[LinuxBIOS] [PATCH] Fix i82810 to boot!

Uwe Hermann uwe at hermann-uwe.de
Tue Jun 19 10:36:12 CEST 2007

On Tue, Jun 19, 2007 at 02:29:20AM +0200, Stefan Reinauer wrote:
> * Uwe Hermann <uwe at hermann-uwe.de> [070619 02:24]:
> > General question: is there some reason to configure the PAM-controlled areas
> > to something other than "read/write" in any case? Do any modern OSes or
> > payloads which we might want to support _need_ the PAM regions to be
> > something other than read/write?
> Yes. ADLO.

OK, so we'll have to take care about that.

Which settings does ADLO require/expect?

Here's a list of the PAM registers and which regions they enable (on 440BX):

  PAM Reg   Attribute Bits       Memory Segment      Comments    Offset
PAM0[3:0]     Reserved                                            59h
PAM0[7:4] R  R     WE      RE 0F0000h ­ 0FFFFFh BIOS Area         59h
PAM1[3:0] R  R     WE      RE 0C0000h ­ 0C3FFFh ISA Add-on BIOS¹  5Ah
PAM1[7:4] R  R     WE      RE 0C4000h ­ 0C7FFFh ISA Add-on BIOS¹  5Ah
PAM2[3:0] R  R     WE      RE 0C8000h ­ 0CBFFFh ISA Add-on BIOS¹  5Bh
PAM2[7:4] R  R     WE      RE 0CC000h ­ 0CFFFFh ISA Add-on BIOS¹  5Bh
PAM3[3:0] R  R     WE      RE 0D0000h ­ 0D3FFFh ISA Add-on BIOS   5Ch
PAM3[7:4] R  R     WE      RE 0D4000h ­ 0D7FFFh ISA Add-on BIOS   5Ch
PAM4[3:0] R  R     WE      RE 0D8000h ­ 0DBFFFh ISA Add-on BIOS   5Dh
PAM4[7:4] R  R     WE      RE 0DC000h ­ 0DFFFFh ISA Add-on BIOS   5Dh
PAM5[3:0] R  R     WE      RE 0E0000h ­ 0E3FFFh BIOS Extension    5Eh
PAM5[7:4] R  R     WE      RE 0E4000h ­ 0E7FFFh BIOS Extension    5Eh
PAM6[3:0] R  R     WE      RE 0E8000h ­ 0EBFFFh BIOS Extension    5Fh
PAM6[7:4] R  R     WE      RE 0EC000h ­ 0EFFFFh BIOS Extension    5Fh

Do we have or want a general LinuxBIOS-wide policy as to how to set the
PAM registers? Or is this chipset-/mainboard-specific?

IMO we should make sure that ADLO can be used on _all_ boards. It's no
problem to have a config option and a reasonable default, but there
should definately be a possibility for the "end user" to easily use ADLO
without having to touch the source code.

http://www.hermann-uwe.de  | http://www.holsham-traders.de
http://www.crazy-hacks.org | http://www.unmaintained-free-software.org
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://www.coreboot.org/pipermail/coreboot/attachments/20070619/2161c6e9/attachment.sig>

More information about the coreboot mailing list