On Tuesday, April 5th, 2022 at 9:42 AM, Nico Huber wrote: > You could test if communication is 100% reliable, e.g. read once, verify > multiple times. Also, measure the voltage at the flash chip.
Hello Nico, Just an update as I think my second issue has also been solved, and maybe this can be of use to others. First I connected an external power supply to the Raspberry Pi, this did not change anything, but this connection was still reliable, I tried to verify a read 20 times in a row without problems. I then disconnected the 3.3V connection and tried to power the chip from normal PSU as explained in the flashrom ISP wiki, but this seems not to work with this board, as I was unable to communicate with chip no matter what I did. Because of my ignorance, I did not mention or consider that the motherboard is a Gigabyte with DualBIOS (GA-H270N), I just checked the chips were identical and didn't think more of that. With this board there is no way to control anything about the DualBIOS function, e.g. by switch or using jumpers. The motherboard has been in a reboot loop for over a month, and before using an external programmer, I tried the procedures found online related to these boards, e.g. shorting pins, resetting CMOS etc. to no avail. Until now I have only been trying to write the M_BIOS chip, but then I tried the B_BIOS chip and lo and behold, the flash was successful. No problems with disabling block protection and erase function 0 was able to erase the chip. After powering on, the system rebooted 1 or 2 times and then booted normally. I think the M_BIOS was overwritten automatically with content from B_BIOS during the inital reboots, but I need to investigate this further. Flashrom requires a patch for '-p internal:dualbiosindex=' to work with this board, I will submit it after testing everything works. After doing some research, I have found out that on boards with multiple flash chips, you should connect 3.3V to "Chip Select" (CS) of the other chip while flashing. Does this sound right? Would flashrom be able to disable block protection on M_BIOS if I had done this? I almost want to to take apart the whole system again and try just to find out. Best regards, Pete Smith _______________________________________________ flashrom mailing list -- flashrom@flashrom.org To unsubscribe send an email to flashrom-le...@flashrom.org
