Re: Extboot Option ROM rewritten in C - v2

[Anthony Liguori <aliguori@us.ibm.com>]

Anthony Liguori wrote:
> A couple general comments.
>
> I'd feel a lot more comfortable with the int13 handler returning an 
> int and the asm stub code uses that result to determine how to set 
> CF.  You set CF deep within the function stack and there's no 
> guarantee that GCC isn't going to stomp on it.

Ignore that bit, I missed that you were only setting it within the regs 
structure.

Regards,

Anthony Liguori

> I also don't think we want to raise int18 when we get a command we 
> don't understand.  We should just not change any of the register 
> state.  There are a number of extended commands that look for a magic 
> value to determine whether the command exists or not.
>
> Regards,
>
> Anthony Liguori
>
> Nguyen Anh Quynh wrote:
>> Hi Anthony,
>>
>> I found a bug in the last code: send_command() failed to copy back the
>> result into extboot_cmd structure. This patch fixes it.
>>
>> I succesfully tested this version with guest Win2K (fully updated,
>> scsi boot) and Linux 2.6.25-rc8 (virtio).
>>
>> Let me know if you can boot Windows with this version.
>>
>> Thanks,
>> Quynh
>> ---
>> This code is an attempt to rewrite the current extboot option rom in
>> C. The new code now minimize the assembly code, so that the assembly
>> code is very small and simple: boot.S's only job is to interface with
>> C code, which does all the dirty job. "signrom" is modified to adapt
>> with the new result binary image.
>>
>> The result option rom has the same size as the original one: 1.5KB,
>> while the actual code size is around the same: 1.2KB (gcc can optimize
>> really well)
>>
>> To install this option rom, do the following steps as root:
>>
>> make
>> make save         <--- backup the original option rom to
>> /usr/share/qemu/extboot.bin.org
>> make install       <--- overwrite the new option rom to
>> /usr/share/qemu/extboot.bin
>>   
>
>


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