2 * Example of use of user mode libqemu: launch a basic .com DOS
18 void cpu_outb(CPUState *env, int addr, int val)
20 fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
23 void cpu_outw(CPUState *env, int addr, int val)
25 fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
28 void cpu_outl(CPUState *env, int addr, int val)
30 fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
33 int cpu_inb(CPUState *env, int addr)
35 fprintf(stderr, "inb: port=0x%04x\n", addr);
39 int cpu_inw(CPUState *env, int addr)
41 fprintf(stderr, "inw: port=0x%04x\n", addr);
45 int cpu_inl(CPUState *env, int addr)
47 fprintf(stderr, "inl: port=0x%04x\n", addr);
51 int cpu_get_pic_interrupt(CPUState *env)
56 uint64_t cpu_get_tsc(CPUState *env)
61 static void set_gate(void *ptr, unsigned int type, unsigned int dpl,
62 unsigned long addr, unsigned int sel)
65 e1 = (addr & 0xffff) | (sel << 16);
66 e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
67 stl((uint8_t *)ptr, e1);
68 stl((uint8_t *)ptr + 4, e2);
71 uint64_t idt_table[256];
73 /* only dpl matters as we do only user space emulation */
74 static void set_idt(int n, unsigned int dpl)
76 set_gate(idt_table + n, 0, dpl, 0, 0);
79 void qemu_free(void *ptr)
84 void *qemu_malloc(size_t size)
89 void qemu_printf(const char *fmt, ...)
97 /* XXX: this is a bug in helper2.c */
100 /**********************************************/
102 #define COM_BASE_ADDR 0x10100
106 printf("qruncom version 0.1 (c) 2003 Fabrice Bellard\n"
107 "usage: qruncom file.com\n"
108 "user mode libqemu demo: run simple .com DOS executables\n");
112 static inline uint8_t *seg_to_linear(unsigned int seg, unsigned int reg)
114 return (uint8_t *)((seg << 4) + (reg & 0xffff));
117 static inline void pushw(CPUState *env, int val)
119 env->regs[R_ESP] = (env->regs[R_ESP] & ~0xffff) | ((env->regs[R_ESP] - 2) & 0xffff);
120 *(uint16_t *)seg_to_linear(env->segs[R_SS].selector, env->regs[R_ESP]) = val;
123 static void host_segv_handler(int host_signum, siginfo_t *info,
126 if (cpu_signal_handler(host_signum, info, puc)) {
132 int main(int argc, char **argv)
135 const char *filename;
143 vm86_mem = mmap((void *)0x00000000, 0x110000,
144 PROT_WRITE | PROT_READ | PROT_EXEC,
145 MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0);
146 if (vm86_mem == MAP_FAILED) {
151 /* load the MSDOS .com executable */
152 fd = open(filename, O_RDONLY);
157 ret = read(fd, vm86_mem + COM_BASE_ADDR, 65536 - 256);
164 /* install exception handler for CPU emulator */
166 struct sigaction act;
168 sigfillset(&act.sa_mask);
169 act.sa_flags = SA_SIGINFO;
170 // act.sa_flags |= SA_ONSTACK;
172 act.sa_sigaction = host_segv_handler;
173 sigaction(SIGSEGV, &act, NULL);
174 sigaction(SIGBUS, &act, NULL);
175 #if defined (TARGET_I386) && defined(USE_CODE_COPY)
176 sigaction(SIGFPE, &act, NULL);
180 // cpu_set_log(CPU_LOG_TB_IN_ASM | CPU_LOG_TB_OUT_ASM | CPU_LOG_EXEC);
184 /* disable code copy to simplify debugging */
185 code_copy_enabled = 0;
187 /* set user mode state (XXX: should be done automatically by
189 env->user_mode_only = 1;
191 cpu_x86_set_cpl(env, 3);
193 env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
194 /* NOTE: hflags duplicates some of the virtual CPU state */
195 env->hflags |= HF_PE_MASK | VM_MASK;
197 /* flags setup : we activate the IRQs by default as in user
198 mode. We also activate the VM86 flag to run DOS code */
199 env->eflags |= IF_MASK | VM_MASK;
201 /* init basic registers */
203 env->regs[R_ESP] = 0xfffe;
204 seg = (COM_BASE_ADDR - 0x100) >> 4;
206 cpu_x86_load_seg_cache(env, R_CS, seg,
207 (uint8_t *)(seg << 4), 0xffff, 0);
208 cpu_x86_load_seg_cache(env, R_SS, seg,
209 (uint8_t *)(seg << 4), 0xffff, 0);
210 cpu_x86_load_seg_cache(env, R_DS, seg,
211 (uint8_t *)(seg << 4), 0xffff, 0);
212 cpu_x86_load_seg_cache(env, R_ES, seg,
213 (uint8_t *)(seg << 4), 0xffff, 0);
214 cpu_x86_load_seg_cache(env, R_FS, seg,
215 (uint8_t *)(seg << 4), 0xffff, 0);
216 cpu_x86_load_seg_cache(env, R_GS, seg,
217 (uint8_t *)(seg << 4), 0xffff, 0);
219 /* exception support */
220 env->idt.base = (void *)idt_table;
221 env->idt.limit = sizeof(idt_table) - 1;
243 /* put return code */
244 *seg_to_linear(env->segs[R_CS].selector, 0) = 0xb4; /* mov ah, $0 */
245 *seg_to_linear(env->segs[R_CS].selector, 1) = 0x00;
246 *seg_to_linear(env->segs[R_CS].selector, 2) = 0xcd; /* int $0x21 */
247 *seg_to_linear(env->segs[R_CS].selector, 3) = 0x21;
250 /* the value of these registers seem to be assumed by pi_10.com */
251 env->regs[R_ESI] = 0x100;
252 env->regs[R_ECX] = 0xff;
253 env->regs[R_EBP] = 0x0900;
254 env->regs[R_EDI] = 0xfffe;
256 /* inform the emulator of the mmaped memory */
257 page_set_flags(0x00000000, 0x110000,
258 PAGE_WRITE | PAGE_READ | PAGE_EXEC | PAGE_VALID);
261 ret = cpu_x86_exec(env);
266 int_num = *(env->segs[R_CS].base + env->eip + 1);
269 ah = (env->regs[R_EAX] >> 8) & 0xff;
271 case 0x00: /* exit */
273 case 0x02: /* write char */
275 uint8_t c = env->regs[R_EDX];
279 case 0x09: /* write string */
283 c = *seg_to_linear(env->segs[R_DS].selector, env->regs[R_EAX]);
288 env->regs[R_EAX] = (env->regs[R_EAX] & ~0xff) | '$';
293 fprintf(stderr, "unsupported int 0x%02x\n", int_num);
294 cpu_dump_state(env, stderr, 0);
301 fprintf(stderr, "unhandled cpu_exec return code (0x%x)\n", ret);
302 cpu_dump_state(env, stderr, 0);