
}
break;
case EXCP_SWI:
case EXCP_BKPT:
{
/*
* system call
* See arm/arm/trap.c cpu_fetch_syscall_args()
*/
if (trapnr == EXCP_BKPT) {
if (env->thumb) {
env->regs[15] += 2;
} else {
env->regs[15] += 4;
}
}
n = env->regs[7];
if (bsd_type == target_freebsd) {
int ret;
abi_ulong params = get_sp_from_cpustate(env);
int32_t syscall_nr = n;
int32_t arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8;
/* See arm/arm/trap.c cpu_fetch_syscall_args() */
if (syscall_nr == TARGET_FREEBSD_NR_syscall) {
syscall_nr = env->regs[0];
arg1 = env->regs[1];
arg2 = env->regs[2];
arg3 = env->regs[3];
get_user_s32(arg4, params);
params += sizeof(int32_t);
get_user_s32(arg5, params);
params += sizeof(int32_t);
get_user_s32(arg6, params);
params += sizeof(int32_t);
get_user_s32(arg7, params);
arg8 = 0;
} else if (syscall_nr == TARGET_FREEBSD_NR___syscall) {
syscall_nr = env->regs[0];
arg1 = env->regs[2];
arg2 = env->regs[3];
get_user_s32(arg3, params);
params += sizeof(int32_t);
get_user_s32(arg4, params);
params += sizeof(int32_t);
get_user_s32(arg5, params);
params += sizeof(int32_t);
get_user_s32(arg6, params);
arg7 = 0;
arg8 = 0;
} else {
arg1 = env->regs[0];
arg2 = env->regs[1];
arg3 = env->regs[2];
arg4 = env->regs[3];
get_user_s32(arg5, params);
params += sizeof(int32_t);
get_user_s32(arg6, params);
params += sizeof(int32_t);
get_user_s32(arg7, params);
params += sizeof(int32_t);
get_user_s32(arg8, params);
}
ret = do_freebsd_syscall(env, syscall_nr, arg1, arg2, arg3,
arg4, arg5, arg6, arg7, arg8);
/*
* Compare to arm/arm/vm_machdep.c
* cpu_set_syscall_retval()
*/
if (-TARGET_EJUSTRETURN == ret) {
/*
* Returning from a successful sigreturn syscall.
* Avoid clobbering register state.
*/
break;
}
if (-TARGET_ERESTART == ret) {
env->regs[15] -= env->thumb ? 2 : 4;
break;
}
if ((unsigned int)ret >= (unsigned int)(-515)) {
ret = -ret;
cpsr_write(env, CPSR_C, CPSR_C, CPSRWriteByInstr);
env->regs[0] = ret;
} else {
cpsr_write(env, 0, CPSR_C, CPSRWriteByInstr);
env->regs[0] = ret; /* XXX need to handle lseek()? */
/* env->regs[1] = 0; */
}
} else {
fprintf(stderr, "qemu: bsd_type (= %d) syscall "
"not supported\n", bsd_type);
}
}
break;
case EXCP_INTERRUPT:
/* just indicate that signals should be handled asap */
break;