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Diffstat (limited to 'contrib/syslinux/latest/core/adv.inc')
| -rw-r--r-- | contrib/syslinux/latest/core/adv.inc | 509 |
1 files changed, 0 insertions, 509 deletions
diff --git a/contrib/syslinux/latest/core/adv.inc b/contrib/syslinux/latest/core/adv.inc deleted file mode 100644 index 0b45a6c..0000000 --- a/contrib/syslinux/latest/core/adv.inc +++ /dev/null @@ -1,509 +0,0 @@ -;; ----------------------------------------------------------------------- -;; -;; Copyright 2007-2008 H. Peter Anvin - All Rights Reserved -;; -;; This program is free software; you can redistribute it and/or modify -;; it under the terms of the GNU General Public License as published by -;; the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, -;; Boston MA 02110-1301, USA; either version 2 of the License, or -;; (at your option) any later version; incorporated herein by reference. -;; -;; ----------------------------------------------------------------------- - -;; -;; adv.inc -;; -;; The auxillary data vector and its routines -;; -;; The auxillary data vector is a 512-byte aligned block that on the -;; disk-based derivatives can be part of the syslinux file itself. It -;; exists in two copies; when written, both copies are written (with a -;; sync in between, if from the operating system.) The first two -;; dwords are magic number and inverse checksum, then follows the data -;; area as a tagged array similar to BOOTP/DHCP, finally a tail -;; signature. -;; -;; Note that unlike BOOTP/DHCP, zero terminates the chain, and FF -;; has no special meaning. -;; - -;; -;; List of ADV tags... -;; -ADV_BOOTONCE equ 1 - -;; -;; Other ADV data... -;; -ADV_MAGIC1 equ 0x5a2d2fa5 ; Head signature -ADV_MAGIC2 equ 0xa3041767 ; Total checksum -ADV_MAGIC3 equ 0xdd28bf64 ; Tail signature - -ADV_LEN equ 500 ; Data bytes - -adv_retries equ 6 ; Disk retries - - section .adv - ; Introduce the ADVs to valid but blank -adv0: -.head resd 1 -.csum resd 1 -.data resb ADV_LEN -.tail resd 1 -.end equ $ -adv1: -.head resd 1 -.csum resd 1 -.data resb ADV_LEN -.tail resd 1 -.end equ $ - section .text16 - - ; - ; This is called after config file parsing, so we know - ; the intended location of the ADV - ; -adv_init: - cmp byte [ADVDrive],-1 - jne adv_read - -%if IS_SYSLINUX || IS_EXTLINUX - cmp word [ADVSectors],2 ; Not present? - jb adv_verify - - mov eax,[Hidden] - mov edx,[Hidden+4] - add [ADVSec0],eax - adc [ADVSec0+4],edx - add [ADVSec1],eax - adc [ADVSec1+4],edx - mov al,[DriveNumber] - mov [ADVDrive],al - jmp adv_read -%endif - - ; - ; Initialize the ADV data structure in memory - ; -adv_verify: - cmp byte [ADVDrive],-1 ; No ADV configured, still? - je .reset ; Then unconditionally reset - - mov si,adv0 - call .check_adv - jz .ok ; Primary ADV okay - mov si,adv1 - call .check_adv - jz .adv1ok - - ; Neither ADV is usable; initialize to blank -.reset: - mov di,adv0 - mov eax,ADV_MAGIC1 - stosd - mov eax,ADV_MAGIC2 - stosd - xor eax,eax - mov cx,ADV_LEN/4 - rep stosd - mov eax,ADV_MAGIC3 - stosd - -.ok: - ret - - ; The primary ADV is bad, but the backup is OK -.adv1ok: - mov di,adv0 - mov cx,512/4 - rep movsd - ret - - - ; SI points to the putative ADV; unchanged by routine - ; ZF=1 on return if good -.check_adv: - push si - lodsd - cmp eax,ADV_MAGIC1 - jne .done ; ZF=0, i.e. bad - xor edx,edx - mov cx,ADV_LEN/4+1 ; Remaining dwords -.csum: - lodsd - add edx,eax - loop .csum - cmp edx,ADV_MAGIC2 - jne .done - lodsd - cmp eax,ADV_MAGIC3 -.done: - pop si - ret - -; -; adv_get: find an ADV string if present -; -; Input: DL = ADV ID -; Output: CX = byte count (zero on not found) -; SI = pointer to data -; DL = unchanged -; -; Assumes CS == DS. -; - -adv_get: - push ax - mov si,adv0.data - xor ax,ax ; Keep AH=0 at all times -.loop: - lodsb ; Read ID - cmp al,dl - je .found - and al,al - jz .end - lodsb ; Read length - add si,ax - cmp si,adv0.tail - jb .loop - jmp .end - -.found: - lodsb - mov cx,ax - add ax,si ; Make sure it fits - cmp ax,adv0.tail - jbe .ok -.end: - xor cx,cx -.ok: - pop ax - ret - -; -; adv_set: insert a string into the ADV in memory -; -; Input: DL = ADV ID -; FS:BX = input buffer -; CX = byte count (max = 255!) -; Output: CF=1 on error -; CX clobbered -; -; Assumes CS == DS == ES. -; -adv_set: - push ax - push si - push di - and ch,ch - jnz .overflow - - push cx - mov si,adv0.data - xor ax,ax -.loop: - lodsb - cmp al,dl - je .found - and al,al - jz .endz - lodsb - add si,ax - cmp si,adv0.tail - jb .loop - jmp .end - -.found: ; Found, need to delete old copy - lodsb - lea di,[si-2] - push di - add si,ax - mov cx,adv0.tail - sub cx,si - jb .nukeit - rep movsb ; Remove the old one - mov [di],ah ; Termination zero - pop si - jmp .loop -.nukeit: - pop si - jmp .end -.endz: - dec si -.end: - ; Now SI points to where we want to put our data - pop cx - mov di,si - jcxz .empty - add si,cx - cmp si,adv0.tail-2 - jae .overflow ; CF=0 - - mov si,bx - mov al,dl - stosb - mov al,cl - stosb - fs rep movsb - -.empty: - mov cx,adv0.tail - sub cx,di - xor ax,ax - rep stosb ; Zero-fill remainder - - clc -.done: - pop di - pop si - pop ax - ret -.overflow: - stc - jmp .done - -; -; adv_cleanup: checksum adv0 and copy to adv1 -; Assumes CS == DS == ES. -; -adv_cleanup: - pushad - mov si,adv0.data - mov cx,ADV_LEN/4 - xor edx,edx -.loop: - lodsd - add edx,eax - loop .loop - mov eax,ADV_MAGIC2 - sub eax,edx - lea di,[si+4] ; adv1 - mov si,adv0 - mov [si+4],eax ; Store checksum - mov cx,(ADV_LEN+12)/4 - rep movsd - popad - ret - -; -; adv_write: write the ADV to disk. -; -; Location is in memory variables. -; Assumes CS == DS == ES. -; -; Returns CF=1 if the ADV cannot be written. -; -adv_write: - push eax - mov eax,[ADVSec0] - or eax,[ADVSec0+4] - je .bad - mov eax,[ADVSec1] - or eax,[ADVSec1+4] - je .bad - cmp byte [ADVDrive],-1 - je .bad - - call adv_cleanup - mov ah,3 ; Write - call adv_read_write - - clc - pop eax - ret -.bad: ; No location for ADV set - stc - pop eax - ret - -; -; adv_read: read the ADV from disk -; -; Location is in memory variables. -; Assumes CS == DS == ES. -; -adv_read: - push ax - mov ah,2 ; Read - call adv_read_write - call adv_verify - pop ax - ret - -; -; adv_read_write: disk I/O for the ADV -; -; On input, AH=2 for read, AH=3 for write. -; Assumes CS == DS == ES. -; -adv_read_write: - mov [ADVOp],ah - pushad - - ; Check for EDD - mov bx,55AAh - mov ah,41h ; EDD existence query - mov dl,[ADVDrive] - int 13h - mov si,.cbios - jc .noedd - cmp bx,0AA55h - jne .noedd - test cl,1 - jz .noedd - mov si,.ebios -.noedd: - - mov eax,[ADVSec0] - mov edx,[ADVSec0+4] - mov bx,adv0 - call .doone - - mov eax,[ADVSec1] - mov edx,[ADVSec1+4] - mov bx,adv1 - call .doone - - popad - ret - -.doone: - push si - jmp si - -.ebios: - mov cx,adv_retries -.eb_retry: - ; Form DAPA on stack - push edx - push eax - push es - push bx - push word 1 ; Sector count - push word 16 ; DAPA size - mov si,sp - pushad - mov dl,[ADVDrive] - mov ax,4000h - or ah,[ADVOp] - push ds - push ss - pop ds - int 13h - pop ds - popad - lea sp,[si+16] ; Remove DAPA - jc .eb_error - pop si - ret -.eb_error: - loop .eb_retry - stc - pop si - ret - -.cbios: - push edx - push eax - push bp - - and edx,edx ; > 2 TiB not possible - jnz .cb_overflow - - mov dl,[ADVDrive] - and dl,dl - ; Floppies: can't trust INT 13h 08h, we better know - ; the geometry a priori, which means it better be our - ; boot device... - jns .noparm ; Floppy drive... urk - - mov ah,08h ; Get disk parameters - int 13h - jc .noparm - and ah,ah - jnz .noparm - shr dx,8 - inc dx - movzx edi,dx ; EDI = heads - and cx,3fh - movzx esi,cx ; ESI = sectors/track - jmp .parmok - -.noparm: - ; No CHS info... this better be our boot drive, then -%if IS_SYSLINUX || IS_EXTLINUX - cmp dl,[DriveNumber] - jne .cb_overflow ; Fatal error! - movzx esi,word [bsSecPerTrack] - movzx edi,word [bsHeads] -%else - ; Not a disk-based derivative... there is no hope - jmp .cb_overflow -%endif - -.parmok: - ; - ; Dividing by sectors to get (track,sector): we may have - ; up to 2^18 tracks, so we need to use 32-bit arithmetric. - ; - xor edx,edx - div esi - xor cx,cx - xchg cx,dx ; CX <- sector index (0-based) - ; EDX <- 0 - ; eax = track # - div edi ; Convert track to head/cyl - - ; Watch out for overflow, we might be writing! - cmp eax,1023 - ja .cb_overflow - - ; - ; Now we have AX = cyl, DX = head, CX = sector (0-based), - ; BP = sectors to transfer, SI = bsSecPerTrack, - ; ES:BX = data target - ; - - shl ah,6 ; Because IBM was STOOPID - ; and thought 8 bits were enough - ; then thought 10 bits were enough... - inc cx ; Sector numbers are 1-based, sigh - or cl,ah - mov ch,al - mov dh,dl - mov dl,[ADVDrive] - mov al,01h ; Transfer one sector - mov ah,[ADVOp] ; Operation - - mov bp,adv_retries -.cb_retry: - pushad - int 13h - popad - jc .cb_error - -.cb_done: - pop bp - pop eax - pop edx - pop si - ret - -.cb_error: - dec bp - jnz .cb_retry -.cb_overflow: - stc - jmp .cb_done - - section .data16 - alignz 8 -ADVSec0 dq 0 ; Not specified -ADVSec1 dq 0 ; Not specified -ADVDrive db -1 ; No ADV defined -ADVCHSInfo db -1 ; We have CHS info for this drive - - section .bss16 -ADVOp resb 1 - - section .text16 |