On 22.12.2009 18:41, Luc Verhaegen wrote: > On Tue, Dec 22, 2009 at 02:25:41PM +0100, Carl-Daniel Hailfinger wrote: > >> On 22.12.2009 13:52, Luc Verhaegen wrote: >> >>> On Tue, Dec 22, 2009 at 03:48:38AM +0100, Carl-Daniel Hailfinger wrote: >>> >>> >>>> On 16.12.2009 12:14, Luc Verhaegen wrote: >>>> >>>> >>>>> Chipset/Board: vt8237: Set All mem cycles to LPC in chipset enable. >>>>> >>>>> >>>>> >>>> I don't have the datasheet, so I can't cross-check. I'm very interested >>>> why this would be needed, though. If mem cycles don't go to LPC and we >>>> have flash on LPC, the board won't boot anyway. If we force mem cycles >>>> to LPC although we have parallel ROM, this will break. Does VT8237R >>>> support parallel ROMs? >>>> >>>> >>> We need this, otherwise we wouldn't be changing this many board enables >>> now. >>> >>> >> Ah hm. I thought most board enables were created by imitating the >> behaviour of the in-memory board enable code, not by checking for the >> necessity of each step in there. >> If there are VT8237R straps which select the ROM type, we should check >> them and warn very loudly if a board strapped to parallel gets all >> memory accesses redirected to LPC. That will make sure users know WTF >> went wrong (if something went wrong). >> >> >> >>> About parallel roms, no idea, but if we apply this patch, we should soon >>> find out. >>> >>> >>> >>>> Side note: Should we read the ROMCS# strap on VT8235 to check whether >>>> the ROM is LPC or Parallel? Does this strap exist for other VT823x as well? >>>> >>>> >> The strap reading is IMHO very desirable because it can reduce the >> number of probed chips roughly by half. >> > > The bit we are setting is the following: > > ROM Memory Cycles Go To LPC > 0 Disable (all memory cycles go to LPC). default. > 1 Enable (only ROM memory cycles go to LPC). > > What we do is set this bit to 0. > > This bit is present in 8235 too, but there it seems to be not necessary. > > It seems like a bug in vt8237R, and in 8237R only, as we only need to > set it there. >
Thanks for the explanation. A slightly modified patch was committed in r815. Regards, Carl-Daniel -- Developer quote of the month: "We are juggling too many chainsaws and flaming arrows and tigers." _______________________________________________ flashrom mailing list [email protected] http://www.flashrom.org/mailman/listinfo/flashrom
