Commit 851e67a1 authored by bellard's avatar bellard
Browse files

primitive vm86 support


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@57 c046a42c-6fe2-441c-8c8c-71466251a162
parent fc2b4c48
......@@ -104,35 +104,99 @@ void write_dt(void *ptr, unsigned long addr, unsigned long limit,
uint64_t gdt_table[6];
//#define DEBUG_VM86
void cpu_loop(struct CPUX86State *env)
{
int err;
uint8_t *pc;
target_siginfo_t info;
for(;;) {
err = cpu_x86_exec(env);
pc = env->seg_cache[R_CS].base + env->eip;
switch(err) {
case EXCP0D_GPF:
if (pc[0] == 0xcd && pc[1] == 0x80) {
/* syscall */
env->eip += 2;
env->regs[R_EAX] = do_syscall(env,
env->regs[R_EAX],
env->regs[R_EBX],
env->regs[R_ECX],
env->regs[R_EDX],
env->regs[R_ESI],
env->regs[R_EDI],
env->regs[R_EBP]);
if (env->eflags & VM_MASK) {
TaskState *ts;
int ret;
#ifdef DEBUG_VM86
printf("VM86 exception %04x:%08x %02x\n",
env->segs[R_CS], env->eip, pc[0]);
#endif
/* VM86 mode */
ts = env->opaque;
/* XXX: add all cases */
switch(pc[0]) {
case 0xcd: /* int */
env->eip += 2;
ret = TARGET_VM86_INTx | (pc[1] << 8);
break;
default:
/* real VM86 GPF exception */
ret = TARGET_VM86_UNKNOWN;
break;
}
#ifdef DEBUG_VM86
printf("ret=0x%x\n", ret);
#endif
/* put the VM86 registers in the userspace register structure */
ts->target_v86->regs.eax = tswap32(env->regs[R_EAX]);
ts->target_v86->regs.ebx = tswap32(env->regs[R_EBX]);
ts->target_v86->regs.ecx = tswap32(env->regs[R_ECX]);
ts->target_v86->regs.edx = tswap32(env->regs[R_EDX]);
ts->target_v86->regs.esi = tswap32(env->regs[R_ESI]);
ts->target_v86->regs.edi = tswap32(env->regs[R_EDI]);
ts->target_v86->regs.ebp = tswap32(env->regs[R_EBP]);
ts->target_v86->regs.esp = tswap32(env->regs[R_ESP]);
ts->target_v86->regs.eip = tswap32(env->eip);
ts->target_v86->regs.cs = tswap16(env->segs[R_CS]);
ts->target_v86->regs.ss = tswap16(env->segs[R_SS]);
ts->target_v86->regs.ds = tswap16(env->segs[R_DS]);
ts->target_v86->regs.es = tswap16(env->segs[R_ES]);
ts->target_v86->regs.fs = tswap16(env->segs[R_FS]);
ts->target_v86->regs.gs = tswap16(env->segs[R_GS]);
/* restore 32 bit registers */
env->regs[R_EBX] = ts->vm86_saved_regs.ebx;
env->regs[R_ECX] = ts->vm86_saved_regs.ecx;
env->regs[R_EDX] = ts->vm86_saved_regs.edx;
env->regs[R_ESI] = ts->vm86_saved_regs.esi;
env->regs[R_EDI] = ts->vm86_saved_regs.edi;
env->regs[R_EBP] = ts->vm86_saved_regs.ebp;
env->regs[R_ESP] = ts->vm86_saved_regs.esp;
env->eflags = ts->vm86_saved_regs.eflags;
env->eip = ts->vm86_saved_regs.eip;
cpu_x86_load_seg(env, R_CS, ts->vm86_saved_regs.cs);
cpu_x86_load_seg(env, R_SS, ts->vm86_saved_regs.ss);
cpu_x86_load_seg(env, R_DS, ts->vm86_saved_regs.ds);
cpu_x86_load_seg(env, R_ES, ts->vm86_saved_regs.es);
cpu_x86_load_seg(env, R_FS, ts->vm86_saved_regs.fs);
cpu_x86_load_seg(env, R_GS, ts->vm86_saved_regs.gs);
env->regs[R_EAX] = ret;
} else {
/* XXX: more precise info */
info.si_signo = SIGSEGV;
info.si_errno = 0;
info.si_code = 0;
info._sifields._sigfault._addr = 0;
queue_signal(info.si_signo, &info);
if (pc[0] == 0xcd && pc[1] == 0x80) {
/* syscall */
env->eip += 2;
env->regs[R_EAX] = do_syscall(env,
env->regs[R_EAX],
env->regs[R_EBX],
env->regs[R_ECX],
env->regs[R_EDX],
env->regs[R_ESI],
env->regs[R_EDI],
env->regs[R_EBP]);
} else {
/* XXX: more precise info */
info.si_signo = SIGSEGV;
info.si_errno = 0;
info.si_code = 0;
info._sifields._sigfault._addr = 0;
queue_signal(info.si_signo, &info);
}
}
break;
case EXCP00_DIVZ:
......@@ -188,12 +252,15 @@ void usage(void)
/* XXX: currently only used for async signals (see signal.c) */
CPUX86State *global_env;
/* used to free thread contexts */
TaskState *first_task_state;
int main(int argc, char **argv)
{
const char *filename;
struct target_pt_regs regs1, *regs = &regs1;
struct image_info info1, *info = &info1;
TaskState ts1, *ts = &ts1;
CPUX86State *env;
int optind;
const char *r;
......@@ -272,6 +339,11 @@ int main(int argc, char **argv)
env = cpu_x86_init();
global_env = env;
/* build Task State */
memset(ts, 0, sizeof(TaskState));
env->opaque = ts;
ts->used = 1;
/* linux register setup */
env->regs[R_EAX] = regs->eax;
env->regs[R_EBX] = regs->ebx;
......
......@@ -33,6 +33,33 @@ struct image_info {
int personality;
};
/* Information about the current linux thread */
struct vm86_saved_state {
uint32_t eax; /* return code */
uint32_t ebx;
uint32_t ecx;
uint32_t edx;
uint32_t esi;
uint32_t edi;
uint32_t ebp;
uint32_t esp;
uint32_t eflags;
uint32_t eip;
uint16_t cs, ss, ds, es, fs, gs;
};
/* NOTE: we force a big alignment so that the stack stored after is
aligned too */
typedef struct TaskState {
struct TaskState *next;
struct target_vm86plus_struct *target_v86;
struct vm86_saved_state vm86_saved_regs;
int used; /* non zero if used */
uint8_t stack[0];
} __attribute__((aligned(16))) TaskState;
extern TaskState *first_task_state;
int elf_exec(const char *interp_prefix,
const char * filename, char ** argv, char ** envp,
struct target_pt_regs * regs, struct image_info *infop);
......
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