[flashrom] Support for HY29F002TC-90 rom

Michael Karcher flashrom at mkarcher.dialup.fu-berlin.de
Fri Jun 18 09:53:28 CEST 2010


Am Freitag, den 18.06.2010, 09:29 +0200 schrieb David Borg:
> I'm trying to add support for HY29F002T chips, however while testing
> the read function, I'm getting 2 differing sectors from the
> manufacturers bios which is burnt on the chip. The  following is the
> list of sectors on the device. The differing sectors are S4 and S5. S6
> matches the manufacturers bios too.
> 
> Sector	Size (Kbytes)  	Address Range
> S0		64			0x00000 - 0x0FFFF
> S1		64			0X10000 - 0X1FFFF
> S2		64			0X20000 - 0X2FFFF
> S3		32			0X30000 - 0X37FFF
> S4		8			0X38000 - 0X39FFF
> S5		8			0X3A000 - 0X3BFFF
> S6		16			0X3C000 - 0X3FFFF

S4 and S5 are called "parameter blocks", and you BIOS seems to use them
as intended. These blocks do not contain static BIOS code or data, but
system-dependent parameters, like the ESCD (extended system
configuration data). It is normal that parts of this are are reflashed
by the BIOS on bootup. It is also normal that these areas on a shipped
mainboards are not equal to the image on the web site of the
manufacturer (which typically are filled with 0xFF in that range). A
careful flash update would preserve these blocks over an BIOS update
(i.e. not reflash them). As the exact location of parameter areas is
highly dependant on the BIOS, flashrom has no implementation to check
what blocks are parameter areas on your system and reflashes everything,
which might cause loosing system serial numbers, UUIDs, Windows
preactivation code and event logs.

> This is the code I added in flashchips.c
[...]
> 		.probe_timing	= TIMING_FIXME,
Please look up the probe timing in the data sheet. If it doesn't mention
anything about delays while probing, use TIMING_ZERO.
Looks fine otherwise.

> Any ideas as to why that might be happening?
See above. The contents of S4 and S5 might be changing across reboot
which is *normal* and *expected*.

Regards,
  Michael Karcher





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