[Qemu-devel] Re: [Bochs-developers] [PATCH v2 4/6] Execute rombios32 code fromromaddress 0xe0000.

[Gleb Natapov]

On Mon, Nov 10, 2008 at 08:25:07PM +0100, Sebastian Herbszt wrote:
> Gleb Natapov wrote:
>> On Sat, Nov 08, 2008 at 12:20:56AM +0100, Sebastian Herbszt wrote:
>>>> diff --git a/bios/rombios32start.S b/bios/rombios32start.S
>>>> index 601e2b0..1900261 100644
>>>> --- a/bios/rombios32start.S
>>>> +++ b/bios/rombios32start.S
>>>> @@ -32,10 +32,17 @@ _start:
>>>>   /* clear bss section */
>>>>   xor %eax, %eax
>>>>   mov $__bss_start, %edi
>>>> -  mov $_end, %ecx
>>>> +  mov $__bss_end, %ecx
>>>>   sub %edi, %ecx
>>>>   rep stosb
>>>
>>> We do overwrite data at 0x700 here. Is this acceptable for S3 resume?
>>>
>> First page is reserved for BIOS use.
>
> I might have missed something, but Ralf Brown's MEMORY MAP
> Release 61 says "MEM 0070h:0000h - DOS 2+ IO.SYS LOAD ADDRESS".
>
> Which specification do you refer to?
>
DOS does not support S3 :). Linux reserve first page for BIOS use (as
can be seed in the code). As far as I know Windows doesn't touch even
more of low memory.

--
                        Gleb.