void
load_overlay(int fd, int start_segment, int reloc_segment)
{
struct exehdr hdr;
int text_size;
int exe_file;
/* read exe header */
if (read (fd, &hdr, sizeof hdr) != sizeof hdr)
fatal ("can't read header\n");
/* proper header ? */
if (hdr.magic == 0x5a4d) {
exe_file = 1;
text_size = (hdr.size - 1) * 512 + hdr.bytes_on_last_page
- hdr.hdr_size * 16;
} else {
exe_file = 0;
}
if (!exe_file)
load_com(fd, start_segment);
else
load_exe(fd, start_segment, reloc_segment, &hdr, text_size);
}
int main(int argc, char **argv)
{
uc_engine *uc;
uc_hook trace;
uc_err err;
uint8_t memory[MEM_SIZE];
if (argc == 1) {
usage(argv[0]);
return -1;
}
const char *fname = argv[1];
err = uc_open (UC_ARCH_X86, UC_MODE_16, &uc);
if (err) {
fprintf(stderr, "Cannot initialize unicorn\n");
return 1;
}
// map 64KB in
if (uc_mem_map (uc, 0, MEM_SIZE, UC_PROT_ALL)) {
fprintf(stderr, "Failed to write emulation code to memory, quit!\n");
uc_close(uc);
return 0;
}
// initialize internal settings
int21_init();
//load executable
size_t fsize = load_com(uc, memory, fname);
// setup PSP
setup_psp(0, memory, argc, argv);
// write machine code to be emulated in, including the prefix PSP
uc_mem_write(uc, 0, memory, DOS_ADDR + fsize);
// handle interrupt ourself
uc_hook_add(uc, &trace, UC_HOOK_INTR, hook_intr, NULL);
err = uc_emu_start(uc, DOS_ADDR, DOS_ADDR + 0x10000, 0, 0);
if (err) {
fprintf(stderr, "Failed on uc_emu_start() with error returned %u: %s\n",
err, uc_strerror(err));
}
uc_close(uc);
return 0;
}
void
load_command(regcontext_t *REGS, int run, int fd, char *cmd_name,
u_short *param, char **argv, char **envs)
{
struct exehdr hdr;
int min_memory, max_memory;
int biggest;
int envseg;
char *psp;
int text_size = 0;
int i;
int start_segment;
int exe_file;
char *p;
int used, n;
char *fcb;
int newpsp;
u_short init_cs, init_ip, init_ss, init_sp, init_ds, init_es;
if (envs)
envseg = make_environment(cmd_name, envs);
else
envseg = env_s[curpsp];
/* read exe header */
if (read (fd, &hdr, sizeof hdr) != sizeof hdr)
fatal ("can't read header\n");
/* proper header ? */
if (hdr.magic == 0x5a4d) {
exe_file = 1;
text_size = (hdr.size - 1) * 512 + hdr.bytes_on_last_page
- hdr.hdr_size * 16;
min_memory = hdr.min_memory + (text_size + 15)/16;
max_memory = hdr.max_memory + (text_size + 15)/16;
} else {
exe_file = 0;
min_memory = 64 * (1024/16);
max_memory = 0xffff;
}
/* alloc mem block */
pspseg = mem_alloc(max_memory, 1, &biggest);
if (pspseg == 0) {
if (biggest < min_memory ||
(pspseg = mem_alloc(biggest, 1, NULL)) == 0)
fatal("not enough memory: needed %d have %d\n",
min_memory, biggest);
max_memory = biggest;
}
mem_change_owner(pspseg, pspseg);
mem_change_owner(envseg, pspseg);
/* create psp */
newpsp = curpsp + 1;
psp_s[newpsp] = pspseg;
env_s[newpsp] = envseg;
psp = (char *)MAKEPTR(pspseg, 0);
memset(psp, 0, 256);
psp[0] = 0xcd;
psp[1] = 0x20;
*(u_short *)&psp[2] = pspseg + max_memory;
/*
* this is supposed to be a long call to dos ... try to fake it
*/
psp[5] = 0xcd;
psp[6] = 0x99;
psp[7] = 0xc3;
*(u_short *)&psp[0x16] = psp_s[curpsp];
psp[0x18] = 1;
psp[0x19] = 1;
psp[0x1a] = 1;
psp[0x1b] = 0;
psp[0x1c] = 2;
memset(psp + 0x1d, 0xff, 15);
*(u_short *)&psp[0x2c] = envseg;
*(u_short *)&psp[0x32] = 20;
*(u_long *)&psp[0x34] = MAKEVEC(pspseg, 0x18);
*(u_long *)&psp[0x38] = 0xffffffff;
psp[0x50] = 0xcd;
psp[0x51] = 0x98;
psp[0x52] = 0xc3;
p = psp + 0x81;
*p = 0;
used = 0;
for (i = 0; argv[i]; i++) {
n = strlen(argv[i]);
if (used + 1 + n > 0x7d)
break;
*p++ = ' ';
memcpy(p, argv[i], n);
p += n;
used += n;
}
psp[0x80] = strlen(psp + 0x81);
psp[0x81 + psp[0x80]] = 0x0d;
psp[0x82 + psp[0x80]] = 0;
p = psp + 0x81;
parse_filename(0x00, p, psp + 0x5c, &n);
p += n;
parse_filename(0x00, p, psp + 0x6c, &n);
if (param[4]) {
fcb = (char *)MAKEPTR(param[4], param[3]);
memcpy(psp + 0x5c, fcb, 16);
}
if (param[6]) {
fcb = (char *)MAKEPTR(param[6], param[5]);
memcpy(psp + 0x6c, fcb, 16);
}
#if 0
printf("005c:");
for (n = 0; n < 16; n++)
printf(" %02x", psp[0x5c + n]);
printf("\n");
printf("006c:");
for (n = 0; n < 16; n++)
printf(" %02x", psp[0x6c + n]);
printf("\n");
#endif
disk_transfer_addr = MAKEVEC(pspseg, 0x80);
start_segment = pspseg + 0x10;
if (!exe_file) {
load_com(fd, start_segment);
init_cs = pspseg;
init_ip = 0x100;
init_ss = init_cs;
init_sp = 0xfffe;
init_ds = init_cs;
init_es = init_cs;
} else {
load_exe(fd, start_segment, start_segment, &hdr, text_size);
init_cs = hdr.init_cs + start_segment;
init_ip = hdr.init_ip;
init_ss = hdr.init_ss + start_segment;
init_sp = hdr.init_sp;
init_ds = pspseg;
init_es = init_ds;
}
debug(D_EXEC, "cs:ip = %04x:%04x, ss:sp = %04x:%04x, "
"ds = %04x, es = %04x\n",
init_cs, init_ip, init_ss, init_sp, init_ds, init_es);
if (run) {
frames[newpsp] = *REGS;
curpsp = newpsp;
R_EFLAGS = 0x20202;
R_CS = init_cs;
R_IP = init_ip;
R_SS = init_ss;
R_SP = init_sp;
R_DS = init_ds;
R_ES = init_es;
R_AX = R_BX = R_CX = R_DX = R_SI = R_DI = R_BP = 0;
} else {
param[7] = init_sp;
param[8] = init_ss;
param[9] = init_ip;
param[10] = init_cs;
}
}
