[coreboot] YABEL and images in LAR files

Myles Watson mylesgw at gmail.com
Fri Dec 19 18:05:37 CET 2008

> -----Original Message-----
> From: Jordan Crouse [mailto:jordan at cosmicpenguin.net]
> Sent: Friday, December 19, 2008 9:48 AM
> To: Myles Watson
> Cc: Pattrick Hueper; Coreboot
> Subject: Re: [coreboot] YABEL and images in LAR files
> Myles Watson wrote:
> > Patty,
> >
> > For some devices, Coreboot has the ROM image in a section of the ROM.
> It
> > copies that image to memory and passes a pointer to run_bios.  Actually,
> > right now Coreboot copies the ROMs to RAM for devices too.  YABEL works
> when
> > the ROM is accessible from the device (by ignoring the fact that
> Coreboot
> > already copied it), but not in the case that Coreboot expects it to be
> run
> > from RAM.  Do you have any thoughts on how to handle this case?
> >
> > Thanks,
> > Myles
> We don't _have_ to copy it to RAM, it just never occurred to us that it
> shouldn't be.  However, if we leave it on the ROM, don't we hit the same
> issue with the shadowed memory that we did with the shared functions a

I think it needs to be copied to RAM.  I was just wondering who should do
that copy.  YABEL doesn't have a way of knowing where to find the ROM for
onboard devices that have their ROM images imbedded in a LAR file.  That
information isn't in the ROM BAR.  That's why we pass the address to
bios_run.  Right now YABEL just ignores that address.

I was just trying to think of the cleanest way to handle the following
1. The device is an add-in card with its own ROM.
2. The device is onboard and coreboot has the ROM image.
3. The device is an add-in card and coreboot wants to initialize it with a
different ROM.

I know 3 is unusual, but it might be useful sometimes.


More information about the coreboot mailing list