diff options
| -rw-r--r-- | core/adv.inc | 64 |
1 files changed, 39 insertions, 25 deletions
diff --git a/core/adv.inc b/core/adv.inc index c5e8270c..1fe5aca2 100644 --- a/core/adv.inc +++ b/core/adv.inc @@ -341,25 +341,6 @@ adv_read_write: mov [ADVOp],ah pushad - 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. Handle that later. - ; jns .floppy ; Floppy drive... urk - - mov ah,08h ; Get disk parameters - int 13h - jc .noparm - and ah,ah - jnz .noparm - shr dx,8 - inc dx - mov [ADVHeads],dx - and cx,3fh - mov [ADVSecPerTrack],cx - -.noparm: ; Check for EDD mov bx,55AAh mov ah,41h ; EDD existence query @@ -367,6 +348,10 @@ adv_read_write: int 13h mov si,.cbios jc .noedd + cmp bx,0AA55h + jne .noedd + test cl,1 + jz .noedd mov si,.ebios .noedd: @@ -422,8 +407,38 @@ adv_read_write: push eax push bp - movzx esi,word [ADVSecPerTrack] - movzx edi,word [ADVHeads] + 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. @@ -453,7 +468,7 @@ adv_read_write: mov ch,al mov dh,dl mov dl,[ADVDrive] - xchg ax,bp ; Sector to transfer count + mov al,01h ; Transfer one sector mov ah,[ADVOp] ; Operation mov bp,adv_retries @@ -467,6 +482,7 @@ adv_read_write: pop bp pop eax pop edx + pop si ret .cb_error: @@ -481,9 +497,7 @@ adv_read_write: ADVSec0 dd 0 ; Not specified ADVSec1 dd 0 ; Not specified ADVDrive db -1 ; No ADV defined +ADVCHSInfo db -1 ; We have CHS info for this drive section .bss - alignb 4 -ADVSecPerTrack resw 1 -ADVHeads resw 1 ADVOp resb 1 |