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-rw-r--r--tests/runcom.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/tests/runcom.c b/tests/runcom.c
new file mode 100644
index 0000000000..2d41341c57
--- /dev/null
+++ b/tests/runcom.c
@@ -0,0 +1,188 @@
+/*
+ * Simple example of use of vm86: launch a basic .com DOS executable
+ */
+#include <stdlib.h>
+#include <stdio.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>
+
+//#define SIGTEST
+
+_syscall2(int, vm86, int, func, struct vm86plus_struct *, v86)
+
+#define COM_BASE_ADDR 0x10100
+
+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 = (IF_MASK | IOPL_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);
+ }
+ }
+}