[flashrom] AMIC A25L40P{B,U}

[Daniel Lenski]

Hi Rudolf,

On Mon, 2010-07-12 at 21:52 +0200, Rudolf Marek wrote:
> > What happens if you try to selectively write or erase only the bottom 4
> > KB of each chip?
> 
> Well I tried to write there 512KB of zeros using -c A25L40PT with PT chip
> then erase with -E -c A25L40PT
> 
> This works fine. Same with PU chip with -c A25L40PU. However if there is some
> combination of non-agreeing chips/params I got hard lockup of whole computer.

Okay, so write/erase works fine with the setting that matches the chip
in hand?

> 
> 
> With PU chip, written all 0's with right switch and then erasing PT param:
> 
> ruiktest:~/flashrom#  ./flashrom -VE -c A25L40PT
> Erasing flash chip... Looking at blockwise erase function 0... trying...
> 0x000000-0x00ffff, ERASE FAILED at 0x00001000! Expected=0xff, Read=0x00, failed
> byte count from 0x00000000-0x0000ffff: 0xf000
> ERASE FAILED!
> 
> Looking at blockwise erase function 1... trying... 0x000000-0x07ffff,
> 

This is really useful to know!  The blockwise erase function fails at
the 4 K (0x1000) mark.  The flashrom program expects to erase a 64 K
segment (0x10000) because it thinks it is talking to a PT chip, but it
only gets 4 K erased, because the chip is really a PU.  That makes
sense!

What about the reverse case?  What if you put in the PT chip and tell
flashrom that it's a PU?  flashrom -VE -c A25L40PU
In this case, it should fail when it tries to erase the /upper/ region
of the memory, because flashrom is expecting to erase a 64 K chunk, but
only getting 4 K since it is really a top boot block chip.

If that's really what happens... then I am convinced once and for all
that the PT and PU really are distinct chips!

> <hang>
> 
> It hangs pretty solid, keyboard non-responsive.

I don't understand why it hangs...  I guess this is an issue with your
chipset?

Dan