> -----Original Message----- > From: Jordan Crouse [mailto:[EMAIL PROTECTED] > Sent: Wednesday, July 16, 2008 1:55 PM > To: Myles Watson > Cc: Kevin O'Connor; Carl-Daniel Hailfinger; Coreboot > Subject: Re: SeaBIOS debug output > > On 16/07/08 12:43 -0600, Myles Watson wrote: > > On Fri, Jul 11, 2008 at 12:51 PM, Kevin O'Connor <[EMAIL PROTECTED]> > wrote: > > > On Fri, Jul 11, 2008 at 07:58:35PM +0200, Carl-Daniel Hailfinger > wrote: > > >> Can seabios somehow complement x86emu as a way to let certain > > >> problematic VBIOS images run? > > > > > > If you mean run seabios under x86emu - I'm not sure. Seabios > > > currently does its initialization in 32bit mode which x86emu may not > > > like. > > > > > > If you mean using seabios to implement the option rom scan - then yes, > > > I think this is what Stefan suggested and Zhang Rui is working on. If > > > I understand correctly, they want to load the seabios blob into ram, > > > have seabios do its init, run the option roms, and then jump back to > > > coreboot for the rest of the boot. Presumably, coreboot would also > > > use seabios to boot the machine if the user wanted that. > > > > > > The thing to be careful of here is making sure coreboot and seabios > > > don't stomp on each other. This may not be such a big deal - seabios > > > doesn't currently write to any ram above 1MiB - if coreboot didn't > > > write to any ram below 1MiB after launching seabios then maybe it > > > would work. > > > > I for one don't understand what needs to be done in coreboot after the > > option ROM scans. It seems like it would help us discuss the possible > > solutions if we could enumerate that. > > > > I don't think the Coreboot->SeaBIOS->Coreboot->Payload route means > > that SeaBIOS has to return to Coreboot. It seems like Coreboot can > > load whatever should come after SeaBIOS into RAM and have SeaBIOS jump > > there. > > This seems like semantics to me - the jmp will be to an arbitrary > address - it doesn't really matter if it goes back to coreboot or > if it goes to the payload. If it jumped to the payload, SeaBIOS > will have to be told _where_ to jump anyway, since the payload can > live anywhere. All we really need to do is set up an interface to pass a > address to SeaBIOS, and then its up to coreboot to figure out what > they want to do after SeaBIOS is done.
My point was that there didn't need to be a preservation of stack state, global variables, etc. When I think of a return from a function call, it seems a lot more complex than jumping to a separate payload. I thought that was the problem. Thanks, Myles > Jordan > > -- > Jordan Crouse > Systems Software Development Engineer > Advanced Micro Devices, Inc. -- coreboot mailing list [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
