Question about how CoreBoot handles Option ROM

[Jeffrey C. Jacobs]

I was wondering if someone could point me to the right direction in terms of
where in CoreBoot is are the various system Option ROMs copied.  As I
understand it, Option ROMs are generally found by probing the PCI bus and
copied into RAM so that they can be handled by INT13 requests.  So, I'd like
to know what part of the code handles that and also how the memory map of
those copied addresses are laid out.
Thanks in advance,

Jeffrey

[ron minnich]

On Wed, Aug 19, 2009 at 7:44 AM, Jeffrey C. Jacobs wrote:
> I was wondering if someone could point me to the right direction in terms of
> where in CoreBoot is are the various system Option ROMs copied.  As I
> understand it, Option ROMs are generally found by probing the PCI bus and
> copied into RAM so that they can be handled by INT13 requests.  So, I'd like
> to know what part of the code handles that and also how the memory map of
> those copied addresses are laid out.

nowadays, most of the work  is  done in cbfs.

ron

[Myles Watson]

On Wed, Aug 19, 2009 at 8:44 AM, Jeffrey C. Jacobs wrote:
> I was wondering if someone could point me to the right direction in terms of
> where in CoreBoot is are the various system Option ROMs copied.

There are two answers to this question depending on how you want it to happen.
1. Coreboot and vm86, yabel, or x86emu
look in src/devices/pci_rom.c and src/devices/pci_device.c

It's controlled by CONFIG_PCI_ROM_RUN, CONFIG_VGA_ROM_RUN, CONFIG_CONSOLE_VGA,
CONFIG_PCI_OPTION_ROM_RUN_YABEL, CONFIG_PCI_OPTION_ROM_RUN_REALMODE...

I'm not sure about multiple ROMs at once.

2. SeaBIOS
Put the ROMs in CBFS with the correct device ID and vendor ID, and
disable Coreboot's ROM running.  SeaBIOS will handle them all.

Thanks,
Myles

[ron minnich]

On Wed, Aug 19, 2009 at 8:23 AM, Myles Watson wrote:
> SeaBIOS
>
> Put the ROMs in CBFS with the correct device ID and vendor ID, and
> disable Coreboot's ROM running.  SeaBIOS will handle them all.

In the long term, if you want to work with the world's option ROMs,
this is almost always the right answer.

ron