I have added Denverton support in the flashrom and I found that SMM Protection is enabled from the logs.

I have tried to disable it using setcpi utility and it remains the same value. Also the flashrom utility also tries but it remains the same.

Warning: BIOS region SMM protection is enabled!
Warning: Setting Bios Control at 0xdc from 0xab to 0x89 failed.

Also FLOCKDN=1 is set as 1 as well.

I can clearly tell the BIOS region is read and writable but Protected registers are read only that's also the reason I am not able to write the BIOS region.

What are the options/methods to unlock / disable the Bios Write enable(BIOS_CNTL) or to access the HSFS registers to set the FLOCKDN bit to 0.

Any pointers would be appreciated!

On Sun, Oct 18, 2020 at 4:20 PM Balaji Sivakumar <shivbalaji1985@gmail.com> wrote:

There is some documentation in the tree to help explain the "opaque flash chip": https://review.coreboot.org/cgit/flashrom.git/tree/Documentation/mysteries_intel.txt#n8

-        Thank you David for the details, I will go through this.

You will also need to enable host CPU write access to other regions you with to be writeable. From your earlier e-mail it appears that you've already done this for the ME region, however you'll need to do it for IFD and other regions you wish to update. Be advised, however, that *not* locking certain regions may cause the ME to behave differently.

-        I have enabled Read write access to the Host CPU Bios, Intel ME and have verified it in the flash descriptor file as well. Also I have unlocked it again using IFDtool as well.

You can also target specific regions for updates using `--ifd -i <region> -N`, for example `--ifd -i bios -N` will make flashrom only attempt to write and verify the BIOS region (without -N flashrom will attempt to verify the entire chip contents).

-        Sure I will try with -N option. I have tried it without the N option and Bios section alone,It failed to erase. I could see from the logs BIOS region SMM protection is enabled and changing it to writable at Bios control failed(Warning: Setting Bios Control at 0xdc from 0xab to 0x89 failed).It remains with oldervalue.


On Sun, Oct 18, 2020 at 2:42 PM David Hendricks <david.hendricks@gmail.com> wrote:
On Sun, Oct 18, 2020 at 8:52 AM Balaji Sivakumar <shivbalaji1985@gmail.com> wrote:
Thank you Peter for the details. Yes it is identifying it as opaque flash chip. We are able to completely read it but erase fails.

There is some documentation in the tree to help explain the "opaque flash chip": https://review.coreboot.org/cgit/flashrom.git/tree/Documentation/mysteries_intel.txt#n8

I understood from the logs of flashrom that SMM protection is enabled. Working on it to disable it.

You will also need to enable host CPU write access to other regions you with to be writeable. From your earlier e-mail it appears that you've already done this for the ME region, however you'll need to do it for IFD and other regions you wish to update. Be advised, however, that *not* locking certain regions may cause the ME to behave differently.

You can also target specific regions for updates using `--ifd -i <region> -N`, for example `--ifd -i bios -N` will make flashrom only attempt to write and verify the BIOS region (without -N flashrom will attempt to verify the entire chip contents).

--
Balaji