[SerialICE] an idea

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Thu Nov 26 16:16:16 CET 2009


On 26.11.2009 05:55, ron minnich wrote:
> Then, I could on my 1580s do test bios images, secure in knowing that
> I can always fall back to serialice and recover. Possibly we could
> have serialice be an "external programmer" for flashrom!
>   

As a flashrom developer, here's my take on the issue.

There are two ways to do this:
1. Link flashrom with libpayload and have it stored in the ROM. Needs
working RAM to be useful.
2. Add serialice support to flashrom via an external programmer driver.
Will not work reliably for parallel and LPC flash due to timing
constraints: we have a few timeouts in the order of 50 µs (microseconds)
during programming and I doubt we can reach a sustained data rate of 5
bytes (1 command, 3 addr, 1 data) per 50 µs (100 kByte/s, 800 kbit/s)
over serial.

Variant 1 has no problems with timing and can be solved with libflashrom
(TBD) and some new interface.
Variant 2 has no problems on SPI hosts and can be implemented right now.

Both variants require partial erase/write which needs acks for pending
flashrom patches.

Regards,
Carl-Daniel

-- 
Developer quote of the month: 
"We are juggling too many chainsaws and flaming arrows and tigers."




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