diff options
Diffstat (limited to 'qemu/tests/tcg/runcom.c')
| -rw-r--r-- | qemu/tests/tcg/runcom.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/qemu/tests/tcg/runcom.c b/qemu/tests/tcg/runcom.c new file mode 100644 index 000000000..d60342bfc --- /dev/null +++ b/qemu/tests/tcg/runcom.c @@ -0,0 +1,192 @@ +/* + * Simple example of use of vm86: launch a basic .com DOS executable + */ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <inttypes.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <signal.h> + +#include <linux/unistd.h> +#include <asm/vm86.h> + +extern int vm86 (unsigned long int subfunction, + struct vm86plus_struct *info); + +#define VIF_MASK 0x00080000 + +//#define SIGTEST + +#define COM_BASE_ADDR 0x10100 + +static void usage(void) +{ + printf("runcom version 0.1 (c) 2003 Fabrice Bellard\n" + "usage: runcom file.com\n" + "VM86 Run simple .com DOS executables (linux vm86 test mode)\n"); + exit(1); +} + +static inline void set_bit(uint8_t *a, unsigned int bit) +{ + a[bit / 8] |= (1 << (bit % 8)); +} + +static inline uint8_t *seg_to_linear(unsigned int seg, unsigned int reg) +{ + return (uint8_t *)((seg << 4) + (reg & 0xffff)); +} + +static inline void pushw(struct vm86_regs *r, int val) +{ + r->esp = (r->esp & ~0xffff) | ((r->esp - 2) & 0xffff); + *(uint16_t *)seg_to_linear(r->ss, r->esp) = val; +} + +void dump_regs(struct vm86_regs *r) +{ + fprintf(stderr, + "EAX=%08lx EBX=%08lx ECX=%08lx EDX=%08lx\n" + "ESI=%08lx EDI=%08lx EBP=%08lx ESP=%08lx\n" + "EIP=%08lx EFL=%08lx\n" + "CS=%04x DS=%04x ES=%04x SS=%04x FS=%04x GS=%04x\n", + r->eax, r->ebx, r->ecx, r->edx, r->esi, r->edi, r->ebp, r->esp, + r->eip, r->eflags, + r->cs, r->ds, r->es, r->ss, r->fs, r->gs); +} + +#ifdef SIGTEST +void alarm_handler(int sig) +{ + fprintf(stderr, "alarm signal=%d\n", sig); + alarm(1); +} +#endif + +int main(int argc, char **argv) +{ + uint8_t *vm86_mem; + const char *filename; + int fd, ret, seg; + struct vm86plus_struct ctx; + struct vm86_regs *r; + + if (argc != 2) + usage(); + filename = argv[1]; + + vm86_mem = mmap((void *)0x00000000, 0x110000, + PROT_WRITE | PROT_READ | PROT_EXEC, + MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0); + if (vm86_mem == MAP_FAILED) { + perror("mmap"); + exit(1); + } +#ifdef SIGTEST + { + struct sigaction act; + + act.sa_handler = alarm_handler; + sigemptyset(&act.sa_mask); + act.sa_flags = 0; + sigaction(SIGALRM, &act, NULL); + alarm(1); + } +#endif + + /* load the MSDOS .com executable */ + fd = open(filename, O_RDONLY); + if (fd < 0) { + perror(filename); + exit(1); + } + ret = read(fd, vm86_mem + COM_BASE_ADDR, 65536 - 256); + if (ret < 0) { + perror("read"); + exit(1); + } + close(fd); + + memset(&ctx, 0, sizeof(ctx)); + /* init basic registers */ + r = &ctx.regs; + r->eip = 0x100; + r->esp = 0xfffe; + seg = (COM_BASE_ADDR - 0x100) >> 4; + r->cs = seg; + r->ss = seg; + r->ds = seg; + r->es = seg; + r->fs = seg; + r->gs = seg; + r->eflags = VIF_MASK; + + /* put return code */ + set_bit((uint8_t *)&ctx.int_revectored, 0x21); + *seg_to_linear(r->cs, 0) = 0xb4; /* mov ah, $0 */ + *seg_to_linear(r->cs, 1) = 0x00; + *seg_to_linear(r->cs, 2) = 0xcd; /* int $0x21 */ + *seg_to_linear(r->cs, 3) = 0x21; + pushw(&ctx.regs, 0x0000); + + /* the value of these registers seem to be assumed by pi_10.com */ + r->esi = 0x100; + r->ecx = 0xff; + r->ebp = 0x0900; + r->edi = 0xfffe; + + for(;;) { + ret = vm86(VM86_ENTER, &ctx); + switch(VM86_TYPE(ret)) { + case VM86_INTx: + { + int int_num, ah; + + int_num = VM86_ARG(ret); + if (int_num != 0x21) + goto unknown_int; + ah = (r->eax >> 8) & 0xff; + switch(ah) { + case 0x00: /* exit */ + exit(0); + case 0x02: /* write char */ + { + uint8_t c = r->edx; + write(1, &c, 1); + } + break; + case 0x09: /* write string */ + { + uint8_t c; + for(;;) { + c = *seg_to_linear(r->ds, r->edx); + if (c == '$') + break; + write(1, &c, 1); + } + r->eax = (r->eax & ~0xff) | '$'; + } + break; + default: + unknown_int: + fprintf(stderr, "unsupported int 0x%02x\n", int_num); + dump_regs(&ctx.regs); + // exit(1); + } + } + break; + case VM86_SIGNAL: + /* a signal came, we just ignore that */ + break; + case VM86_STI: + break; + default: + fprintf(stderr, "unhandled vm86 return code (0x%x)\n", ret); + dump_regs(&ctx.regs); + exit(1); + } + } +} |