Attachment 61350 Details for Bug 140119

[patch] make gfxboot detect byte-swapped cpio archives

gfxboot-cpio-swab.diff (text/plain), 1.72 KB, created by Colin Watson on 2005-12-19 11:01:01 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Colin Watson

Created: 2005-12-19 11:01:01 UTC

Size: 1.72 KB

patch

obsolete

>diff -Nur gfxboot-3.2.5/bincode.asm gfxboot-3.2.5.new/bincode.asm
>--- gfxboot-3.2.5/bincode.asm	2005-12-05 14:58:10.000000000 +0000
>+++ gfxboot-3.2.5.new/bincode.asm	2005-12-16 10:22:59.208000000 +0000
>@@ -441,6 +441,8 @@
> single_step		db 0
> show_debug_info		db 0
> 
>+fms_cpio_swab		db 0
>+
> hello			db 10, 'Initializing gfx code...', 10, 0
> msg_10			db '|ip %4x:  %8x.%x           |', 10, 0
> msg_11			db '|%2x: %8x.%2x', 0
>@@ -2698,10 +2700,17 @@
> 		jae fms_file_80
> 
> 		lin2segofs ebp,es,bx
>+		mov byte [fms_cpio_swab],0
> 		cmp word [es:bx],71c7h
>-		jnz fms_file_80
>-
>-		movzx ecx,word [es:bx+20]	; file name size
>+		jz fms_file_20			; normal cpio record
>+		cmp word [es:bx],0c771h		; maybe byte-swapped?
>+		jnz fms_file_80			; no cpio record
>+		mov byte [fms_cpio_swab],1
>+
>+fms_file_20:
>+		mov ax,[es:bx+20]		; file name size
>+		call cpio_swab
>+		movzx ecx,ax
> 		inc cx
> 		and cx,~1			; align
> 
>@@ -2710,8 +2719,13 @@
> 		cmp eax,ecx
> 		jb fms_file_80			; within header area
> 
>-		mov edx,[es:bx+22]		; data size
>-		rol edx,16			; strange word order
>+		mov ax,[es:bx+22]		; data size, MSW
>+		call cpio_swab
>+		mov dx,ax
>+		shl edx,16
>+		mov ax,[es:bx+24]		; data size, LSW
>+		call cpio_swab
>+		mov dx,ax
> 
> 		mov ebp,edx
> 		inc ebp
>@@ -2735,6 +2749,24 @@
> 
> ; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> ;
>+; byte-swap cpio data if appropriate
>+;
>+;  ax:		word to swap
>+;
>+; return:
>+;  ax:		swapped if [fms_cpio_swab], otherwise same as input
>+;
>+cpio_swab:
>+		cmp byte [fms_cpio_swab],0
>+		jz cpio_swab_90
>+		xchg ah,al
>+
>+cpio_swab_90:
>+		ret
>+
>+
>+; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>+;
> ; Load segment with 4GB selector.
> ;
> ;  byte [pm_seg_mask]	segment bit mask (bit 1-3: es, fs, gs)

Actions: View | Diff

Attachments on bug 140119: 61349 | 61350 | 61351