732 lines
15 KiB
NASM
732 lines
15 KiB
NASM
[BITS 16]
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[ORG 0x100]
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SECTION .text
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push cs
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push cs
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pop ds
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pop es
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mov si,msg0
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call showstr
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mov si,msg1
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call showstr
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call initfat
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call ok
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mov si,msg2
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call showstr
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mov si,System_File
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call search
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call ok
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mov si,msg3
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call showstr
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call EnableA20
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call ok
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mov si,msg4
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call showstr
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mov eax,cs
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shl eax,4
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mov [GDT.Entry1+2],ax
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mov [GDT.Entry2+2],ax
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shr eax,16
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mov [GDT.Entry1+4],al
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mov [GDT.Entry2+4],al
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mov eax,cs
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shl eax,4
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add eax,gdt0
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mov [GDTR.Address],eax
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lgdt [GDTR]
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call ok
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mov si,msg5
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call showstr
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cli
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mov eax,cr0
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or al,1
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mov cr0,eax
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jmp short $+2
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mov bx,SYS_DATA_SEL
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mov fs,bx
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mov ds,bx
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mov es,bx
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mov gs,bx
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and al,0FEh
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mov cr0,eax
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jmp short $+2
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mov bx,cs
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mov fs,bx
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mov ds,bx
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mov es,bx
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mov gs,bx
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sti
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call ok
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mov si,msg6
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call showstr
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mov ebx,0x300000
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call load
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call ok
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mov si,msg7
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call showstr
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call initpe
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call ok
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mov si,msg8
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call showstr
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cli
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mov al,0x80
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out 0x70,al
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mov eax,cr0
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or al,1
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mov cr0,eax
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jmp SYS_CODE_SEL:GoPMode32
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Boot_Error:
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mov si,error
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call showstr
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xor ax,ax
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int 16h
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jmp 0xFFFF:0x0
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ok:
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push si
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push cx
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mov cl,67
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call eol
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mov si,okay
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call showstr
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pop cx
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pop si
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ret
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;======================INITPE========================
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;Initialise le PE de l'adresse EBX
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;->
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;<- Flag Carry si erreur
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;=====================================================
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initpe:
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pusha
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push es
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xor ax,ax
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mov es,ax
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mov [begin],ebx
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cmp word [es:ebx+mzheader.magic],"MZ" ; bien l'entete .exe dos ?
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jne near errorpe
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add ebx,[es:ebx+mzheader.lfanew] ; Pointe vers l'entete PE
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cmp word [es:ebx+peheader.Signature],"PE" ; bien l'entete PE ?
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jne near errorpe
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cmp word [es:ebx+peheader.Signature+2],0 ; bien l'entete PE ?
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jne near errorpe
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mov [p_pe],ebx
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mov esi,[es:ebx+peheader.ImageBase]
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mov [base],esi
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add esi,[es:ebx+peheader.AddressOfEntryPoint]
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mov [entriepoint],esi
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mov ax,[es:ebx+peheader.NumberOfSections]
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add ebx,peheader.end
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mov [p_sections],ebx
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mov si,info1
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call showstr
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readsections:
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mov si,info2
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call showstr
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mov esi,ebx
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mov cx,8
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call showfixstr
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mov cl,17
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call eol
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mov edx,[es:ebx+sections.VirtualAddress]
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add edx,[base]
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mov cx,32
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call ShowHex
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mov cl,30
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call eol
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mov si,info3
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call showstr
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mov edx,[es:ebx+sections.VirtualSize]
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mov cx,32
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call ShowHex
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mov si,info4
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call showstr
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mov edi,[es:ebx+sections.VirtualAddress]
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add edi,[base]
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cmp edi,0
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je noload
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push eax
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push ecx
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mov esi,[es:ebx+sections.PointerToRawData]
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add esi,[begin]
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mov ecx,[es:ebx+sections.SizeOfRawData]
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shr cx,2
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cmp cx,0
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je zeroize
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copietomem:
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mov eax,[es:esi]
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mov [es:edi],eax
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add edi,4
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add esi,4
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dec cx
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jnz copietomem
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pop ecx
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pop eax
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jmp nextsymb
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zeroize:
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mov ecx,[es:ebx+sections.VirtualSize]
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shr cx,2
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mov eax,0
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zerotomem:
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mov [es:edi],eax
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add edi,4
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dec cx
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jnz zerotomem
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pop ecx
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pop eax
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jmp nextsymb
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noload:
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mov si,info5
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call showstr
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nextsymb:
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mov si,return
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call showstr
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add ebx,sections.end
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dec ax
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jnz readsections
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mov si,info6
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call showstr
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mov edx,[entriepoint]
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mov cx,32
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call ShowHex
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clc
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pop es
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popa
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ret
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errorpe:
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stc
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pop es
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popa
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ret
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entriepoint dd 0
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begin dd 0
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base dd 0
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p_pe dd 0
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p_sections dd 0
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;==========SHOWHEX===========
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;Affiche un nombre hexad<61>cimal EDX de taille CX apr<70>s le curseur
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;-> AH=10, EDX un entier, CX la taille
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;<-
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;===========================================
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ShowHex:
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push ax
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push bx
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push cx
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push edx
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mov ax,cx
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shr ax,2
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sub cx,32
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neg cx
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shl edx,cl
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xor cx,cx
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inc cx
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Hexaize:
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rol edx,4
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mov bx,dx
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and bx,0fh
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push ax
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mov al,[cs:bx+Tab]
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xor bx,bx
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mov ah,0x09
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mov bl,[cs:thecolor]
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int 0x10
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mov ah,0x0E
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int 0x10
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pop ax
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dec al
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jnz Hexaize
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pop edx
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pop cx
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pop bx
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pop ax
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ret
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Tab db '0123456789ABCDEF'
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;======================EOL========================
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;Va en colonne CX
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;->
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;<- Flag Carry si erreur
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;=====================================================
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eol:
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pusha
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mov bp,cx
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mov ah,03
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xor bx,bx
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int 10h
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mov ah,02
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mov cx,bp
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mov dl,cl
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int 10h
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popa
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ret
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;======================LOAD========================
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;Charge le groupe en m<>moire en ebx
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;->
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;<- Flag Carry si erreur
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;=====================================================
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load:
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push ax
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push ebx
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push ecx
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push edx
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push esi
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push edi
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push fs
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xor edx,edx
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xor ax,ax
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mov fs,ax
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mov si,The_Dot
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mov dx,[Sectors_Size]
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Resume_Loading:
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cmp cx,0x0FF0
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jae Finish_Loading
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push cx
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add cx,word [data]
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mov edi,Buffer
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call ReadSector
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pop cx
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jc near Boot_Error
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call showstr
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push esi
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push ebx
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push cx
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mov esi,Buffer
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mov cx,dx
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shr cx,2
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copie:
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mov eax,[ds:esi]
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mov [fs:ebx],eax
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add ebx,4
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add esi,4
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dec cx
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jnz copie
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pop cx
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pop ebx
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pop esi
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add ebx,edx
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call NextFatGroup
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jc near Boot_Error
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jmp Resume_Loading
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Finish_Loading:
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pop fs
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pop edi
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pop esi
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pop edx
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pop ecx
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pop ebx
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pop ax
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ret
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;======================INITFAT========================
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;Initialise les variables de la fat
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;->
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;<- Flag Carry si erreur
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;=====================================================
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initfat:
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pusha
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push ds
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xor ax,ax
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mov ds,ax
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mov si,0x7C0B
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mov di,bootsector
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mov cx, 512
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rep movsb
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pop ds
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mov cx,[Reserved_Sectors]
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add cx,[Sectors_Hidden]
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adc cx,[Sectors_Hidden+2]
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mov bx,[Sectors_Per_Fat]
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mov di,Fat_Buffer
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push bx
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push cx
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readfat:
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call ReadSector
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jc Boot_Error
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inc cx
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add di,[Sectors_Size]
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dec bx
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jnz readfat
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pop cx
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pop bx
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xor ax,ax
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mov al,[Fats_Number]
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mul bx
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add cx,ax
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mov [entries],cx
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mov ax,32
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mul word [Fits_Number]
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div word [Sectors_Size]
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add cx,ax
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sub cx,2
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mov word [data],cx
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popa
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ret
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;======================SEARCH========================
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;Recherche le groupe d'un fichier
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;-> si nom du fichier
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;<- Flag Carry si erreur CX
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;=====================================================
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search:
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push bx
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push dx
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push di
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mov cx,[entries]
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mov di,Buffer
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call ReadSector
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jc Boot_Error
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xor bx,bx
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Next_Root_Entrie:
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cmp byte [di],0
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je Boot_Error
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push si
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push di
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push cx
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mov cx,11
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rep cmpsb
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pop cx
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pop di
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pop si
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je Found
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add di,32
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add bx,32
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inc dx
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cmp dx,[Fits_Number]
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ja Boot_Error
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cmp bx,[Sectors_Size]
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jb Next_Root_Entrie
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inc cx
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Found:
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mov cx,[di+26]
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pop di
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pop dx
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pop bx
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ret
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;======================SHOWSTR========================
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;Affiche la chaine de caract<63>re point<6E> par ds:si <20> l'<27>cran
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;-> DS, SI
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;<- Flag Carry si erreur
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;=====================================================
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showstr:
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pusha
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xor bh,bh
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xor cx,cx
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inc cx
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nextchar:
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lodsb
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or al,al
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jz endshow
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cmp al,' '
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jb justchar
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cmp al,'#'
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jne nocolor
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lodsb
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sub al,'0'
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shl al,3
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mov [cs:thecolor],al
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shr al,2
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add [cs:thecolor],al
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lodsb
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sub al,'0'
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add [cs:thecolor],al
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jmp nextchar
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nocolor:
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xor bx,bx
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mov ah,0x09
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mov bl,[cs:thecolor]
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int 0x10
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justchar:
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mov ah,0x0E
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int 0x10
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jmp nextchar
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endshow:
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popa
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ret
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;======================SHOWFIXEDSTR========================
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;Affiche la chaine de caract<63>re point<6E> par esi <20> l'<27>cran pour CX caract<63>res
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;-> DS, SI
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;<- Flag Carry si erreur
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;=====================================================
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showfixstr:
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pusha
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push ds
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xor ax,ax
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mov ds,ax
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xor bh,bh
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mov dx,cx
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xor cx,cx
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inc cx
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nextchars:
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mov al,[ds:esi]
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inc esi
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or al,al
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jz endshows
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cmp al,' '
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jb justchars
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xor bx,bx
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mov ah,0x09
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mov bl,[cs:thecolor]
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int 0x10
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justchars:
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mov ah,0x0E
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int 0x10
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dec dx
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jnz nextchars
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endshows:
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pop ds
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popa
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ret
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;====================READSECTOR=======================
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;Lit le secteur logique LBA CX et le met en es:di
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;-> CX (limit<69> <20> 65536 secteurs, soit 32 Mo avec secteur 512 octets)
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;<- Flag Carry si erreur
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;=====================================================
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ReadSector:
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pusha
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mov ax,cx
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xor dx,dx
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div word [Sectors_Per_Track]
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inc dl
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mov bl,dl
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xor dx,dx
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div word [Heads_Number]
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mov dh, [Boot_Drive]
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xchg dl,dh
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mov cx,ax
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xchg cl,ch
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shl cl,6
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or cl, bl
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mov bx,di
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mov si, 4
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mov al, 1
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Read_Again:
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mov ah, 2
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int 0x13
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jnc Read_Done
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dec si
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jnz Read_Again
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Read_Done:
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popa
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ret
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;===================NEXTFATGROUP======================
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;Renvoie en CX le groupe qui succ<63>de dans la FAT le groupe CX
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;-> CX
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;<-
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;=====================================================
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NextFatGroup:
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push bx
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push dx
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push di
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mov ax,cx
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mov bx,ax
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and bx,0000000000000001b
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shr ax,1
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mov cx,3
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mul cx
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mov di,Fat_Buffer
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add di,ax
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cmp bx,0
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jnz Even_Group
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Odd_Group:
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mov dx,[di]
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and dx,0x0FFF
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mov cx,dx
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jmp Next_Group_Found
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Even_Group:
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mov dx,[di+1]
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and dx,0xFFF0
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shr dx,4
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mov cx,dx
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Next_Group_Found:
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pop di
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pop dx
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pop bx
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ret
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;***********************EnableA20*******************************
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;->
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;<-
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;Ouvre l'autoroute A20
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;***************************************************************
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EnableA20:
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cli
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call ClearKeybBuffer
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call WaitKeybCommand
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mov al,0xd1
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out 0x64,al
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call WaitKeybCommand
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mov al,0xdf
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out 0x60,al
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call WaitKeybCommand
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jmp A20Enabled
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WaitKeybCommand:
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in al,0x64
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test al,0x02
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jnz WaitKeybCommand
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ret
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ClearKeybBuffer:
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in al,0x64
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test al,0x01
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jnz ReadKeyb
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ret
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ReadKeyb:
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in al,0x60
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jmp ClearKeybBuffer
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A20Enabled:
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sti
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ret
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GoPMode32:
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[BITS 32]
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mov ax,ALL_DATA_SEL
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mov es,ax
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mov gs,ax
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mov fs,ax
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mov ss,ax
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mov ds,ax
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mov esp,0x3fffff
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push KERNEL_SEL
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push dword [cs:entriepoint]
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retf
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; jmp KERNEL_SEL:0x401020
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section .data
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thecolor db 0x07
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msg0 db '#12-=< Lancement du Chargeur PE >=-',0x0A,0x0D,0x0A,0x0D,0
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msg1 db '#07Initialisation de la FAT',0
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msg2 db '#07Recherche du systeme',0
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msg3 db '#07Activation adressage 24 bits',0
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msg4 db '#07Chargement des descripteurs',0
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msg5 db '#07Passage en mode Flat real',0
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msg6 db '#07Chargement du systeme',0
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msg7 db '#07Mise en place image PE',0
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msg8 db '#07Passage en mode protege',0
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msg9 db '#07Execution du noyau',0
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info1 db 0x0A,0x0D,'#08Sections :',0x0A,0x0D,0
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info2 db ' -',0
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info3 db ' (',0
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info4 db ') ',0
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info5 db ' #12Non projete#08',0
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|
||
info6 db 'Point entree en ',0
|
||
|
||
return db 0x0A,0x0D,0
|
||
|
||
okay db ' #15[ #10OK #15]',0x0A,0x0D,0
|
||
error db ' #15[#12Erreur#15]',0x0A,0x0D,0x0A,0x0D,' <Appuyez une touche pour redemarrer>',0
|
||
The_Dot db '.',0
|
||
System_File db "SYSTEM SYS"
|
||
entries dw 0
|
||
data dw 0
|
||
xy dw 0
|
||
|
||
GDTR:
|
||
.Size: dw GDT_END
|
||
.Address: dd 0
|
||
|
||
gdt0 equ $ ; null entry
|
||
GDT:
|
||
.Entry0: dw 0 ; limit 15:0
|
||
dw 0 ; base 15:0
|
||
db 0 ; base 23:16
|
||
db 0 ; type
|
||
db 0 ; limit 19:16, flags
|
||
db 0 ; base 31:24
|
||
|
||
|
||
SYS_CODE_SEL equ $-gdt0 ; code segment descriptor
|
||
|
||
.Entry1: dw 0xFFFF
|
||
dw 0x0 ; base
|
||
db 0x0 ; base
|
||
db 0x9A ; present, ring 0, code, non-conforming, readable
|
||
db 0xCF ; 32 bit
|
||
db 0
|
||
|
||
|
||
SYS_DATA_SEL equ $-gdt0 ; data segment descriptor
|
||
|
||
.Entry2: dw 0xFFFF
|
||
dw 0x0 ; base
|
||
db 0x0 ; base
|
||
db 0x92 ; present, ring 0, data, expand-up, writable
|
||
db 0xCF ; 32 bit
|
||
db 0
|
||
|
||
|
||
ALL_DATA_SEL equ $-gdt0 ; 4meg data segment descriptor
|
||
|
||
.Entry3: dw 0xFFFF
|
||
dw 0x0 ; base
|
||
db 0x0 ; base
|
||
db 0x92 ; present, ring 0, data, expand-up, writable
|
||
db 0xCF ; 4k pages, 32 bit
|
||
db 0
|
||
|
||
|
||
KERNEL_SEL equ $-gdt0 ; 4g code segment descriptor
|
||
|
||
.Entry4: dw 0xffff
|
||
dw 0x0 ; base
|
||
db 0x0 ; base
|
||
db 0x9A ; present, ring 0, code, non-conforming, readable
|
||
db 0xCF ; 4k pages, 32 bit
|
||
db 0
|
||
|
||
GDT_END equ $-gdt0 -1
|
||
|
||
bootsector equ $
|
||
Sectors_Size dw 0 ;Nombre d'octets/secteur
|
||
Sectors_Per_Cluster db 0 ;Nombre de secteurs/cluster
|
||
Reserved_Sectors dw 0 ;Nombre de secteurs r<>serv<72>
|
||
Fats_Number db 0 ;Nombre de copies de la FAT
|
||
Fits_Number dw 0 ;Taille du r<>pertoire racine
|
||
Sectors_Per_Disk dw 0 ;Nombre secteurs du volume si < 32 Mo
|
||
Media_Descriptor db 0 ;Descripteur de m<>dia
|
||
Sectors_Per_Fat dw 0 ;Nombre secteurs/FAT
|
||
Sectors_Per_Track dw 0 ;Nombre secteurs/piste
|
||
Heads_Number dw 0 ;Nombre de tete de lecture/<2F>criture
|
||
Sectors_Hidden dd 0 ;Nombre de secteurs cach<63>s
|
||
Sectors_Per_Disk2 dd 0 ;Nombre secteurs du volume si > 32 Mo
|
||
Boot_Drive db 0 ;Lecteur de d<>marrage
|
||
Reserved db 0 ;NA (pour NT seulement)
|
||
Extended_Boot_ID db 0 ;Signature Boot <20>tendu 29h
|
||
|
||
Buffer equ $
|
||
Fat_Buffer equ $+512
|
||
|
||
SECTION .bss
|
||
|
||
%include "pe.h"
|
||
|