[coreboot] How to test
corey.osgood at gmail.com
Wed Dec 17 21:50:30 CET 2008
On Wed, Dec 17, 2008 at 2:16 PM, Vikram Hegde <vikhegde1 at yahoo.com> wrote:
> I am a newbie interested in contributing to coreboot. One question I have
> is testing.
> How do most people test new bits. Do they actually flash the BIOS on their
> motherboards. Doesn't that cause issues because as I understand these PROMs
> only support a limited number of flashes before they go bad ? Or do folks
> use some sort of emulator and/or spare chips to keep testing.
You definitely want spare chips, if coreboot fails for any reason, you need
to have your stock BIOS accessable, all the stock BIOS's failsafes are
overwritten by coreboot. Todays flash chips can survive thousands of
erase/write cycles, and most chips cost <$5USD. I have a now-discontinued
product called the BIOS Savior RD-1 that I'm currently using, it has a
second flash chip and a socket for the original chip built into it, so all
you do is flip a switch to change from one chip to the other. If you can
find one that works with your system, they're an awesome tool. My testing
cycle is basically:
Boot stock bios (base Debian testing install, boots in ~30 seconds)
Throw switch or change chip
Flash spare chip w/coreboot, transferred via USB flash drive
Fire up minicom on my other computer, to monitor coreboot progress
Press power button, see what happens
Throw switch or change chip back, repeat.
I also hacked flashrom so that it can't detect my stock BIOS chip, only the
spare chip I use for testing coreboot, so I can't accidentally overwrite the
> Also any inexpensive standalone bios chip programmers on the market ?
Yes, but most are also very slow. My willem (~$50USD) takes around 7min to
program a 512k chip through a parallel port, and it only works under 32-bit
windows, or some have reported success with linux and wine. I've only used
it maybe 3 or 4 times, to reprogram stock BIOS's before I smartened up and
hacked flashrom, and also programmed another spare chip with the stock BIOS
and stuffed it in an envelope in a file cabinet. Also see the discussion on
the list about the Paraflasher, a similar in-development LPC flasher that
will work under linux when it's done, but again it will probably be fairly
Hope this helps,
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