Re: [Qemu-devel] [PATCH 0/2] extboot reloaded.

[Anthony Liguori <anthony@codemonkey.ws>]

Gerd Hoffmann wrote:
> On 11/16/09 20:24, Anthony Liguori wrote:
>> If we were going to introduce a light weight block protocol like this,
>> I'd rather it be implemented in SeaBIOS as a block driver.
>
> Ok.  That would mean to replace the option rom with a seabios patch. 
> The qemu code will be unmodified though (except for the rom loading).

Yup.

>> and requires no special options on the
>> command line.
>>
>> It would require a mechanism to do enumeration and identification 
>> though.
>
> Huh?  Do you want export *all* block devices via extboot?  Will IDE 
> drives show up twice then?

No, because SeaBIOS already has an ATA driver so we wouldn't want to 
expose IDE on the extboot bus.

> I would export only one and export it only on explicit user request, 
> so it can be used for cases where seabios has no native support ...

If we expose all of the disks, then the user can choose which one they 
want to boot from without having to shut down qemu and modify the 
command line.

It's not obvious to me how we could control the position in the IPL 
table of each disk though.  I guess we could have a priority parameter 
that was part of the disk enumeration that controlled how each device 
was added in the table.  Do you have any thoughts Kevin?

Regards,

Anthony Liguori