Commit 8f186479 authored by bellard's avatar bellard
Browse files

real mode support (now boots from BOCHS BIOS and LGPL'ed VGA BIOS)


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@333 c046a42c-6fe2-441c-8c8c-71466251a162
parent 4c3a88a2
......@@ -788,6 +788,37 @@ static inline void load_seg_vm(int seg, int selector)
sc->limit = 0xffff;
}
/* real mode iret */
void helper_iret_real(int shift)
{
uint32_t sp, new_cs, new_eip, new_eflags, new_esp;
uint8_t *ssp;
int eflags_mask;
sp = env->regs[R_ESP] & 0xffff;
ssp = env->segs[R_SS].base + sp;
if (shift == 1) {
/* 32 bits */
new_eflags = ldl(ssp + 8);
new_cs = ldl(ssp + 4) & 0xffff;
new_eip = ldl(ssp) & 0xffff;
} else {
/* 16 bits */
new_eflags = lduw(ssp + 4);
new_cs = lduw(ssp + 2);
new_eip = lduw(ssp);
}
new_esp = sp + (6 << shift);
env->regs[R_ESP] = (env->regs[R_ESP] & 0xffff0000) |
(new_esp & 0xffff);
load_seg_vm(R_CS, new_cs);
env->eip = new_eip;
eflags_mask = FL_UPDATE_CPL0_MASK;
if (shift == 0)
eflags_mask &= 0xffff;
load_eflags(new_eflags, eflags_mask);
}
/* protected mode iret */
void helper_iret_protected(int shift)
{
......
......@@ -953,6 +953,11 @@ void OPPROTO op_ljmp_T0_T1(void)
jmp_seg(T0 & 0xffff, T1);
}
void OPPROTO op_iret_real(void)
{
helper_iret_real(PARAM1);
}
void OPPROTO op_iret_protected(void)
{
helper_iret_protected(PARAM1);
......
......@@ -52,6 +52,7 @@ typedef struct DisasContext {
static state change (stop translation) */
/* current block context */
uint8_t *cs_base; /* base of CS segment */
int pe; /* protected mode */
int code32; /* 32 bit code segment */
int ss32; /* 32 bit stack segment */
int cc_op; /* current CC operation */
......@@ -989,7 +990,7 @@ static void gen_lea_modrm(DisasContext *s, int modrm, int *reg_ptr, int *offset_
if (base >= 0) {
/* for correct popl handling with esp */
if (base == 4 && s->popl_esp_hack)
disp += 4;
disp += s->popl_esp_hack;
gen_op_movl_A0_reg[base]();
if (disp != 0)
gen_op_addl_A0_im(disp);
......@@ -1272,7 +1273,7 @@ static void gen_setcc(DisasContext *s, int b)
/* move T0 to seg_reg and compute if the CPU state may change */
static void gen_movl_seg_T0(DisasContext *s, int seg_reg, unsigned int cur_eip)
{
if (!s->vm86)
if (s->pe && !s->vm86)
gen_op_movl_seg_T0(seg_reg, cur_eip);
else
gen_op_movl_seg_T0_vm(offsetof(CPUX86State,segs[seg_reg]));
......@@ -1855,7 +1856,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
gen_op_ld_T1_A0[ot]();
gen_op_addl_A0_im(1 << (ot - OT_WORD + 1));
gen_op_lduw_T0_A0();
if (!s->vm86) {
if (s->pe && !s->vm86) {
/* we compute EIP to handle the exception case */
gen_op_jmp_im(pc_start - s->cs_base);
gen_op_ljmp_T0_T1();
......@@ -2036,7 +2037,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
ot = dflag ? OT_LONG : OT_WORD;
modrm = ldub(s->pc++);
gen_pop_T0(s);
s->popl_esp_hack = 1;
s->popl_esp_hack = 2 << dflag;
gen_ldst_modrm(s, modrm, ot, OR_TMP0, 1);
s->popl_esp_hack = 0;
gen_pop_update(s);
......@@ -2082,6 +2083,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
gen_pop_T0(s);
gen_movl_seg_T0(s, b >> 3, pc_start - s->cs_base);
gen_pop_update(s);
/* XXX: if reg == SS, inhibit interrupts/trace */
break;
case 0x1a1: /* pop fs */
case 0x1a9: /* pop gs */
......@@ -2134,21 +2136,24 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
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 || reg == R_CS)
goto illegal_op;
gen_ldst_modrm(s, modrm, OT_WORD, OR_TMP0, 0);
gen_movl_seg_T0(s, reg, pc_start - s->cs_base);
/* XXX: if reg == SS, inhibit interrupts/trace */
break;
case 0x8c: /* mov Gv, seg */
ot = dflag ? OT_LONG : OT_WORD;
modrm = ldub(s->pc++);
reg = (modrm >> 3) & 7;
mod = (modrm >> 6) & 3;
if (reg >= 6)
goto illegal_op;
gen_op_movl_T0_seg(reg);
ot = OT_WORD;
if (mod == 3 && dflag)
ot = OT_LONG;
gen_ldst_modrm(s, modrm, ot, OR_TMP0, 1);
break;
......@@ -2938,7 +2943,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
break;
case 0x6c: /* insS */
case 0x6d:
if (s->cpl > s->iopl || s->vm86) {
if (s->pe && (s->cpl > s->iopl || s->vm86)) {
/* NOTE: even for (E)CX = 0 the exception is raised */
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
......@@ -2955,7 +2960,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
break;
case 0x6e: /* outsS */
case 0x6f:
if (s->cpl > s->iopl || s->vm86) {
if (s->pe && (s->cpl > s->iopl || s->vm86)) {
/* NOTE: even for (E)CX = 0 the exception is raised */
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
......@@ -2975,7 +2980,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
/* port I/O */
case 0xe4:
case 0xe5:
if (s->cpl > s->iopl || s->vm86) {
if (s->pe && (s->cpl > s->iopl || s->vm86)) {
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
if ((b & 1) == 0)
......@@ -2990,7 +2995,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
break;
case 0xe6:
case 0xe7:
if (s->cpl > s->iopl || s->vm86) {
if (s->pe && (s->cpl > s->iopl || s->vm86)) {
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
if ((b & 1) == 0)
......@@ -3005,7 +3010,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
break;
case 0xec:
case 0xed:
if (s->cpl > s->iopl || s->vm86) {
if (s->pe && (s->cpl > s->iopl || s->vm86)) {
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
if ((b & 1) == 0)
......@@ -3019,7 +3024,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
break;
case 0xee:
case 0xef:
if (s->cpl > s->iopl || s->vm86) {
if (s->pe && (s->cpl > s->iopl || s->vm86)) {
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
if ((b & 1) == 0)
......@@ -3076,7 +3081,11 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
val = 0;
goto do_lret;
case 0xcf: /* iret */
if (s->vm86 && s->iopl != 3) {
if (!s->pe) {
/* real mode */
gen_op_iret_real(s->dflag);
s->cc_op = CC_OP_EFLAGS;
} else if (s->vm86 && s->iopl != 3) {
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
} else {
if (s->cc_op != CC_OP_DYNAMIC)
......@@ -3142,7 +3151,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
/* change cs and pc */
gen_op_movl_T0_im(selector);
if (!s->vm86) {
if (s->pe && !s->vm86) {
/* we compute EIP to handle the exception case */
gen_op_jmp_im(pc_start - s->cs_base);
gen_op_movl_T1_im(offset);
......@@ -3442,6 +3451,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
}
}
/* XXX: interruptions are enabled only the first insn after sti */
break;
case 0x62: /* bound */
ot = dflag ? OT_LONG : OT_WORD;
......@@ -3628,7 +3638,7 @@ long disas_insn(DisasContext *s, uint8_t *pc_start)
break;
case 0x102: /* lar */
case 0x103: /* lsl */
if (s->vm86)
if (!s->pe || s->vm86)
goto illegal_op;
ot = dflag ? OT_LONG : OT_WORD;
modrm = ldub(s->pc++);
......@@ -4106,19 +4116,26 @@ static inline int gen_intermediate_code_internal(CPUState *env,
cs_base = (uint8_t *)tb->cs_base;
flags = tb->flags;
dc->pe = env->cr[0] & CR0_PE_MASK;
dc->code32 = (flags >> GEN_FLAG_CODE32_SHIFT) & 1;
dc->ss32 = (flags >> GEN_FLAG_SS32_SHIFT) & 1;
dc->addseg = (flags >> GEN_FLAG_ADDSEG_SHIFT) & 1;
dc->f_st = (flags >> GEN_FLAG_ST_SHIFT) & 7;
dc->vm86 = (flags >> GEN_FLAG_VM_SHIFT) & 1;
dc->cpl = (flags >> GEN_FLAG_CPL_SHIFT) & 3;
/* CPL is implicit if real mode or vm86 mode */
if (!dc->pe)
dc->cpl = 0;
else if (dc->vm86)
dc->cpl = 3;
else
dc->cpl = (flags >> GEN_FLAG_CPL_SHIFT) & 3;
dc->iopl = (flags >> GEN_FLAG_IOPL_SHIFT) & 3;
dc->tf = (flags >> GEN_FLAG_TF_SHIFT) & 1;
dc->cc_op = CC_OP_DYNAMIC;
dc->cs_base = cs_base;
dc->tb = tb;
dc->popl_esp_hack = 0;
gen_opc_ptr = gen_opc_buf;
gen_opc_end = gen_opc_buf + OPC_MAX_SIZE;
gen_opparam_ptr = gen_opparam_buf;
......@@ -4270,13 +4287,14 @@ void cpu_x86_close(CPUX86State *env)
/* called when cr3 or PG bit are modified */
static int last_pg_state = -1;
static int last_pe_state = 0;
int phys_ram_size;
int phys_ram_fd;
uint8_t *phys_ram_base;
void cpu_x86_update_cr0(CPUX86State *env)
{
int pg_state;
int pg_state, pe_state;
void *map_addr;
#ifdef DEBUG_MMU
......@@ -4304,6 +4322,11 @@ void cpu_x86_update_cr0(CPUX86State *env)
}
last_pg_state = pg_state;
}
pe_state = env->cr[0] & CR0_PE_MASK;
if (last_pe_state != pe_state) {
tb_flush();
last_pe_state = pe_state;
}
}
void cpu_x86_update_cr3(CPUX86State *env)
......
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