If grounding HOLD# at power-on is working for people so far, that's great to hear.
The SST datasheet implies that this is not the specified behavior, in fact my reading is that HOLD# is only sampled on SCK, and with CE# low. So perhaps it will be necessary to power up with HOLD# grounded by a pin grabber, then attach the SO8-clip-dongle with the LB/factory image and reset so the chipset reads from the dongle instead. If the chipset drives HOLD# directly, though, it gets a little messier; then it may be best to put a tristate-able buffer on the SO8-clip and overdrive the mobo's SPI flash signals for the 1-2 seconds needed to rewrite the whole thing, tristating as soon as the write is finished. That starts to require a pretty fast interface, driven over a cable, and now it's a lot messier than simply hotswapping a PLCC chip! Maybe the cost/complexity is enough of an incentive for people to improve their soldering skills (and observe good ESD practice). Soldering a bent-in DIP socket down and loading the flash on another DIP carrier is <$5 of parts, and you'll need the soldering iron for a more complex homebrewed programmer anyway. I myself like the idea of using a USB-capable Cypress PSOC micro (e.g. CY8C24894) to improve the programming cycle time, while extending the programmer cable length, but it helps that I already have the eval board for this one. Enjoy, Drew -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Segher Boessenkool Sent: Friday, November 24, 2006 7:23 AM To: Peter Stuge Cc: [email protected] Subject: Re: [LinuxBIOS] SPI flash focus > Unfortunately it requires some special characteristics in the board > schematic, to not risk destroying the chipset. > > "Warning: please do not try to use SF100 directly on the application > system if the scenario is not in the above two cases." > > ..from their manual. I agree with them, it could be dangerous to > drive the SPI chip while it's connected if you don't know exactly how > it is connected and that it really is safe on that particular board.. The only thing that is required is that they can safely pull the HOLD# pin to ground. Any sane design will have a pull-up resistor on that line (and most other SPI lines, for that matter). That said, there probably _are_ boards that do not have a sane design. Such a shame. [Oh, it obviously also doesn't work if the chipset or the motherboard design uses HOLD# for something else already. This isn't commonly done though]. Aaaaaanyway... It is really simple to build a device like this yourself for a few bucks. SPI flash has many nice characteristics. Segher -- linuxbios mailing list [email protected] http://www.openbios.org/mailman/listinfo/linuxbios -- linuxbios mailing list [email protected] http://www.openbios.org/mailman/listinfo/linuxbios
