Flashing coreboot and Intel Flash Descriptor Erase Issue

[Balaji Sivakumar]

Hello Everyone,

We are using SPI flash(Macronix) to program the BIOS. And we use an
external programmer to flash the BIOS (coreboot including FD+ME) into SPI
Flash (16384 kB, SPI), it works fine and boots well. The board is
functional and we have successfully booted a kernel on it.

Am working on adding a feature to upgrading the BIOS (complete
IFD+ME+Coreboot) using intel-spi driver at the OS level. Able to
successfully take the backup full 16MB spi nor flash data which
includes IFD+ME+BIOS using flashrom Internal Programmer option and it is
identified as Opaque flash chip and using dd command as well.

But we are seeing the erase fail through both flashrom and flash_erase
utility. I believe it fails to erase at the flash descriptor location.

As far as Read/Write access to the SPI regions, I have enabled the Host CPU
BIOS write access and ME Master Access as 0xFFFF through Intel FIT Tool but
still not able to erase it and it fails.

Is there anything that could be preventing to enable read/write access to
the Intel flash descriptor or any SOC SPI controller protection to access
the Flash descriptor?

Any pointers would be appreciated.

Thanks
Balaji