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qemu/linux-user/main.c
bellard bc8a22cc30 better vm86 support 
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@69 c046a42c-6fe2-441c-8c8c-71466251a162
2003-03-30 21:02:40 +00:00

477 lines
15 KiB
C
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/*
* qemu main
*
* Copyright (c) 2003 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "qemu.h"
#include "cpu-i386.h"
#define DEBUG_LOGFILE "/tmp/qemu.log"
FILE *logfile = NULL;
int loglevel;
const char *interp_prefix = CONFIG_QEMU_PREFIX "/qemu-i386";
/* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
we allocate a bigger stack. Need a better solution, for example
by remapping the process stack directly at the right place */
unsigned long x86_stack_size = 512 * 1024;
unsigned long stktop;
void gemu_log(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
/***********************************************************/
/* CPUX86 core interface */
void cpu_x86_outb(int addr, int val)
{
fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
}
void cpu_x86_outw(int addr, int val)
{
fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
}
void cpu_x86_outl(int addr, int val)
{
fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
}
int cpu_x86_inb(int addr)
{
fprintf(stderr, "inb: port=0x%04x\n", addr);
return 0;
}
int cpu_x86_inw(int addr)
{
fprintf(stderr, "inw: port=0x%04x\n", addr);
return 0;
}
int cpu_x86_inl(int addr)
{
fprintf(stderr, "inl: port=0x%04x\n", addr);
return 0;
}
void write_dt(void *ptr, unsigned long addr, unsigned long limit,
int seg32_bit)
{
unsigned int e1, e2, limit_in_pages;
limit_in_pages = 0;
if (limit > 0xffff) {
limit = limit >> 12;
limit_in_pages = 1;
}
e1 = (addr << 16) | (limit & 0xffff);
e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
e2 |= limit_in_pages << 23; /* byte granularity */
e2 |= seg32_bit << 22; /* 32 bit segment */
stl((uint8_t *)ptr, e1);
stl((uint8_t *)ptr + 4, e2);
}
uint64_t gdt_table[6];
//#define DEBUG_VM86
static inline int is_revectored(int nr, struct target_revectored_struct *bitmap)
{
return (tswap32(bitmap->__map[nr >> 5]) >> (nr & 0x1f)) & 1;
}
static inline uint8_t *seg_to_linear(unsigned int seg, unsigned int reg)
{
return (uint8_t *)((seg << 4) + (reg & 0xffff));
}
static inline void pushw(CPUX86State *env, int val)
{
env->regs[R_ESP] = (env->regs[R_ESP] & ~0xffff) |
((env->regs[R_ESP] - 2) & 0xffff);
*(uint16_t *)seg_to_linear(env->segs[R_SS], env->regs[R_ESP]) = val;
}
static inline unsigned int get_vflags(CPUX86State *env)
{
unsigned int eflags;
eflags = env->eflags & ~(VM_MASK | RF_MASK | IF_MASK);
if (eflags & VIF_MASK)
eflags |= IF_MASK;
return eflags;
}
void save_v86_state(CPUX86State *env)
{
TaskState *ts = env->opaque;
#ifdef DEBUG_VM86
printf("save_v86_state\n");
#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]);
ts->target_v86->regs.eflags = tswap32(env->eflags);
/* restore 32 bit registers */
env->regs[R_EAX] = ts->vm86_saved_regs.eax;
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);
}
/* return from vm86 mode to 32 bit. The vm86() syscall will return
'retval' */
static inline void return_to_32bit(CPUX86State *env, int retval)
{
#ifdef DEBUG_VM86
printf("return_to_32bit: ret=0x%x\n", retval);
#endif
save_v86_state(env);
env->regs[R_EAX] = retval;
}
/* handle VM86 interrupt (NOTE: the CPU core currently does not
support TSS interrupt revectoring, so this code is always executed) */
static void do_int(CPUX86State *env, int intno)
{
TaskState *ts = env->opaque;
uint32_t *int_ptr, segoffs;
if (env->segs[R_CS] == TARGET_BIOSSEG)
goto cannot_handle; /* XXX: I am not sure this is really useful */
if (is_revectored(intno, &ts->target_v86->int_revectored))
goto cannot_handle;
if (intno == 0x21 && is_revectored((env->regs[R_EAX] >> 8) & 0xff,
&ts->target_v86->int21_revectored))
goto cannot_handle;
int_ptr = (uint32_t *)(intno << 2);
segoffs = tswap32(*int_ptr);
if ((segoffs >> 16) == TARGET_BIOSSEG)
goto cannot_handle;
#ifdef DEBUG_VM86
printf("VM86: emulating int 0x%x. CS:IP=%04x:%04x\n",
intno, segoffs >> 16, segoffs & 0xffff);
#endif
/* save old state */
pushw(env, get_vflags(env));
pushw(env, env->segs[R_CS]);
pushw(env, env->eip);
/* goto interrupt handler */
env->eip = segoffs & 0xffff;
cpu_x86_load_seg(env, R_CS, segoffs >> 16);
env->eflags &= ~(VIF_MASK | TF_MASK);
return;
cannot_handle:
#ifdef DEBUG_VM86
printf("VM86: return to 32 bits int 0x%x\n", intno);
#endif
return_to_32bit(env, TARGET_VM86_INTx | (intno << 8));
}
void cpu_loop(struct CPUX86State *env)
{
int trapnr;
uint8_t *pc;
target_siginfo_t info;
for(;;) {
trapnr = cpu_x86_exec(env);
pc = env->seg_cache[R_CS].base + env->eip;
switch(trapnr) {
case EXCP0D_GPF:
if (env->eflags & VM_MASK) {
#ifdef DEBUG_VM86
printf("VM86 exception %04x:%08x %02x %02x\n",
env->segs[R_CS], env->eip, pc[0], pc[1]);
#endif
/* VM86 mode */
switch(pc[0]) {
case 0xcd: /* int */
env->eip += 2;
do_int(env, pc[1]);
break;
case 0x66:
switch(pc[1]) {
case 0xfb: /* sti */
case 0x9d: /* popf */
case 0xcf: /* iret */
env->eip += 2;
return_to_32bit(env, TARGET_VM86_STI);
break;
default:
goto vm86_gpf;
}
break;
case 0xfb: /* sti */
case 0x9d: /* popf */
case 0xcf: /* iret */
env->eip++;
return_to_32bit(env, TARGET_VM86_STI);
break;
default:
vm86_gpf:
/* real VM86 GPF exception */
return_to_32bit(env, TARGET_VM86_UNKNOWN);
break;
}
} else {
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:
if (env->eflags & VM_MASK) {
do_int(env, trapnr);
} else {
/* division by zero */
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_code = TARGET_FPE_INTDIV;
info._sifields._sigfault._addr = env->eip;
queue_signal(info.si_signo, &info);
}
break;
case EXCP04_INTO:
case EXCP05_BOUND:
if (env->eflags & VM_MASK) {
do_int(env, trapnr);
} else {
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 EXCP06_ILLOP:
info.si_signo = SIGILL;
info.si_errno = 0;
info.si_code = TARGET_ILL_ILLOPN;
info._sifields._sigfault._addr = env->eip;
queue_signal(info.si_signo, &info);
break;
case EXCP_INTERRUPT:
/* just indicate that signals should be handled asap */
break;
default:
fprintf(stderr, "qemu: 0x%08lx: unhandled CPU exception 0x%x - aborting\n",
(long)pc, trapnr);
abort();
}
process_pending_signals(env);
}
}
void usage(void)
{
printf("qemu version " QEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n"
"usage: qemu [-h] [-d] [-L path] [-s size] program [arguments...]\n"
"Linux x86 emulator\n"
"\n"
"-h print this help\n"
"-d activate log (logfile=%s)\n"
"-L path set the x86 elf interpreter prefix (default=%s)\n"
"-s size set the x86 stack size in bytes (default=%ld)\n",
DEBUG_LOGFILE,
interp_prefix,
x86_stack_size);
exit(1);
}
/* 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;
if (argc <= 1)
usage();
loglevel = 0;
optind = 1;
for(;;) {
if (optind >= argc)
break;
r = argv[optind];
if (r[0] != '-')
break;
optind++;
r++;
if (!strcmp(r, "-")) {
break;
} else if (!strcmp(r, "d")) {
loglevel = 1;
} else if (!strcmp(r, "s")) {
r = argv[optind++];
x86_stack_size = strtol(r, (char **)&r, 0);
if (x86_stack_size <= 0)
usage();
if (*r == 'M')
x86_stack_size *= 1024 * 1024;
else if (*r == 'k' || *r == 'K')
x86_stack_size *= 1024;
} else if (!strcmp(r, "L")) {
interp_prefix = argv[optind++];
} else {
usage();
}
}
if (optind >= argc)
usage();
filename = argv[optind];
/* init debug */
if (loglevel) {
logfile = fopen(DEBUG_LOGFILE, "w");
if (!logfile) {
perror(DEBUG_LOGFILE);
exit(1);
}
setvbuf(logfile, NULL, _IOLBF, 0);
}
/* Zero out regs */
memset(regs, 0, sizeof(struct target_pt_regs));
/* Zero out image_info */
memset(info, 0, sizeof(struct image_info));
if(elf_exec(interp_prefix, filename, argv+optind, environ, regs, info) != 0) {
printf("Error loading %s\n", filename);
exit(1);
}
if (loglevel) {
fprintf(logfile, "start_brk 0x%08lx\n" , info->start_brk);
fprintf(logfile, "end_code 0x%08lx\n" , info->end_code);
fprintf(logfile, "start_code 0x%08lx\n" , info->start_code);
fprintf(logfile, "end_data 0x%08lx\n" , info->end_data);
fprintf(logfile, "start_stack 0x%08lx\n" , info->start_stack);
fprintf(logfile, "brk 0x%08lx\n" , info->brk);
fprintf(logfile, "esp 0x%08lx\n" , regs->esp);
fprintf(logfile, "eip 0x%08lx\n" , regs->eip);
}
target_set_brk((char *)info->brk);
syscall_init();
signal_init();
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;
env->regs[R_ECX] = regs->ecx;
env->regs[R_EDX] = regs->edx;
env->regs[R_ESI] = regs->esi;
env->regs[R_EDI] = regs->edi;
env->regs[R_EBP] = regs->ebp;
env->regs[R_ESP] = regs->esp;
env->eip = regs->eip;
/* linux segment setup */
env->gdt.base = (void *)gdt_table;
env->gdt.limit = sizeof(gdt_table) - 1;
write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1);
write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1);
cpu_x86_load_seg(env, R_CS, __USER_CS);
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_FS, __USER_DS);
cpu_x86_load_seg(env, R_GS, __USER_DS);
cpu_loop(env);
/* never exits */
return 0;
}
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