[LinuxBIOS] Intel Southbridge ROM Protection mechanism

Stefan Reinauer stepan at coresystems.de
Fri Apr 20 01:37:54 CEST 2007

* Darmawan Salihun <darmawan.salihun at gmail.com> [070419 19:22]:
> the matter, does Intel ICH5 southbridge  (or other newer Inte southbridge)
> still protects (probably mirrors) the last 8KB block (bootblock) in the BIOS
> chip even when the protection bits in Block Locking Registers (BLRs) has been
> disabled?
>     I experienced weird results between several flashing attempts using
> flashrom in Linux. SOme succeeded, some retain the original values. Anyone has
> an explanation on the issue?

Some flash chips support "write protecting" their boot block (and/or other
blocks). I think the data sheets have more details on this.

What flash chip are you using?

Usually if the south bridge or a GPIO does the protection, you'd be able
to write all or nothing. AFAIK

coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br.
      Tel.: +49 761 7668825 • Fax: +49 761 7664613
Email: info at coresystems.dehttp://www.coresystems.de/

More information about the coreboot mailing list