On Tue, Aug 12, 2014 at 3:07 PM, Stefan Tauner <[email protected]> wrote: > On Tue, 12 Aug 2014 12:15:53 -0400 (EDT) > [email protected] wrote: > >> 0x54: 0x000f0000 FREG0: Warning: Flash Descriptor region >> (0x00000000-0x0000ffff) is read-only. >> 0x58: 0x07ff0200 FREG1: BIOS region (0x00200000-0x007fffff) is read-write. > > Hello Wen, > > it seems like this bogus kind of descriptor layout becomes popular. Let > me explain in case you don't understand: The descriptor region in the > first 4kB of the flash chip - similar to a partition table - defines > (among other things) which parts of the flash chip are used for what > components. Usually all addresses of the flas chip are covered by this > but sometimes vendor forget to do this properly - or do have no use for > it. > > The problem (for flashrom) is that the Intel SPI controllers forbid > accesses to addresses that are not covered by the descriptor regions - > like 0x00010000 to 0x001FFFFF in this case, which is almost a quarter > of the flash chip - but flashrom tries to read the whole chip > nevertheless (for good reasons). > > So flashrom works more or less as expected on that board as far as you > have tested it. That result is probably not very useful to you, but > fine with me for now... :) > > If you want to be able to write to the BIOS region, you > will also need my layout patches (they are also on github), and also > set the read_all_first variable in doit() in flashrom.c to 0. > I'd welcome such further tests of course but please be prepared for > recovery if need be. > > I have included Marc from Sage because I guess he may be able to tell > us about the reason for this.
I recommend that you use and external programmer to re-write the descriptor as you need for development. The coreboot ifdtool is helpful for this. (someone want to post a how-to on the wiki?) Marc > -- > Kind regards/Mit freundlichen Grüßen, Stefan Tauner _______________________________________________ flashrom mailing list [email protected] http://www.flashrom.org/mailman/listinfo/flashrom
