Re: [coreboot] Flash access on ASUS F2A85 variants

[Rudolf Marek]

Hi Stefan,

I just tried with v6402 which is open:

00:14.3 ISA bridge: Advanced Micro Devices [AMD] Hudson LPC Bridge (rev 11)
00: 22 10 0e 78 0f 00 20 02 11 00 01 06 00 00 80 00
10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 43 10 27 85
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
40: 04 00 00 00 d5 ff 03 ff 07 ff 00 00 00 00 00 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 30 02 00 00 00 00 0f 00 00 ff ff ff
70: 67 45 23 00 00 00 00 00 9c 00 00 00 05 0a 00 00
80: 08 00 03 a8 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 02 00 c1 fe 2f 01 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 e9 45 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 17 00 82 ff
d0: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

ruiktest ~ # hexdump -C a.bin
00000000  05 21 cc 6f 00 00 00 00  00 00 00 00 00 70 00 02  |.!.o.........p..|
00000010  06 20 04 04 06 04 9f 05  03 0b 0a 02 ff 88 00 3b  |. .............;|
00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|

The newer (locked) version from last email:

hexdump -C a.bin
00000000  05 21 4c 6f 00 00 00 00  00 06 00 00 00 70 00 02  |.!Lo.........p..|
00000010  06 20 04 04 06 04 9f 05  03 0b 0a 02 ff 88 00 3b  |. .............;|
00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
*

It looks that the the SPI CMD 06 is now restricted CMD for MAC and 
SPIhostaccesRomEn is clear.

I tried to boot with open version v6402 and then just clear the
SpiHostAccessRomEn without setting any other bits and I receive failure even for 
read:

./flashrom/flashrom -V -p internal  -r bios_open.bin

Found Winbond flash chip "W25Q64.V" (8192 kB, SPI).
This chip may contain one-time programmable memory. flashrom cannot read
and may never be able to write it, hence it may not be able to completely
clone the contents of this chip (see man page for details).
Reading flash... FIFO pointer corruption! Pointer is 0, wanted 3
Something else is accessing the flash chip and causes random corruption.
Please stop all applications and drivers and IPMI which access the flash chip.
Read operation failed!
FAILED.

Yes it looks like something is happening with flashrom / controller if 
SpiHostAccessRomEn is cleared.

Thanks
Rudolf