asusslic.asm

%include "386scd.inc"
%define SLICPTR    08c00h        ;256字节对齐
;;auto search RSDT ptr
[bits 16]
segment .text align=16

start:         
        xor     dx,dx
                mov     ax,data
                mov     ds,ax
        mov    ax,stack
        mov    ss,ax
                ;准备要加载到GDTR的伪描述符
                mov     bx,16
                mul     bx
                add     ax, GDT              ;计算并设置基地址
                adc     dx,0                       ;界限已在定义时设置好
                mov     [VGDTR+2],ax
                mov     [VGDTR+4],dx
                ;设置代码段描述符
                mov     ax,cs
                mul     bx
                mov     [Code+2],ax         ;代码段开始偏移为0
                mov     [Code+4],dl         ;代码段界限已在定义时设置好
                mov     [Code+7],dh
                ;设置Buff数据段描述符
                mov     ax,ds
                mul     bx                         ;计算并设置Buff数据段基址
                add     ax,Buffer    
                adc     dx,0
                mov     [DataBuff+2],ax
                mov     [DataBuff+4],dl
                mov     [DataBuff+7],dh
                ;设置SLIC数据段描述符
                mov     ax,ds
                mul     bx                         ;计算并设置SLIC数据段基址
                add     ax,SLIC
                adc     dx,0
                mov     [DataSLIC+2],ax
                mov     [DataSLIC+4],dl
                mov     [DataSLIC+7],dh
                ;设置数据段描述符
                mov     ax,ds
                mul     bx                         ;计算并设置数据段基址
                mov     [Data+2],ax
                mov     [Data+4],dl
                mov     [Data+7],dh
                ;SEARCH RSD PTR IN BIOS
                mov     ebx,20000h                 ;bios length=20000h
                mov     ax,0f000h
                mov     es,ax
s1:             cmp     ebx,10000h
                jnz     s2
                mov     ax,0e000h
                mov     es,ax
s2:             sub     ebx,16
                cmp     dword [es:bx],'RSD '
                jz      f1
                jmp     nf1
f1:             cmp     dword [es:bx+4], 'PTR '
                jz      s1_found
nf1:            cmp     ebx,0
                jnz     s1
                jmp     exit            ;no RSD PTR in bios
s1_found:       
                ;设置Buff数据段描述符
                mov     eax,dword [es:bx+16]
                mov     [DataRSDT+2],ax
                mov     dword [RSDTPTR],eax     ;save to RSDTPTR
                shr     eax,16
                mov     [DataRSDT+4],al
                mov     [DataRSDT+7],ah         ;计算并设置RSDT数据段基址
                
                ;加载GDTR
                lgdt    [VGDTR]
                cli                            ;关中断
                EnableA20                      ;打开地址线A20
                ;切换到保护方式
                mov     eax,cr0
                or      al,1
                mov     cr0,eax
                ;清指令预取队列,并真正进入保护方式
                JUMP16  Code_Sel,Virtual
Virtual:        ;现在开始在保护方式下运行
                mov     ax,DataRSDT_Sel
                mov     ds,ax                  ;加载源数据段描述符
                mov     ax,DataBuff_Sel
                mov     es,ax                  ;加载目标数据段描述符
                cld
                xor     si,si
                xor     di,di                  ;设置指针初值
                mov     cx,BufLen/4            ;设置4字节为单位的缓冲区长度
                repz    movsd                  ;传送
                call    dispbuff               ;debug   
                mov     ax,Data_Sel
                mov     fs,ax
                mov     edx,dword [fs:RSDTPTR]   ;restore rsdtptr
                
                mov     bx,36
                mov     cx,[4]
searchslic1:    cmp     bx,cx                    ;设置slic指针初值
                jz      noslic
                cmp     dword [bx],edx
                jl      searchslic2
                mov     edi,dword [bx]
                mov     eax,edi
                sub     edi,edx
                cmp     dword [edi],'SLIC'
                jz      hasslic
searchslic2:    add     bx,4
                jmp     searchslic1
noslic:         mov     eax,SLICPTR
                add     eax,edx
                mov     dword [bx],eax
                add     bx,4
                mov     [4],bx
                mov     di,SLICPTR
hasslic:        mov     ax,DataSLIC_Sel
                mov     ds,ax                  ;加载源数据段描述符
                mov     ax,DataRSDT_Sel
                mov     es,ax                  ;加载目标数据段描述符
                cld
        mov    cx,14/2            ;设置2字节为单位的缓冲区长度
        mov    si,0ah            ;6byte OEM id+8byte Table id
                push    di            ;must equal with the one in slic
                mov     di,0ah                 
                repz    movsw
                xor     si,si                  ;设置指针初值
                pop     di
                mov     cx,SLICLen/4           ;设置4字节为单位的缓冲区长度
                repz    movsd                  ;传送
                    
exitreal:       ;切换回实模式
                mov     eax,cr0
                and     al,11111110b
                mov     cr0,eax
                ;清指令预取队列,进入实方式
                JUMP16  seg Real,Real
dispbuff:    push ax
        push cx
        push es
        push ds
        push si
        push di
        mov ax,DataBuff_Sel
        mov ds,ax
        mov ax,DataVBuf_Sel
        mov es,ax
        xor si,si
        mov di,320
        mov cx,BufLen
movtoVRAM:    mov al,[ds:si]
        mov [es:di],al
        inc si
        inc di
        inc di
        loop movtoVRAM
        pop di
        pop si
        pop ds
        pop es
        pop cx
        pop ax
        ret
Real:           ;现在又回到实方式
                DisableA20
                sti
exit:           mov     ax,4c00h
                int     21h

segment data align=16

GDT:                                  ;全局描述符表
DUMMY:           Desc    0,0,0                    ;空描述符
Code :           Desc    0,0ffffh,ATCE     ;代码段描述符
DataSLIC:        Desc    0,0ffffh,ATDW        ;SLIC数据段描述符
DataBuff:        Desc    0,0ffffh,ATDW         ;Buff数据段描述符
DataVBuf:     Desc     0b8000h,0ffffh,ATDW    ;显示缓冲数据段描述符    
DataRSDT:        Desc    0,0ffffh,ATDW         ;RSDT数据段描述符
Data:            Desc    0,0ffffh,ATDW     ;数据段描述符
;----------------------------------------------------------------------------
GDTLen          equ       $-GDT                 ;全局描述符表长度
VGDTR:           PDesc   0,GDTLen-1           ;伪描述符
;----------------------------------------------------------------------------
Code_Sel        equ       Code-GDT              ;代码段选择子
DataSLIC_Sel       equ       DataSLIC-GDT             ;SLIC数据段选择子
DataBuff_Sel       equ      DataBuff-GDT             ;Buff数据段选择子
DataVBuf_Sel     equ     DataVBuf-GDT    ;显示缓冲数据段选择子    
DataRSDT_Sel    equ      DataRSDT-GDT          ;RSDT Selector
Data_Sel        equ     Data-GDT                ;Data 段选择子
;----------------------------------------------------------------------------
RSDTPTR         dd      0       ;RSDTPTR
SLIC:
db    053h, 04Ch, 049h, 043h, 076h, 001h, 000h, 000h, 001h, 04Bh, 05Fh, 041h
db    053h, 055h, 053h, 05Fh, 04Eh, 06Fh, 074h, 065h, 062h, 06Fh, 06Fh, 06Bh
db    024h, 006h, 000h, 011h, 04Dh, 053h, 046h, 054h, 097h, 000h, 000h, 000h
db    000h, 000h, 000h, 000h, 09Ch, 000h, 000h, 000h, 006h, 002h, 000h, 000h
db    000h, 024h, 000h, 000h, 052h, 053h, 041h, 031h, 000h, 004h, 000h, 000h
db    001h, 000h, 001h, 000h, 06Fh, 092h, 09Dh, 0DCh, 0B3h, 079h, 0EEh, 027h
db    026h, 008h, 0F8h, 0DCh, 05Bh, 0D8h, 05Fh, 04Bh, 021h, 034h, 0ABh, 060h
db    0ECh, 090h, 0C7h, 0C2h, 0D5h, 060h, 0D5h, 0F5h, 0D9h, 082h, 0F9h, 02Eh
db    0BEh, 0E8h, 043h, 038h, 0D5h, 0C2h, 05Bh, 09Eh, 025h, 0B8h, 093h, 0CDh
db    015h, 0B8h, 01Bh, 0C3h, 030h, 07Dh, 0ADh, 055h, 069h, 079h, 0BDh, 01Ah
db    07Eh, 044h, 0C8h, 0BCh, 059h, 05Ah, 017h, 0BEh, 081h, 0ADh, 0EFh, 0EEh
db    096h, 021h, 037h, 0CCh, 08Ah, 042h, 062h, 0C6h, 014h, 005h, 009h, 021h
db    069h, 07Ah, 0E1h, 08Ch, 04Ah, 0CEh, 0D6h, 0C8h, 018h, 078h, 078h, 086h
db    02Bh, 030h, 063h, 0A6h, 0E5h, 064h, 0B7h, 0D2h, 014h, 05Eh, 02Bh, 044h
db    0BEh, 033h, 012h, 06Bh, 06Bh, 0A3h, 0BDh, 09Eh, 085h, 0BBh, 0BEh, 06Ch
db    0E1h, 0B1h, 033h, 0C2h, 0DAh, 091h, 080h, 0F3h, 044h, 0B4h, 0CAh, 09Fh
db    001h, 000h, 000h, 000h, 0B6h, 000h, 000h, 000h, 000h, 000h, 002h, 000h
db    05Fh, 041h, 053h, 055h, 053h, 05Fh, 04Eh, 06Fh, 074h, 065h, 062h, 06Fh
db    06Fh, 06Bh, 057h, 049h, 04Eh, 044h, 04Fh, 057h, 053h, 020h, 000h, 000h
db    000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db    000h, 000h, 000h, 000h, 000h, 000h, 024h, 0B0h, 089h, 0CFh, 0B1h, 0F3h
db    01Dh, 0B8h, 07Ah, 080h, 035h, 0CBh, 0CDh, 04Ah, 0C8h, 02Fh, 084h, 0CEh
db    099h, 0A0h, 04Fh, 038h, 076h, 0B0h, 004h, 0F9h, 06Fh, 005h, 033h, 0C7h
db    0ECh, 0A8h, 058h, 0A6h, 0D7h, 0B7h, 03Fh, 05Bh, 082h, 0B1h, 0EEh, 02Bh
db    0A7h, 081h, 052h, 0F3h, 045h, 013h, 0CEh, 0EEh, 0D5h, 057h, 037h, 0FEh
db    075h, 05Fh, 05Ch, 062h, 0C4h, 053h, 0DAh, 086h, 0F1h, 034h, 0FAh, 0EDh
db    091h, 086h, 073h, 09Eh, 0D2h, 065h, 0FDh, 08Ah, 03Dh, 086h, 094h, 02Fh
db    02Ah, 065h, 018h, 05Ch, 0D9h, 0E5h, 07Ch, 015h, 01Eh, 0F2h, 008h, 0C5h
db    085h, 0C4h, 08Fh, 00Bh, 0FAh, 0A5h, 0C3h, 0A9h, 0B0h, 0F1h, 0B2h, 0E7h
db    06Ah, 046h, 0FBh, 018h, 001h, 05Dh, 04Ch, 036h, 033h, 0DEh, 0FBh, 0E7h
db    01Dh, 0E8h, 015h, 0C2h, 085h, 09Fh, 08Ah, 0A9h, 032h, 068h, 01Fh, 0B4h
db    0BCh, 0A8h
db    0,0
SLICLen          equ      $-SLIC                  ;SLIC字节长度
BufLen        equ    2048
Buffer:         times   BufLen  db      30

segment stack stack
times 128 db 0