[coreboot] flashrom fails to write/erase on VIA VT8237

[Peter Stuge]

Hello Vinod,

vinuxesgmail wrote:
> # flashrom -E -f
> Calibrating delay loop... OK.
> No coreboot table found.
> Found chipset "VIA VT8237", enabling flash write... OK.
> Found chip "SST SST49LF004A/B" (512 KB) at physical address 0xfff80000.
> *Erasing flash chip... ERASE FAILED!
> FAILED!
> ERROR at 0x00000000: Expected=0xff, Read=0x49

..

> To describe my board, here's the output of lspci:
> {------------------
> 00:00.0 Host bridge: VIA Technologies, Inc. CN700/VN800/P4M800CE/Pro Host Bridge
> 00:00.1 Host bridge: VIA Technologies, Inc. CN700/VN800/P4M800CE/Pro Host Bridge
> 00:00.2 Host bridge: VIA Technologies, Inc. CN700/VN800/P4M800CE/Pro Host Bridge
> 00:00.3 Host bridge: VIA Technologies, Inc. PT890 Host Bridge
> 00:00.4 Host bridge: VIA Technologies, Inc. CN700/VN800/P4M800CE/Pro Host Bridge
> 00:00.7 Host bridge: VIA Technologies, Inc. CN700/VN800/P4M800CE/Pro Host Bridge
> 00:01.0 PCI bridge: VIA Technologies, Inc. VT8237/VX700 PCI Bridge
> 00:09.0 Ethernet controller: Intel Corporation 8255xER/82551IT Fast Ethernet Controller (rev 10)
> 00:0a.0 Ethernet controller: Intel Corporation 8255xER/82551IT Fast Ethernet Controller (rev 10)
> 00:0c.0 Ethernet controller: Intel Corporation 8255xER/82551IT Fast Ethernet Controller (rev 10)
> 00:0d.0 Ethernet controller: Intel Corporation 8255xER/82551IT Fast Ethernet Controller (rev 10)
> 00:0f.0 IDE interface: VIA Technologies, Inc. VIA VT6420 SATA RAID Controller (rev 80)
> 00:0f.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
> 00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
> 00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
> 00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
> 00:10.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
> 00:11.0 ISA bridge: VIA Technologies, Inc. VT8237 ISA bridge [KT600/K8T800/K8T890 South]
> 01:00.0 VGA compatible controller: VIA Technologies, Inc. CN700/P4M800 Pro/P4M800 CE/VN800 [S3 UniChrome Pro] (rev 01)

> Am i doing it wrong? Please guide me.

No, you're doing everything right, but flashrom seems to need special
support to be able to write to the flash chip on this mainboard. A
so-called board enable function needs to be written, which should set
a few bits correctly in some register in some chip.

Please answer these two questions:

1. Which vendor and board is this? Is it VIA NAB-7400?
2. Please find out where pin 7 WP# and 8 TBL# on the flash chip are
   connected. To which pin on which chip?

I think it should be easy to add full support for your board when we
know this. One possible problem is that on the NAB-7400 there are
only BGA chips which can not really be measured easily by hand.


//Peter