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fix protection fault from GDT

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Hojun-Cho 2024-12-07 01:14:26 +09:00
parent 11097add40
commit 8336f11b2a
1 changed files with 25 additions and 26 deletions
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51
boot/gdt.S
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@ -2,6 +2,16 @@
#include "def.h" #include "def.h"
#define AX 0
#define CX 4
#define DX 8
#define BX 12
#define BP 16
#define SI 20
#define DI 24
#define DS 28
#define ES 32
#define GEN_LABEL(n) X##n #define GEN_LABEL(n) X##n
// idt entry // idt entry
@ -63,22 +73,12 @@
\ \
lidt Idtr; lidt Idtr;
.text
.globl BIOSreg
BIOSreg:
BIOS_AX: .long 0
BIOS_CX: .long 0
BIOS_DX: .long 0
BIOS_BX: .long 0
BIOS_BP: .long 0
BIOS_SI: .long 0
BIOS_DI: .long 0
BIOS_DS: .long 0
BIOS_ES: .long 0
.text .text
.code32 .code32
.globl pmode_init .globl pmode_init
.globl BIOSreg
BIOSreg:
.space 64
// Table // Table
// IDTR offset + 0 : entry 0 // IDTR offset + 0 : entry 0
@ -246,11 +246,9 @@ EMUh: // build stack for real mode
movb %al, intno // save BIOS int vector movb %al, intno // save BIOS int vector
// BIOS_regs is area for saving the contents of registers returned by the BIOS during a BIOS CALL // BIOS_regs is area for saving the contents of registers returned by the BIOS during a BIOS CALL
movl BIOS_ES, %eax movl BIOSreg+ES, %eax
movl $0x00, %eax
mov %eax, 7f mov %eax, 7f
movl BIOS_DS, %eax movl BIOSreg+DS, %eax
movl $0x00, %eax
mov %eax, 6f mov %eax, 6f
prot2real prot2real
@ -300,12 +298,13 @@ intno = . -1;
// movl $Leax, %eax // movl $Leax, %eax
.byte 0xb8 .byte 0xb8
4: .long 0x90909090 4: .long 0x90909090
mov %eax, BIOS_BX movl %eax, BIOSreg+BX
// movl $Leax, %eax // movl $Leax, %eax
.byte 0xb8 .byte 0xb8
3: .long 0x90909090 3: .long 0x90909090
mov %eax, BIOS_ES movl %eax, BIOSreg+ES
// movl $Leax, %eax // movl $Leax, %eax
.byte 0xb8 .byte 0xb8
@ -318,13 +317,13 @@ intno = . -1;
movb %bh, 0xe*4(%esp) // restore eflags movb %bh, 0xe*4(%esp) // restore eflags
// save register into BIOSREG // save register into BIOSREG
.code32 movl %eax, BIOSreg+AX
movl %eax, BIOS_AX movl %ecx, BIOSreg+CX
movl %ecx, BIOS_CX movl %edx, BIOSreg+DX
movl %edx, BIOS_DX movl %ebp, BIOSreg+BP
movl %ebp, BIOS_BP movl %esi, BIOSreg+SI
movl %esi, BIOS_SI movl %edi, BIOSreg+DI
movl %edi, BIOS_DI
// clear NT(Nested Task Flag: 14) flag in eflag // clear NT(Nested Task Flag: 14) flag in eflag
// if 1 : interrupting // if 1 : interrupting