added user mode libqemu usage example

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@739 c046a42c-6fe2-441c-8c8c-71466251a162

tests/Makefile

@@ -62,6 +62,11 @@ speed: sha1 sha1-i386
 runcom: runcom.c
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<
 
+# NOTE: -fomit-frame-pointer is currently needed : this is a bug in libqemu
+qruncom: qruncom.c ../i386-user/libqemu.a
+	$(CC) $(CFLAGS) -fomit-frame-pointer $(LDFLAGS) -I../target-i386 -I.. -I../i386-user \
+              -o $@ $< -L../i386-user -lqemu -lm
+
 # arm test
 hello-arm: hello-arm.o
 	arm-linux-ld -o $@ $<

tests/qruncom.c

+/*
+ * Example of use of user mode libqemu: 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 "cpu.h"
+
+//#define SIGTEST
+
+CPUState *cpu_single_env = NULL;
+
+void cpu_outb(CPUState *env, int addr, int val)
+{
+    fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
+}
+
+void cpu_outw(CPUState *env, int addr, int val)
+{
+    fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
+}
+
+void cpu_outl(CPUState *env, int addr, int val)
+{
+    fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
+}
+
+int cpu_inb(CPUState *env, int addr)
+{
+    fprintf(stderr, "inb: port=0x%04x\n", addr);
+    return 0;
+}
+
+int cpu_inw(CPUState *env, int addr)
+{
+    fprintf(stderr, "inw: port=0x%04x\n", addr);
+    return 0;
+}
+
+int cpu_inl(CPUState *env, int addr)
+{
+    fprintf(stderr, "inl: port=0x%04x\n", addr);
+    return 0;
+}
+
+int cpu_get_pic_interrupt(CPUState *env)
+{
+    return -1;
+}
+
+static void set_gate(void *ptr, unsigned int type, unsigned int dpl, 
+                     unsigned long addr, unsigned int sel)
+{
+    unsigned int e1, e2;
+    e1 = (addr & 0xffff) | (sel << 16);
+    e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
+    stl((uint8_t *)ptr, e1);
+    stl((uint8_t *)ptr + 4, e2);
+}
+
+uint64_t idt_table[256];
+
+/* only dpl matters as we do only user space emulation */
+static void set_idt(int n, unsigned int dpl)
+{
+    set_gate(idt_table + n, 0, dpl, 0, 0);
+}
+
+void qemu_free(void *ptr)
+{
+    free(ptr);
+}
+
+void *qemu_malloc(size_t size)
+{
+    return malloc(size);
+}
+
+void qemu_printf(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    vprintf(fmt, ap);
+    va_end(ap);
+}
+
+/* XXX: this is a bug in helper2.c */
+int errno;
+
+/**********************************************/
+
+#define COM_BASE_ADDR    0x10100
+
+void usage(void)
+{
+    printf("qruncom version 0.1 (c) 2003 Fabrice Bellard\n"
+           "usage: qruncom file.com\n"
+           "user mode libqemu demo: run simple .com DOS executables\n");
+    exit(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(CPUState *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].selector, env->regs[R_ESP]) = val;
+}
+
+static void host_segv_handler(int host_signum, siginfo_t *info, 
+                              void *puc)
+{
+    if (cpu_signal_handler(host_signum, info, puc)) {
+        return;
+    }
+    abort();
+}
+
+int main(int argc, char **argv)
+{
+    uint8_t *vm86_mem;
+    const char *filename;
+    int fd, ret, seg;
+    CPUState *env;
+
+    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);
+    }
+
+    /* 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);
+
+    /* install exception handler for CPU emulator */
+    {
+        struct sigaction act;
+        
+        sigfillset(&act.sa_mask);
+        act.sa_flags = SA_SIGINFO;
+        //        act.sa_flags |= SA_ONSTACK;
+
+        act.sa_sigaction = host_segv_handler;
+        sigaction(SIGSEGV, &act, NULL);
+        sigaction(SIGBUS, &act, NULL);
+#if defined (TARGET_I386) && defined(USE_CODE_COPY)
+        sigaction(SIGFPE, &act, NULL);
+#endif
+    }
+
+    //    cpu_set_log(CPU_LOG_TB_IN_ASM | CPU_LOG_TB_OUT_ASM | CPU_LOG_EXEC);
+
+    env = cpu_init();
+
+    /* disable code copy to simplify debugging */
+    code_copy_enabled = 0;
+
+    /* set user mode state (XXX: should be done automatically by
+       cpu_init ?) */
+    env->user_mode_only = 1;
+
+    cpu_x86_set_cpl(env, 3);
+
+    env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
+    /* NOTE: hflags duplicates some of the virtual CPU state */
+    env->hflags |= HF_PE_MASK | VM_MASK;
+
+    /* flags setup : we activate the IRQs by default as in user
+       mode. We also activate the VM86 flag to run DOS code */
+    env->eflags |= IF_MASK | VM_MASK;
+    
+    /* init basic registers */
+    env->eip = 0x100;
+    env->regs[R_ESP] = 0xfffe;
+    seg = (COM_BASE_ADDR - 0x100) >> 4;
+
+    cpu_x86_load_seg_cache(env, R_CS, seg, 
+                           (uint8_t *)(seg << 4), 0xffff, 0);
+    cpu_x86_load_seg_cache(env, R_SS, seg, 
+                           (uint8_t *)(seg << 4), 0xffff, 0);
+    cpu_x86_load_seg_cache(env, R_DS, seg, 
+                           (uint8_t *)(seg << 4), 0xffff, 0);
+    cpu_x86_load_seg_cache(env, R_ES, seg, 
+                           (uint8_t *)(seg << 4), 0xffff, 0);
+    cpu_x86_load_seg_cache(env, R_FS, seg, 
+                           (uint8_t *)(seg << 4), 0xffff, 0);
+    cpu_x86_load_seg_cache(env, R_GS, seg, 
+                           (uint8_t *)(seg << 4), 0xffff, 0);
+
+    /* exception support */
+    env->idt.base = (void *)idt_table;
+    env->idt.limit = sizeof(idt_table) - 1;
+    set_idt(0, 0);
+    set_idt(1, 0);
+    set_idt(2, 0);
+    set_idt(3, 3);
+    set_idt(4, 3);
+    set_idt(5, 3);
+    set_idt(6, 0);
+    set_idt(7, 0);
+    set_idt(8, 0);
+    set_idt(9, 0);
+    set_idt(10, 0);
+    set_idt(11, 0);
+    set_idt(12, 0);
+    set_idt(13, 0);
+    set_idt(14, 0);
+    set_idt(15, 0);
+    set_idt(16, 0);
+    set_idt(17, 0);
+    set_idt(18, 0);
+    set_idt(19, 0);
+        
+    /* put return code */
+    *seg_to_linear(env->segs[R_CS].selector, 0) = 0xb4; /* mov ah, $0 */
+    *seg_to_linear(env->segs[R_CS].selector, 1) = 0x00;
+    *seg_to_linear(env->segs[R_CS].selector, 2) = 0xcd; /* int $0x21 */
+    *seg_to_linear(env->segs[R_CS].selector, 3) = 0x21;
+    pushw(env, 0x0000);
+
+    /* the value of these registers seem to be assumed by pi_10.com */
+    env->regs[R_ESI] = 0x100;
+    env->regs[R_ECX] = 0xff;
+    env->regs[R_EBP] = 0x0900;
+    env->regs[R_EDI] = 0xfffe;
+
+    /* inform the emulator of the mmaped memory */
+    page_set_flags(0x00000000, 0x110000, 
+                   PAGE_WRITE | PAGE_READ | PAGE_EXEC | PAGE_VALID);
+
+    for(;;) {
+        ret = cpu_x86_exec(env);
+        switch(ret) {
+        case EXCP0D_GPF:
+            {
+                int int_num, ah;
+                int_num = *(env->segs[R_CS].base + env->eip + 1);
+                if (int_num != 0x21)
+                    goto unknown_int;
+                ah = (env->regs[R_EAX] >> 8) & 0xff;
+                switch(ah) {
+                case 0x00: /* exit */
+                    exit(0);
+                case 0x02: /* write char */
+                    {
+                        uint8_t c = env->regs[R_EDX];
+                        write(1, &c, 1);
+                    }
+                    break;
+                case 0x09: /* write string */
+                    {
+                        uint8_t c;
+                        for(;;) {
+                            c = *seg_to_linear(env->segs[R_DS].selector, env->regs[R_EAX]);
+                            if (c == '$')
+                                break;
+                            write(1, &c, 1);
+                        }
+                        env->regs[R_EAX] = (env->regs[R_EAX] & ~0xff) | '$';
+                    }
+                    break;
+                default:
+                unknown_int:
+                    fprintf(stderr, "unsupported int 0x%02x\n", int_num);
+                    cpu_dump_state(env, stderr, 0);
+                    //                    exit(1);
+                }
+                env->eip += 2;
+            }
+            break;
+        default:
+            fprintf(stderr, "unhandled cpu_exec return code (0x%x)\n", ret);
+            cpu_dump_state(env, stderr, 0);
+            exit(1);
+        }
+    }
+}