RE: [Xen-staging] [xen-unstable] hvm rombios: Fix int15, func 0x86 (udelay).

RE: [Xen-staging] [xen-unstable] hvm rombios: Fix int15, func 0x86 (udelay).

[Petersson, Mats]

 

> -----Original Message-----
> From: xen-staging-bounces@lists.xensource.com 
> [mailto:xen-staging-bounces@lists.xensource.com] On Behalf Of 
> Xen staging patchbot-unstable
> Sent: 24 April 2007 12:16
> To: xen-staging@lists.xensource.com
> Subject: [Xen-staging] [xen-unstable] hvm rombios: Fix int15, 
> func 0x86 (udelay).
> 
> # HG changeset patch
> # User kfraser@localhost.localdomain
> # Date 1177413238 -3600
> # Node ID f71d167a6c6d7038fedc3d748db334f8ebba6467
> # Parent  a7bd11fd5b1b6f4a82135db09dfe654e8966fabe
> hvm rombios: Fix int15, func 0x86 (udelay).
> Was reading argument from wrong stack location with recent versions of
> bcc. Doing the access from [bp] rather than [sp] is safer as the
> former does not change all the time.
> Signed-off-by: Keir Fraser <keir@xensource.com>
> ---
>  tools/firmware/rombios/rombios.c |    7 ++-----
>  1 files changed, 2 insertions(+), 5 deletions(-)
> 
> diff -r a7bd11fd5b1b -r f71d167a6c6d tools/firmware/rombios/rombios.c
> --- a/tools/firmware/rombios/rombios.c	Tue Apr 24 
> 12:12:48 2007 +0100
> +++ b/tools/firmware/rombios/rombios.c	Tue Apr 24 
> 12:13:58 2007 +0100
> @@ -4157,15 +4157,12 @@ BX_DEBUG_INT15("int15 AX=%04x\n",regs.u.
>        DX = regs.u.r16.dx;
>  
>  ASM_START
> -      sti
> -
>        ;; Get the count in eax
> -      mov  bx, sp
>        SEG SS
> -        mov  ax, _int15_function.CX [bx]
> +        mov  ax, .int15_function32.CX [bp]

Minor nit: You don't need SEG_SS if you're using bp, as bp defaults to
SS segment. 
>        shl  eax, #16
>        SEG SS
> -        mov  ax, _int15_function.DX [bx]
> +        mov  ax, .int15_function32.DX [bp]
As above.

--
Mats
>  
>        ;; convert to numbers of 15usec ticks
>        mov ebx, #15
> 
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> 

Re: RE: [Xen-staging] [xen-unstable] hvm rombios: Fix int15, func 0x86 (udelay).

[Keir Fraser]

On 24/4/07 12:19, "Petersson, Mats" <Mats.Petersson@amd.com> wrote:

> Minor nit: You don't need SEG_SS if you're using bp, as bp defaults to
> SS segment. 
>>        shl  eax, #16
>>        SEG SS
>> -        mov  ax, _int15_function.DX [bx]
>> +        mov  ax, .int15_function32.DX [bp]
> As above.

Oh yes, I missed that simplification.

 -- Keir