[flashrom] more testing DELL Dimension 4100

[Bertho Grandpied]

Hi again, List !

This week end, got spare time to investigate further with the Dell. 
Visual inspection (subsequently confirmed by software probing) has shewn the DELL/Intel Mobo's FWH is indeed the Intel part 82802AB as initially supposed - rather than being an SST substitute or otherwise (a possibility suggested by Stefan Tauner). 

In summary, relevant chips found on this board were :
- Intel 82801BA (ICH2)
- Intel 82802AB (FWH)
- SMSC LPC47M102S-MC (superIO)

The question then arises: why does Flashrom NOT detect/report the 82802 ?

It's been noted and verified that our BIOS sets the locking bit in the 82801 that would cause a BIOS trap (SMI) on attempted /write/ accesses to the firmware, and suggested that one or more confidential GPO should have to be flipped in order to authorise such access....
__________________________________________________________________

Proceeding anyway because user forced us to.
Found chipset "Intel ICH2" with PCI ID 8086:2440. Enabling flash write... 
BIOS_CNTL = 0x02: BIOS Lock Enable: enabled, BIOS Write Enable: disabled
WARNING: Setting Bios Control at 0x4e from 0x02 to 0x03 on ICH2 failed.
New value is 0x02.
FAILED!
__________________________________________________________________


BUT that mechanism doesn't seem to be able to HIDE the 82802 from Flashrom ! Or am I mistaken ? Here are the relevant probes listed :

__________________________________________________________________
The following protocols are supported: FWH.
Probing .....
Probing for Intel 82802AB, 512 kB: probe_82802ab: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for Intel 82802AC, 1024 kB: probe_82802ab: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
.... ....
No EEPROM/flash device found.
Note: flashrom can never write if the flash chip isn't found automatically.
Restoring PCI config space for 00:1f:0 reg 0x4e
_________________________________________________________________

Please explain what circumstances can cause the above result yet an I82802AB is positively present. 

BTW, I flipped GPO bits (from the 82801) without resulting any change whatsoever in flashrom's reports. I could try the same with GPOs from the SuperIO instead, but first I think I'll be waiting for more advice, ideas and... encouragement from Stefan and the List. 

Regards

-- 
Czerno