From: bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Sun, 16 Mar 2003 18:05:05 +0000 (+0000)
Subject: added minimal segment support
X-Git-Tag: TizenStudio_2.0_p2.3~16185
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6dbad63eef5947c6c8750e44f408138779b6d0bb;p=sdk%2Femulator%2Fqemu.git

added minimal segment support


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@28 c046a42c-6fe2-441c-8c8c-71466251a162
---

diff --git a/TODO b/TODO
index caeb64d..5602097 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,5 @@
-- daa/das
-- optimize translated cache chaining (DLL PLT like system)
 - segment ops (minimal LDT/GDT support for wine)
+- optimize translated cache chaining (DLL PLT like system)
 - improved 16 bit support 
 - optimize inverse flags propagation (easy by generating intermediate
   micro operation array).
diff --git a/cpu-i386.h b/cpu-i386.h
index 40542f2..fc68a91 100644
--- a/cpu-i386.h
+++ b/cpu-i386.h
@@ -123,6 +123,20 @@ typedef long double CPU86_LDouble;
 typedef double CPU86_LDouble;
 #endif
 
+typedef struct SegmentCache {
+    uint8_t *base;
+    unsigned long limit;
+    uint8_t seg_32bit;
+} SegmentCache;
+
+typedef struct SegmentDescriptorTable {
+    uint8_t *base;
+    unsigned long limit;
+    /* this is the returned base when reading the register, just to
+    avoid that the emulated program modifies it */
+    unsigned long emu_base;
+} SegmentDescriptorTable;
+
 typedef struct CPUX86State {
     /* standard registers */
     uint32_t regs[8];
@@ -135,9 +149,6 @@ typedef struct CPUX86State {
     uint32_t cc_op;
     int32_t df; /* D flag : 1 if D = 0, -1 if D = 1 */
 
-    /* segments */
-    uint8_t *segs_base[6];
-
     /* FPU state */
     unsigned int fpstt; /* top of stack index */
     unsigned int fpus;
@@ -145,12 +156,19 @@ typedef struct CPUX86State {
     uint8_t fptags[8];   /* 0 = valid, 1 = empty */
     CPU86_LDouble fpregs[8];    
 
-    /* segments */
-    uint32_t segs[6];
-
     /* emulator internal variables */
     CPU86_LDouble ft0;
     
+    /* segments */
+    uint32_t segs[6]; /* selector values */
+    SegmentCache seg_cache[6]; /* info taken from LDT/GDT */
+    SegmentDescriptorTable gdt;
+    SegmentDescriptorTable ldt;
+    SegmentDescriptorTable idt;
+    
+    /* various CPU modes */
+    int vm86;
+
     /* exception handling */
     jmp_buf jmp_env;
     int exception_index;
@@ -241,9 +259,17 @@ CPUX86State *cpu_x86_init(void);
 int cpu_x86_exec(CPUX86State *s);
 void cpu_x86_close(CPUX86State *s);
 
+/* needed to load some predefinied segment registers */
+void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector);
+
 /* internal functions */
+
+#define GEN_FLAG_CODE32_SHIFT 0
+#define GEN_FLAG_ADDSEG_SHIFT 1
+#define GEN_FLAG_ST_SHIFT     2
 int cpu_x86_gen_code(uint8_t *gen_code_buf, int max_code_size, 
-                     int *gen_code_size_ptr, uint8_t *pc_start);
+                     int *gen_code_size_ptr, uint8_t *pc_start, 
+                     int flags);
 void cpu_x86_tblocks_init(void);
 
 #endif /* CPU_I386_H */
diff --git a/exec-i386.c b/exec-i386.c
index c067685..8144add 100644
--- a/exec-i386.c
+++ b/exec-i386.c
@@ -36,8 +36,10 @@
 #define CODE_GEN_MAX_BLOCKS    (CODE_GEN_BUFFER_SIZE / 64)
 #define CODE_GEN_HASH_BITS     15
 #define CODE_GEN_HASH_SIZE     (1 << CODE_GEN_HASH_BITS)
+
 typedef struct TranslationBlock {
     unsigned long pc;   /* simulated PC corresponding to this block */
+    unsigned int flags; /* flags defining in which context the code was generated */
     uint8_t *tc_ptr;    /* pointer to the translated code */
     struct TranslationBlock *hash_next; /* next matching block */
 } TranslationBlock;
@@ -137,7 +139,8 @@ static void tb_flush(void)
 
 /* find a translation block in the translation cache. If not found,
    allocate a new one */
-static inline TranslationBlock *tb_find_and_alloc(unsigned long pc)
+static inline TranslationBlock *tb_find_and_alloc(unsigned long pc, 
+                                                  unsigned int flags)
 {
     TranslationBlock **ptb, *tb;
     unsigned int h;
@@ -148,7 +151,7 @@ static inline TranslationBlock *tb_find_and_alloc(unsigned long pc)
         tb = *ptb;
         if (!tb)
             break;
-        if (tb->pc == pc)
+        if (tb->pc == pc && tb->flags == flags)
             return tb;
         ptb = &tb->hash_next;
     }
@@ -158,6 +161,7 @@ static inline TranslationBlock *tb_find_and_alloc(unsigned long pc)
     tb = &tbs[nb_tbs++];
     *ptb = tb;
     tb->pc = pc;
+    tb->flags = flags;
     tb->tc_ptr = NULL;
     tb->hash_next = NULL;
     return tb;
@@ -171,7 +175,8 @@ int cpu_x86_exec(CPUX86State *env1)
     void (*gen_func)(void);
     TranslationBlock *tb;
     uint8_t *tc_ptr;
-    
+    unsigned int flags;
+
     /* first we save global registers */
     saved_T0 = T0;
     saved_T1 = T1;
@@ -187,13 +192,20 @@ int cpu_x86_exec(CPUX86State *env1)
                 cpu_x86_dump_state();
             }
 #endif
-            tb = tb_find_and_alloc((unsigned long)env->pc);
+            /* we compute the CPU state. We assume it will not
+               change during the whole generated block. */
+            flags = env->seg_cache[R_CS].seg_32bit << GEN_FLAG_CODE32_SHIFT;
+            flags |= (((unsigned long)env->seg_cache[R_DS].base | 
+                       (unsigned long)env->seg_cache[R_ES].base |
+                       (unsigned long)env->seg_cache[R_SS].base) != 0) << 
+                GEN_FLAG_ADDSEG_SHIFT;
+            tb = tb_find_and_alloc((unsigned long)env->pc, flags);
             tc_ptr = tb->tc_ptr;
             if (!tb->tc_ptr) {
                 /* if no translated code available, then translate it now */
                 tc_ptr = code_gen_ptr;
                 cpu_x86_gen_code(code_gen_ptr, CODE_GEN_MAX_SIZE, 
-                                 &code_gen_size, (uint8_t *)env->pc);
+                                 &code_gen_size, (uint8_t *)env->pc, flags);
                 tb->tc_ptr = tc_ptr;
                 code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));
             }
@@ -211,3 +223,13 @@ int cpu_x86_exec(CPUX86State *env1)
     env = saved_env;
     return ret;
 }
+
+void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector)
+{
+    CPUX86State *saved_env;
+
+    saved_env = env;
+    env = s;
+    load_seg(seg_reg, selector);
+    env = saved_env;
+}
diff --git a/exec-i386.h b/exec-i386.h
index 62f681b..0e0cae2 100644
--- a/exec-i386.h
+++ b/exec-i386.h
@@ -27,6 +27,7 @@ typedef struct FILE FILE;
 extern FILE *logfile;
 extern int loglevel;
 extern int fprintf(FILE *, const char *, ...);
+extern int printf(const char *, ...);
 
 #ifdef __i386__
 register unsigned int T0 asm("ebx");
@@ -103,3 +104,5 @@ typedef struct CCTable {
 } CCTable;
 
 extern CCTable cc_table[];
+
+void load_seg(int seg_reg, int selector);
diff --git a/linux-user/main.c b/linux-user/main.c
index 6aefe3a..b59c85d 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -1,5 +1,5 @@
 /*
- *  emu main
+ *  gemu main
  * 
  *  Copyright (c) 2003 Fabrice Bellard
  *
@@ -80,10 +80,28 @@ int cpu_x86_inl(int addr)
     return 0;
 }
 
+/* default linux values for the selectors */
+#define __USER_CS	(0x23)
+#define __USER_DS	(0x2B)
 
-/* XXX: currently we use LDT entries */
-#define __USER_CS	(0x23|4)
-#define __USER_DS	(0x2B|4)
+void write_dt(void *ptr, unsigned long addr, unsigned long limit, 
+              int seg32_bit)
+{
+    unsigned int e1, e2, limit_in_pages;
+    limit_in_pages = 0;
+    if (limit > 0xffff) {
+        limit = limit >> 12;
+        limit_in_pages = 1;
+    }
+    e1 = (addr << 16) | (limit & 0xffff);
+    e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
+    e2 |= limit_in_pages << 23; /* byte granularity */
+    e2 |= seg32_bit << 22; /* 32 bit segment */
+    stl((uint8_t *)ptr, e1);
+    stl((uint8_t *)ptr + 4, e2);
+}
+
+uint64_t gdt_table[6];
 
 void usage(void)
 {
@@ -94,6 +112,8 @@ void usage(void)
     exit(1);
 }
 
+
+
 int main(int argc, char **argv)
 {
     const char *filename;
@@ -149,6 +169,7 @@ int main(int argc, char **argv)
 
     env = cpu_x86_init();
 
+    /* linux register setup */
     env->regs[R_EAX] = regs->eax;
     env->regs[R_EBX] = regs->ebx;
     env->regs[R_ECX] = regs->ecx;
@@ -157,23 +178,19 @@ int main(int argc, char **argv)
     env->regs[R_EDI] = regs->edi;
     env->regs[R_EBP] = regs->ebp;
     env->regs[R_ESP] = regs->esp;
-    env->segs[R_CS] = __USER_CS;
-    env->segs[R_DS] = __USER_DS;
-    env->segs[R_ES] = __USER_DS;
-    env->segs[R_SS] = __USER_DS;
-    env->segs[R_FS] = __USER_DS;
-    env->segs[R_GS] = __USER_DS;
     env->pc = regs->eip;
 
-#if 0
-    LDT[__USER_CS >> 3].w86Flags = DF_PRESENT | DF_PAGES | DF_32;
-    LDT[__USER_CS >> 3].dwSelLimit = 0xfffff;
-    LDT[__USER_CS >> 3].lpSelBase = NULL;
-
-    LDT[__USER_DS >> 3].w86Flags = DF_PRESENT | DF_PAGES | DF_32;
-    LDT[__USER_DS >> 3].dwSelLimit = 0xfffff;
-    LDT[__USER_DS >> 3].lpSelBase = NULL;
-#endif
+    /* linux segment setup */
+    env->gdt.base = (void *)gdt_table;
+    env->gdt.limit = sizeof(gdt_table) - 1;
+    write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1);
+    write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1);
+    cpu_x86_load_seg(env, R_CS, __USER_CS);
+    cpu_x86_load_seg(env, R_DS, __USER_DS);
+    cpu_x86_load_seg(env, R_ES, __USER_DS);
+    cpu_x86_load_seg(env, R_SS, __USER_DS);
+    cpu_x86_load_seg(env, R_FS, __USER_DS);
+    cpu_x86_load_seg(env, R_GS, __USER_DS);
 
     for(;;) {
         int err;
@@ -186,7 +203,8 @@ int main(int argc, char **argv)
             if (pc[0] == 0xcd && pc[1] == 0x80) {
                 /* syscall */
                 env->pc += 2;
-                env->regs[R_EAX] = do_syscall(env->regs[R_EAX], 
+                env->regs[R_EAX] = do_syscall(env, 
+                                              env->regs[R_EAX], 
                                               env->regs[R_EBX],
                                               env->regs[R_ECX],
                                               env->regs[R_EDX],
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 0b9de6b..4f09e6f 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -48,7 +48,7 @@ int elf_exec(const char * filename, char ** argv, char ** envp,
 
 void target_set_brk(char *new_brk);
 void syscall_init(void);
-long do_syscall(int num, long arg1, long arg2, long arg3, 
+long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3, 
                 long arg4, long arg5, long arg6);
 void gemu_log(const char *fmt, ...) __attribute__((format(printf,1,2)));
 
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ac40cf1..9ed8daa 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -69,6 +69,7 @@ struct dirent {
 #include "syscall_defs.h"
 
 #ifdef TARGET_I386
+#include "cpu-i386.h"
 #include "syscall-i386.h"
 #endif
 
@@ -607,6 +608,124 @@ StructEntry struct_termios_def = {
     .align = { __alignof__(struct target_termios), __alignof__(struct host_termios) },
 };
 
+#ifdef TARGET_I386
+
+/* NOTE: there is really one LDT for all the threads */
+uint8_t *ldt_table;
+
+static int read_ldt(void *ptr, unsigned long bytecount)
+{
+    int size;
+
+    if (!ldt_table)
+        return 0;
+    size = TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE;
+    if (size > bytecount)
+        size = bytecount;
+    memcpy(ptr, ldt_table, size);
+    return size;
+}
+
+/* XXX: add locking support */
+static int write_ldt(CPUX86State *env, 
+                     void *ptr, unsigned long bytecount, int oldmode)
+{
+    struct target_modify_ldt_ldt_s ldt_info;
+    int seg_32bit, contents, read_exec_only, limit_in_pages;
+    int seg_not_present, useable;
+    uint32_t *lp, entry_1, entry_2;
+
+    if (bytecount != sizeof(ldt_info))
+        return -EINVAL;
+    memcpy(&ldt_info, ptr, sizeof(ldt_info));
+    tswap32s(&ldt_info.entry_number);
+    tswapls((long *)&ldt_info.base_addr);
+    tswap32s(&ldt_info.limit);
+    tswap32s(&ldt_info.flags);
+    
+    if (ldt_info.entry_number >= TARGET_LDT_ENTRIES)
+        return -EINVAL;
+    seg_32bit = ldt_info.flags & 1;
+    contents = (ldt_info.flags >> 1) & 3;
+    read_exec_only = (ldt_info.flags >> 3) & 1;
+    limit_in_pages = (ldt_info.flags >> 4) & 1;
+    seg_not_present = (ldt_info.flags >> 5) & 1;
+    useable = (ldt_info.flags >> 6) & 1;
+
+    if (contents == 3) {
+        if (oldmode)
+            return -EINVAL;
+        if (seg_not_present == 0)
+            return -EINVAL;
+    }
+    /* allocate the LDT */
+    if (!ldt_table) {
+        ldt_table = malloc(TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE);
+        if (!ldt_table)
+            return -ENOMEM;
+        memset(ldt_table, 0, TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE);
+        env->ldt.base = ldt_table;
+        env->ldt.limit = 0xffff;
+    }
+
+    /* NOTE: same code as Linux kernel */
+    /* Allow LDTs to be cleared by the user. */
+    if (ldt_info.base_addr == 0 && ldt_info.limit == 0) {
+        if (oldmode ||
+            (contents == 0		&&
+             read_exec_only == 1	&&
+             seg_32bit == 0		&&
+             limit_in_pages == 0	&&
+             seg_not_present == 1	&&
+             useable == 0 )) {
+            entry_1 = 0;
+            entry_2 = 0;
+            goto install;
+        }
+    }
+    
+    entry_1 = ((ldt_info.base_addr & 0x0000ffff) << 16) |
+        (ldt_info.limit & 0x0ffff);
+    entry_2 = (ldt_info.base_addr & 0xff000000) |
+        ((ldt_info.base_addr & 0x00ff0000) >> 16) |
+        (ldt_info.limit & 0xf0000) |
+        ((read_exec_only ^ 1) << 9) |
+        (contents << 10) |
+        ((seg_not_present ^ 1) << 15) |
+        (seg_32bit << 22) |
+        (limit_in_pages << 23) |
+        0x7000;
+    if (!oldmode)
+        entry_2 |= (useable << 20);
+    
+    /* Install the new entry ...  */
+install:
+    lp = (uint32_t *)(ldt_table + (ldt_info.entry_number << 3));
+    lp[0] = tswap32(entry_1);
+    lp[1] = tswap32(entry_2);
+    return 0;
+}
+
+/* specific and weird i386 syscalls */
+int gemu_modify_ldt(CPUX86State *env, int func, void *ptr, unsigned long bytecount)
+{
+    int ret = -ENOSYS;
+    
+    switch (func) {
+    case 0:
+        ret = read_ldt(ptr, bytecount);
+        break;
+    case 1:
+        ret = write_ldt(env, ptr, bytecount, 1);
+        break;
+    case 0x11:
+        ret = write_ldt(env, ptr, bytecount, 0);
+        break;
+    }
+    return ret;
+}
+#endif
+
 void syscall_init(void)
 {
 #define STRUCT(name, list...) thunk_register_struct(STRUCT_ ## name, #name, struct_ ## name ## _def); 
@@ -616,7 +735,7 @@ void syscall_init(void)
 #undef STRUCT_SPECIAL
 }
                                  
-long do_syscall(int num, long arg1, long arg2, long arg3, 
+long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3, 
                 long arg4, long arg5, long arg6)
 {
     long ret;
@@ -1095,8 +1214,11 @@ long do_syscall(int num, long arg1, long arg2, long arg3,
         /* no need to transcode because we use the linux syscall */
         ret = get_errno(sys_uname((struct new_utsname *)arg1));
         break;
+#ifdef TARGET_I386
     case TARGET_NR_modify_ldt:
-        goto unimplemented;
+        ret = get_errno(gemu_modify_ldt(cpu_env, arg1, (void *)arg2, arg3));
+        break;
+#endif
     case TARGET_NR_adjtimex:
         goto unimplemented;
     case TARGET_NR_mprotect:
diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h
index 63852d3..5401144 100644
--- a/linux-user/syscall_types.h
+++ b/linux-user/syscall_types.h
@@ -61,4 +61,3 @@ STRUCT(cdrom_read_audio,
 
 STRUCT(hd_geometry,
        TYPE_CHAR, TYPE_CHAR, TYPE_SHORT, TYPE_ULONG)
-
diff --git a/op-i386.c b/op-i386.c
index 6d695ff..503fb88 100644
--- a/op-i386.c
+++ b/op-i386.c
@@ -858,6 +858,60 @@ void OPPROTO op_das(void)
     CC_SRC = eflags;
 }
 
+/* segment handling */
+
+void load_seg(int seg_reg, int selector)
+{
+    SegmentCache *sc;
+    SegmentDescriptorTable *dt;
+    int index;
+    uint32_t e1, e2;
+    uint8_t *ptr;
+
+    env->segs[seg_reg] = selector;
+    sc = &env->seg_cache[seg_reg];
+    if (env->vm86) {
+        sc->base = (void *)(selector << 4);
+        sc->limit = 0xffff;
+        sc->seg_32bit = 0;
+    } else {
+        if (selector & 0x4)
+            dt = &env->ldt;
+        else
+            dt = &env->gdt;
+        index = selector & ~7;
+        if ((index + 7) > dt->limit)
+            raise_exception(EXCP0D_GPF);
+        ptr = dt->base + index;
+        e1 = ldl(ptr);
+        e2 = ldl(ptr + 4);
+        sc->base = (void *)((e1 >> 16) | ((e2 & 0xff) << 16) | (e2 & 0xff000000));
+        sc->limit = (e1 & 0xffff) | (e2 & 0x000f0000);
+        if (e2 & (1 << 23))
+            sc->limit = (sc->limit << 12) | 0xfff;
+        sc->seg_32bit = (e2 >> 22) & 1;
+#if 0
+        fprintf(logfile, "load_seg: sel=0x%04x base=0x%08lx limit=0x%08lx seg_32bit=%d\n", 
+                selector, (unsigned long)sc->base, sc->limit, sc->seg_32bit);
+#endif
+    }
+}
+
+void OPPROTO op_movl_seg_T0(void)
+{
+    load_seg(PARAM1, T0 & 0xffff);
+}
+
+void OPPROTO op_movl_T0_seg(void)
+{
+    T0 = env->segs[PARAM1];
+}
+
+void OPPROTO op_addl_A0_seg(void)
+{
+    A0 += *(unsigned long *)((char *)env + PARAM1);
+}
+
 /* flags handling */
 
 /* slow jumps cases (compute x86 flags) */
diff --git a/syscall-i386.h b/syscall-i386.h
index 312edc6..a54064a 100644
--- a/syscall-i386.h
+++ b/syscall-i386.h
@@ -758,3 +758,14 @@ struct target_termios {
 #define TARGET_SOUND_MIXER_WRITE_ENHANCE  0xc0044d1f
 #define TARGET_SOUND_MIXER_WRITE_LOUD     0xc0044d1f
 #define TARGET_SOUND_MIXER_WRITE_RECSRC   0xc0044dff
+
+#define TARGET_LDT_ENTRIES      8192
+#define TARGET_LDT_ENTRY_SIZE	8
+
+struct target_modify_ldt_ldt_s {
+    unsigned int  entry_number;
+    target_ulong base_addr;
+    unsigned int limit;
+    unsigned int flags;
+};
+
diff --git a/tests/test-i386.c b/tests/test-i386.c
index b43ca59..95ec5d1 100644
--- a/tests/test-i386.c
+++ b/tests/test-i386.c
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <inttypes.h>
 #include <math.h>
 
 #define xglue(x, y) x ## y
@@ -612,6 +613,81 @@ void test_bcd(void)
     TEST_BCD(aad, 0x12340407, CC_A, (CC_C | CC_P | CC_Z | CC_S | CC_O | CC_A));
 }
 
+/**********************************************/
+/* segmentation tests */
+
+#include <asm/ldt.h>
+#include <linux/unistd.h>
+
+_syscall3(int, modify_ldt, int, func, void *, ptr, unsigned long, bytecount)
+
+uint8_t seg_data1[4096];
+uint8_t seg_data2[4096];
+
+#define MK_SEL(n) (((n) << 3) | 4)
+
+/* NOTE: we use Linux modify_ldt syscall */
+void test_segs(void)
+{
+    struct modify_ldt_ldt_s ldt;
+    long long ldt_table[3];
+    int i, res, res2;
+    char tmp;
+
+    ldt.entry_number = 1;
+    ldt.base_addr = (unsigned long)&seg_data1;
+    ldt.limit = (sizeof(seg_data1) + 0xfff) >> 12;
+    ldt.seg_32bit = 1;
+    ldt.contents = MODIFY_LDT_CONTENTS_DATA;
+    ldt.read_exec_only = 0;
+    ldt.limit_in_pages = 1;
+    ldt.seg_not_present = 0;
+    ldt.useable = 1;
+    modify_ldt(1, &ldt, sizeof(ldt)); /* write ldt entry */
+
+    ldt.entry_number = 2;
+    ldt.base_addr = (unsigned long)&seg_data2;
+    ldt.limit = (sizeof(seg_data2) + 0xfff) >> 12;
+    ldt.seg_32bit = 1;
+    ldt.contents = MODIFY_LDT_CONTENTS_DATA;
+    ldt.read_exec_only = 0;
+    ldt.limit_in_pages = 1;
+    ldt.seg_not_present = 0;
+    ldt.useable = 1;
+    modify_ldt(1, &ldt, sizeof(ldt)); /* write ldt entry */
+
+    modify_ldt(0, &ldt_table, sizeof(ldt_table)); /* read ldt entries */
+    for(i=0;i<3;i++)
+        printf("%d: %016Lx\n", i, ldt_table[i]);
+
+    /* do some tests with fs or gs */
+    asm volatile ("movl %0, %%fs" : : "r" (MK_SEL(1)));
+    asm volatile ("movl %0, %%gs" : : "r" (MK_SEL(2)));
+
+    seg_data1[1] = 0xaa;
+    seg_data2[1] = 0x55;
+
+    asm volatile ("fs movzbl 0x1, %0" : "=r" (res));
+    printf("FS[1] = %02x\n", res);
+
+    asm volatile ("gs movzbl 0x1, %0" : "=r" (res));
+    printf("GS[1] = %02x\n", res);
+
+    /* tests with ds/ss (implicit segment case) */
+    tmp = 0xa5;
+    asm volatile ("pushl %%ebp\n\t"
+                  "pushl %%ds\n\t"
+                  "movl %2, %%ds\n\t"
+                  "movl %3, %%ebp\n\t"
+                  "movzbl 0x1, %0\n\t"
+                  "movzbl (%%ebp), %1\n\t"
+                  "popl %%ds\n\t"
+                  "popl %%ebp\n\t"
+                  : "=r" (res), "=r" (res2)
+                  : "r" (MK_SEL(1)), "r" (&tmp));
+    printf("DS[1] = %02x\n", res);
+    printf("SS[tmp] = %02x\n", res2);
+}
 
 static void *call_end __init_call = NULL;
 
@@ -628,8 +704,9 @@ int main(int argc, char **argv)
     test_bsx();
     test_mul();
     test_jcc();
-    test_lea();
     test_floats();
     test_bcd();
+    test_lea();
+    test_segs();
     return 0;
 }
diff --git a/translate-i386.c b/translate-i386.c
index 0dbaa99..5146242 100644
--- a/translate-i386.c
+++ b/translate-i386.c
@@ -34,6 +34,10 @@
 #include "dis-asm.h"
 #endif
 
+#ifndef offsetof
+#define offsetof(type, field) ((size_t) &((type *)0)->field)
+#endif
+
 static uint8_t *gen_code_ptr;
 int __op_param1, __op_param2, __op_param3;
 
@@ -71,8 +75,13 @@ typedef struct DisasContext {
     int prefix;
     int aflag, dflag;
     uint8_t *pc; /* current pc */
-    int cc_op; /* current CC operation */
-    int f_st;
+    int is_jmp; /* 1 = means jump (stop translation), 2 means CPU
+                   static state change (stop translation) */
+    /* current block context */
+    int code32; /* 32 bit code segment */
+    int cc_op;  /* current CC operation */
+    int addseg; /* non zero if either DS/ES/SS have a non zero base */
+    int f_st;   /* currently unused */
 } DisasContext;
 
 /* i386 arith/logic operations */
@@ -763,12 +772,32 @@ static void gen_shifti(DisasContext *s1, int op, int ot, int d, int c)
 static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_ptr)
 {
     int havesib;
-    int havebase;
     int base, disp;
-    int index = 0;
-    int scale = 0;
-    int reg1, reg2, opreg;
-    int mod, rm, code;
+    int index;
+    int scale;
+    int opreg;
+    int mod, rm, code, override, must_add_seg;
+
+    /* XXX: add a generation time variable to tell if base == 0 in DS/ES/SS */
+    /* XXX: fix lea case */
+    override = -1;
+    must_add_seg = s->addseg;
+    if (s->prefix & (PREFIX_CS | PREFIX_SS | PREFIX_DS | 
+                     PREFIX_ES | PREFIX_FS | PREFIX_GS)) {
+        if (s->prefix & PREFIX_ES)
+            override = R_ES;
+        else if (s->prefix & PREFIX_CS)
+            override = R_CS;
+        else if (s->prefix & PREFIX_SS)
+            override = R_SS;
+        else if (s->prefix & PREFIX_DS)
+            override = R_DS;
+        else if (s->prefix & PREFIX_FS)
+            override = R_FS;
+        else
+            override = R_GS;
+        must_add_seg = 1;
+    }
 
     mod = (modrm >> 6) & 3;
     rm = modrm & 7;
@@ -776,8 +805,9 @@ static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_
     if (s->aflag) {
 
         havesib = 0;
-        havebase = 1;
         base = rm;
+        index = 0;
+        scale = 0;
         
         if (base == 4) {
             havesib = 1;
@@ -790,7 +820,7 @@ static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_
         switch (mod) {
         case 0:
             if (base == 5) {
-                havebase = 0;
+                base = -1;
                 disp = ldl(s->pc);
                 s->pc += 4;
             } else {
@@ -806,40 +836,25 @@ static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_
             s->pc += 4;
             break;
         }
-
-        reg1 = OR_ZERO;
-        reg2 = OR_ZERO;
-          
-        if (havebase || (havesib && (index != 4 || scale != 0))) {
-            if (havebase)
-                reg1 = OR_EAX + base;
-            if (havesib && index != 4) {
-                if (havebase)
-                    reg2 = index + OR_EAX;
-                else
-                    reg1 = index + OR_EAX;
-            }
-        }
-        /* XXX: disp only ? */
-        if (reg2 == OR_ZERO) {
-            /* op: disp + (reg1 << scale) */
-            if (reg1 == OR_ZERO) {
-                gen_op_movl_A0_im(disp);
-            } else if (scale == 0 && disp == 0) {
-                gen_op_movl_A0_reg[reg1]();
-            } else {
-                gen_op_movl_A0_im(disp);
-                gen_op_addl_A0_reg_sN[scale][reg1]();
-            }
+        
+        if (base >= 0) {
+            gen_op_movl_A0_reg[base]();
+            if (disp != 0)
+                gen_op_addl_A0_im(disp);
         } else {
-            /* op: disp + reg1 + (reg2 << scale) */
-            if (disp != 0) {
-                gen_op_movl_A0_im(disp);
-                gen_op_addl_A0_reg_sN[0][reg1]();
-            } else {
-                gen_op_movl_A0_reg[reg1]();
+            gen_op_movl_A0_im(disp);
+        }
+        if (havesib && (index != 4 || scale != 0)) {
+            gen_op_addl_A0_reg_sN[scale][index]();
+        }
+        if (must_add_seg) {
+            if (override < 0) {
+                if (base == R_EBP || base == R_ESP)
+                    override = R_SS;
+                else
+                    override = R_DS;
             }
-            gen_op_addl_A0_reg_sN[scale][reg2]();
+            gen_op_addl_A0_seg(offsetof(CPUX86State,seg_cache[override].base));
         }
     } else {
         switch (mod) {
@@ -848,6 +863,7 @@ static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_
                 disp = lduw(s->pc);
                 s->pc += 2;
                 gen_op_movl_A0_im(disp);
+                rm = 0; /* avoid SS override */
                 goto no_rm;
             } else {
                 disp = 0;
@@ -896,8 +912,18 @@ static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_
         if (disp != 0)
             gen_op_addl_A0_im(disp);
         gen_op_andl_A0_ffff();
-    no_rm: ;
+    no_rm:
+        if (must_add_seg) {
+            if (override < 0) {
+                if (rm == 2 || rm == 3 || rm == 6)
+                    override = R_SS;
+                else
+                    override = R_DS;
+            }
+            gen_op_addl_A0_seg(offsetof(CPUX86State,seg_cache[override].base));
+        }
     }
+
     opreg = OR_A0;
     disp = 0;
     *reg_ptr = opreg;
@@ -1082,10 +1108,19 @@ static void gen_setcc(DisasContext *s, int b)
     }
 }
 
+/* move T0 to seg_reg and compute if the CPU state may change */
+void gen_movl_seg_T0(DisasContext *s, int seg_reg)
+{
+    gen_op_movl_seg_T0(seg_reg);
+    if (!s->addseg && seg_reg < R_FS)
+        s->is_jmp = 2; /* abort translation because the register may
+                          have a non zero base */
+}
+
 /* return the next pc address. Return -1 if no insn found. *is_jmp_ptr
    is set to true if the instruction sets the PC (last instruction of
    a basic block) */
-long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
+long disas_insn(DisasContext *s, uint8_t *pc_start)
 {
     int b, prefixes, aflag, dflag;
     int shift, ot;
@@ -1093,8 +1128,8 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
 
     s->pc = pc_start;
     prefixes = 0;
-    aflag = 1;
-    dflag = 1;
+    aflag = s->code32;
+    dflag = s->code32;
     //    cur_pc = s->pc; /* for insn generation */
  next_byte:
     b = ldub(s->pc);
@@ -1416,11 +1451,11 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
             gen_op_movl_T1_im((long)s->pc);
             gen_op_pushl_T1();
             gen_op_jmp_T0();
-            *is_jmp_ptr = 1;
+            s->is_jmp = 1;
             break;
         case 4: /* jmp Ev */
             gen_op_jmp_T0();
-            *is_jmp_ptr = 1;
+            s->is_jmp = 1;
             break;
         case 6: /* push Ev */
             gen_op_pushl_T0();
@@ -1555,6 +1590,30 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         gen_op_popl_T0();
         gen_op_mov_reg_T0[OT_LONG][R_EBP]();
         break;
+    case 0x06: /* push es */
+    case 0x0e: /* push cs */
+    case 0x16: /* push ss */
+    case 0x1e: /* push ds */
+        gen_op_movl_T0_seg(b >> 3);
+        gen_op_pushl_T0();
+        break;
+    case 0x1a0: /* push fs */
+    case 0x1a8: /* push gs */
+        gen_op_movl_T0_seg(((b >> 3) & 7) + R_FS);
+        gen_op_pushl_T0();
+        break;
+    case 0x07: /* pop es */
+    case 0x17: /* pop ss */
+    case 0x1f: /* pop ds */
+        gen_op_popl_T0();
+        gen_movl_seg_T0(s, b >> 3);
+        break;
+    case 0x1a1: /* pop fs */
+    case 0x1a9: /* pop gs */
+        gen_op_popl_T0();
+        gen_movl_seg_T0(s, ((b >> 3) & 7) + R_FS);
+        break;
+
         /**************************/
         /* mov */
     case 0x88:
@@ -1598,6 +1657,24 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         gen_ldst_modrm(s, modrm, ot, OR_TMP0, 0);
         gen_op_mov_reg_T0[ot][reg]();
         break;
+    case 0x8e: /* mov seg, Gv */
+        ot = dflag ? OT_LONG : OT_WORD;
+        modrm = ldub(s->pc++);
+        reg = (modrm >> 3) & 7;
+        gen_ldst_modrm(s, modrm, ot, OR_TMP0, 0);
+        if (reg >= 6)
+            goto illegal_op;
+        gen_movl_seg_T0(s, reg);
+        break;
+    case 0x8c: /* mov Gv, seg */
+        ot = dflag ? OT_LONG : OT_WORD;
+        modrm = ldub(s->pc++);
+        reg = (modrm >> 3) & 7;
+        if (reg >= 6)
+            goto illegal_op;
+        gen_op_movl_T0_seg(reg);
+        gen_ldst_modrm(s, modrm, ot, OR_TMP0, 1);
+        break;
 
     case 0x1b6: /* movzbS Gv, Eb */
     case 0x1b7: /* movzwS Gv, Eb */
@@ -1648,8 +1725,13 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         ot = dflag ? OT_LONG : OT_WORD;
         modrm = ldub(s->pc++);
         reg = (modrm >> 3) & 7;
-
+        /* we must ensure that no segment is added */
+        s->prefix &= ~(PREFIX_CS | PREFIX_SS | PREFIX_DS | 
+                       PREFIX_ES | PREFIX_FS | PREFIX_GS);
+        val = s->addseg;
+        s->addseg = 0;
         gen_lea_modrm(s, modrm, &reg_addr, &offset_addr);
+        s->addseg = val;
         gen_op_mov_reg_A0[ot - OT_WORD][reg]();
         break;
         
@@ -1711,6 +1793,35 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         gen_op_st_T0_A0[ot]();
         gen_op_mov_reg_T1[ot][reg]();
         break;
+    case 0xc4: /* les Gv */
+        op = R_ES;
+        goto do_lxx;
+    case 0xc5: /* lds Gv */
+        op = R_DS;
+        goto do_lxx;
+    case 0x1b2: /* lss Gv */
+        op = R_SS;
+        goto do_lxx;
+    case 0x1b4: /* lfs Gv */
+        op = R_FS;
+        goto do_lxx;
+    case 0x1b5: /* lgs Gv */
+        op = R_GS;
+    do_lxx:
+        ot = dflag ? OT_LONG : OT_WORD;
+        modrm = ldub(s->pc++);
+        reg = (modrm >> 3) & 7;
+        mod = (modrm >> 6) & 3;
+        if (mod == 3)
+            goto illegal_op;
+        gen_op_ld_T1_A0[ot]();
+        op_addl_A0_im(1 << (ot - OT_WORD + 1));
+        /* load the segment first to handle exceptions properly */
+        gen_op_lduw_T0_A0();
+        gen_movl_seg_T0(s, op);
+        /* then put the data */
+        gen_op_mov_reg_T1[ot][reg]();
+        break;
         
         /************************/
         /* shifts */
@@ -2327,12 +2438,12 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         gen_op_popl_T0();
         gen_op_addl_ESP_im(val);
         gen_op_jmp_T0();
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0xc3: /* ret */
         gen_op_popl_T0();
         gen_op_jmp_T0();
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0xe8: /* call */
         val = insn_get(s, OT_LONG);
@@ -2340,19 +2451,19 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         gen_op_movl_T1_im((long)s->pc);
         gen_op_pushl_T1();
         gen_op_jmp_im(val);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0xe9: /* jmp */
         val = insn_get(s, OT_LONG);
         val += (long)s->pc;
         gen_op_jmp_im(val);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0xeb: /* jmp Jb */
         val = (int8_t)insn_get(s, OT_BYTE);
         val += (long)s->pc;
         gen_op_jmp_im(val);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0x70 ... 0x7f: /* jcc Jb */
         val = (int8_t)insn_get(s, OT_BYTE);
@@ -2367,7 +2478,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         val += (long)s->pc; /* XXX: fix 16 bit wrap */
     do_jcc:
         gen_jcc(s, b, val);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
 
     case 0x190 ... 0x19f:
@@ -2548,19 +2659,19 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         break;
     case 0xcc: /* int3 */
         gen_op_int3((long)pc_start);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0xcd: /* int N */
         val = ldub(s->pc++);
         /* XXX: currently we ignore the interrupt number */
         gen_op_int_im((long)pc_start);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0xce: /* into */
         if (s->cc_op != CC_OP_DYNAMIC)
             gen_op_set_cc_op(s->cc_op);
         gen_op_into((long)pc_start, (long)s->pc);
-        *is_jmp_ptr = 1;
+        s->is_jmp = 1;
         break;
     case 0x1c8 ... 0x1cf: /* bswap reg */
         reg = b & 7;
@@ -2586,38 +2697,43 @@ long disas_insn(DisasContext *s, uint8_t *pc_start, int *is_jmp_ptr)
         return -1;
     }
     return (long)s->pc;
+ illegal_op:
+    error("illegal opcode pc=0x%08Lx", (long)pc_start);
+    return -1;
 }
 
 /* return the next pc */
 int cpu_x86_gen_code(uint8_t *gen_code_buf, int max_code_size, 
-                     int *gen_code_size_ptr, uint8_t *pc_start)
+                     int *gen_code_size_ptr, uint8_t *pc_start, 
+                     int flags)
 {
     DisasContext dc1, *dc = &dc1;
     uint8_t *gen_code_end, *pc_ptr;
-    int is_jmp;
     long ret;
 #ifdef DEBUG_DISAS
     struct disassemble_info disasm_info;
 #endif
-
+    dc->code32 = (flags >> GEN_FLAG_CODE32_SHIFT) & 1;
+    dc->addseg = (flags >> GEN_FLAG_ADDSEG_SHIFT) & 1;
+    dc->f_st = (flags >> GEN_FLAG_ST_SHIFT) & 7;
     dc->cc_op = CC_OP_DYNAMIC;
     gen_code_ptr = gen_code_buf;
     gen_code_end = gen_code_buf + max_code_size - 4096;
     gen_start();
 
-    is_jmp = 0;
+    dc->is_jmp = 0;
     pc_ptr = pc_start;
     do {
-        ret = disas_insn(dc, pc_ptr, &is_jmp);
+        ret = disas_insn(dc, pc_ptr);
         if (ret == -1) 
             error("unknown instruction at PC=0x%x B=%02x %02x", 
                   pc_ptr, pc_ptr[0], pc_ptr[1]);
         pc_ptr = (void *)ret;
-    } while (!is_jmp && gen_code_ptr < gen_code_end);
+    } while (!dc->is_jmp && gen_code_ptr < gen_code_end);
     /* we must store the eflags state if it is not already done */
     if (dc->cc_op != CC_OP_DYNAMIC)
         gen_op_set_cc_op(dc->cc_op);
-    if (!is_jmp) {
+    if (dc->is_jmp != 1) {
         /* we add an additionnal jmp to update the simulated PC */
         gen_op_jmp_im(ret);
     }