NASM汇编编译器--开源

;GoodFlag1 equ 0bh ;HideFlag1 equ 1bh ;GoodFlag2 equ 0ch ;HideFlag2 equ 1ch ;GoodFlag3 equ 0eh ;HideFlag3 equ 1eh ORIGIN EQU 7C00H ; Origin of bootstrap LOADER BIO_MEM EQU 0413H ; BIOS Memory size =640(KB) BIO_CLK EQU 046CH ; BIOS Clock (1/18.2 seconds) DSK_PARMS EQU 1EH*4 ;POINTER TO DRIVE PARAMETERS KEY_BOOTHIDDEN EQU 41H ;Scancode: F7=41H, F11=85H, F12=86H KEY_BOOTFLOPPY EQU 3FH ;Scancode: F5=3FH KEY_ESCAPE EQU 01H ;Scancode: ESC=01H BOOTHIDDENFLAG EQU 80h ORG 0000h START: ; WARNING -- Don change this to a short jmp jmp short main ; Jump to start of code nop ; ========================================================================== ; Start of BPB area of the boot record OemName DB "MSDOS" OsVersion DB "5.0" ; DOS version number BPB: BytesPerSector DW 512 ; Size of a physical sector SecsPerClust DB 1 ; Sectors per allocation unit ReservedSecs DW 1 ; Number of reserved sectors NumFats DB 2 ; Number of fats NumDirEntries DW 00E0h ; Number of direc entries TotalSectors DW 0B40H ; Number of sectors - number of hidden ; sectors (0 when 32 bit sector number) MediaByte DB 0F0H ; MediaByte byte NumFatSecs DW 9 ; Number of fat sectors SecPerTrack DW 18 ; Sectors per track NumHeads DW 2 ; Number of drive heads HiddenSecs DD 0 ; Number of hidden sectors BigTotalSecs DD 0 ; 32 bit version of number of sectors BootDrv DB 0h CurrentHead DB 0h ; Current Head ExtBootSig DB 41 SerialNum DD 20050628h VolumeLabel DB "YISIR_LOADER" FatId DB "FAT12" ; ========================================================================= ; First thing is to reset the stack to a better and more known ; place. The ROM may change, but wed like to get the stack ; in the correct place. main: cli ;Stop interrupts till stack ok xor AX,AX mov ds,ax mov es,ax mov SS,AX ;Work in stack just below this routine mov ax,ORIGIN mov sp,ax sti PUSH AX ;Show message mov ax,1301h mov bx,000ah mov cx,MyMsgLen mov dx,1500h mov bp,MyMsg+ORIGIN int 10h ;Hide the cursor mov ah,1 mov cx,2000h int 10h ;Wait 10 seconds mov si, BIO_CLK mov edx, dword [si] mov ecx, edx add edx, 159 ;18.2*10 seconds ReadKB: ;Change 5 bytes with install option ;Case Option: /f Boot from floppy disk directly, do not waiting 8 seconds ;31H D2H xor dx,dx ;E9H xxH 00H jmp BiosMemory ; ;Case Option: /b Boot from HIDDEN parition derectly (activate it and load it) ;31H D2H xor dx,dx ;E9H xxH 00H jmp Key_F7 ; ;Case Default: Show message and wait 8 second mov ah, 11h ;Get keyboard status int 16h jz NoKeyPress mov ah,10h ;Read a key (In old code, AH=0, can not read F11/F12...) int 16h xor dx,dx cmp ah, KEY_ESCAPE jz DX_HD ;Press ESC to BOOT from Harddisk cmp ah, KEY_BOOTFLOPPY jnz RKB_1 mov dh, 0ffh ;dh=0 Install INT13, else do not Install. Now DX=FF00H jmp BiosMemory RKB_1: cmp ah, KEY_BOOTHIDDEN jnz BiosMemory Key_F7: ;If press Hot key, Boot From Hidden Partition. Now DX=0001H ;modify CH=80h in Int13 procedure mov byte[ORIGIN+2+BootHiddenCode], BOOTHIDDENFLAG jmp DX_HD NoKeyPress: cmp ecx, dword [si] jae L_0 test cl,1 jz L_0 mov ax,0e3eh ; write ">" to show progressing mov bx,0004h int 10h L_0: mov ecx, dword [si] cmp edx,ecx jae ReadKB mov dh,0ffh ;Do not install INT13. Now DX=FF00 DX_HD: mov dl,080h ;Boot from HD. ;DH=0 Install INT13, DH=FFH do not Install ;DL=0 Boot Floppy, DL=80H Boot HD ;Now: ; ESC DX=FF80, F5 DX=FF00H, F7 DX=0080H, ANYKEY DX=0000H, TIMEOUT DX=FF80H BiosMemory: ;Show the cursor mov ah,1 mov cx,0d0eh int 10h ;BIOS MEMORY - 2KB mov bx,BIO_MEM ;bx=280H (KB) mov ax,word [bx] dec ax cmp dh,0 jnz L_1 mov word [bx],ax ;If DH=FF, Do not install L_1: ;Move to High Memory. ex. 9fc0:0000 shl ax,6 ;ax=9fc0h SEG of top memory mov es,ax ;es=9fc0h pop si ;si=7c00h push es ;ready to RETF xor di,di ;di=0 cld mov cx,100h repnz movsw ;move code to 9fc0:0000 cmp dh,0 jnz L_2 ;If DH=0ffh, Do not install ;modify Int13 mov si,4ch ;Int13 13h*4 mov di,OLDINT13 ;Save Old mov eax,[si] mov [es:di],eax ; cmp dh,0 ; jnz L_2 ;If DH=0ffh, Do not install push es pop ax shl eax,16 mov ax, MyInt13 mov [si],eax L_2: ;Jump to high address, 9fc0:00xx push ds pop es mov bx,word Entre2 push bx ;push 9fc0:Entre2 retf ;跳到高端执行 Entre2: cmp dl,0 ;If DX <> 0, Load HD-MBR jnz L_3 ReadFD: ;Read old boot sector from Floppy H1 T79 S18 mov cx,4f12h mov dx,0100h jmp RunInt13 L_3: ;Read from Harddisk H0 T0 S1 MBR mov cx,1 mov dx,80h RunInt13: mov ax,0201h mov bx,ORIGIN push ds push bx int 13h retf ; 2005-9-1 ; 这里是原来用的花哨技巧代码，就是它们导致使用F7启动不了隐藏分区。因为这里读到的是原始的MBR ; pushf ;int 13h ; push ds ; push bx ; ------------------------------------------ ;Jump to Old INT 13H JmpFarInt13: DB 0eah ;JMP far OLDINT13 OLDINT13 DW 0,0 ;End of Install-code ;Partition Flag Table normal and hidden FlagTable: dw 0111h, 0414h, 0616h, 0717h, 0b1bh, 0c1ch, 0e1eh FlagTableEnd: ;My INT13h code MyInt13: cmp ah,2 ;Is Read? jz Func2 cmp ah,42h ;Is ExtRead? jz Func42 JmpOldInt13: jmp JmpFarInt13 Func2: CMP DX,0080H ;Is Harddisk and Head 0? jnz JmpOldInt13 cmp cx,0001H ;Is Track 0 Sector 1? jnz JmpOldInt13 pushf ;Simulate INT operator push cs CALL JmpFarInt13 ;Call old INT13 jc exit ;Flase then Exit push bx push es jmp EditFlag Func42: cmp dl,80h ;Is Harddisk jnz JmpOldInt13 push eax xor eax,eax cmp dword [si+8],eax ;Is Sector 0, Low 32bit jnz ExitFunc42 cmp dword [si+12],eax ;Is Sector 0, Hight 32bit jnz ExitFunc42 pop eax pushf ;Simulate INT operator push cs CALL JmpFarInt13 ;Call old INT13 jc exit ;If flase then Exit push bx push es mov bx, [si+4] ; Fix BX,ES like Int13h Func02 mov es, [si+6] jmp EditFlag ExitFunc42: pop eax jmp JmpOldInt13 EditFlag: push ax push cx push si