[syslinux] [PATCH] memdisk: "safe hook" and mBFT

[H. Peter Anvin]

On 12/06/2009 07:46 PM, Shao Miller wrote:
> H. Peter Anvin wrote:
>>
>> On 12/06/2009 05:15 PM, Shao Miller wrote:
>> > @@ -117,13 +117,33 @@
>> >         section .text
>> >         ; These pointers are used by the installer and
>> >         ; must be first in the binary
>> > -Pointers:    dw Int13Start
>> > +Pointers:    dw SafeHook
>>
>> This pointer is part of the documentation; we really shouldn't change
>> it.  If we need another pointer we can just add it -- it is only two
>> bytes.
>>
> 
> In this particular instance, the "safe hook standard" (if you can call
> it that) wants the structure to reside at exactly the hook's entry
> point.  I simply did this because we install based on this field.  If
> you're suggesting an additional change to setup.c, I can do that.
> 
>     /* Install the interrupt handlers */
> 
>    printf("old: int13 = %08x  int15 = %08x  int1e = %08x\n",
>           rdz_32(BIOS_INT13), rdz_32(BIOS_INT15), rdz_32(BIOS_INT1E));
> 
>    wrz_32(BIOS_INT13, driverptr + hptr->int13_offs);
>    wrz_32(BIOS_INT15, driverptr + hptr->int15_offs);
>    if (pptr->dpt_ptr)
>        wrz_32(BIOS_INT1E, driverptr + pptr->dpt_ptr);
> 

Actually, what I think we should do then is to leave the pointers
pointing to Int13Start and just use an offset to the safe hook structure.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.