On Wed, 6 Apr 2022 14:18:18 +0200 Pali Rohár pali@kernel.org wrote:
Armada 385 contains 64 lines of HD eFuse and 2 lines of LD eFuse. HD eFuse is used for secure boot and each line is 64 bits long + 1 lock bit. LD eFuse lines are 256 bits long + 1 lock bit. LD 0 line is reserved for Marvell Internal Use and LD 1 line is for General Purpose Data. U-Boot already contains HD eFuse reading and programming support.
This patch implements LD eFuse reading support. LD 0 line is mapped to U-Boot fuse bank 64 and LD 1 line to fuse bank 65.
LD 0 Marvell Internal Use line seems that was burned in factory with some data and can be read by U-Boot fuse command:
=> fuse read 64 0 9
LD 1 General Purpose Data line is by default empty and can be read by U-Boot fuse command:
=> fuse read 65 0 9
Signed-off-by: Pali Rohár pali@kernel.org
I am not sure whether this can be used safely on Turris Omnia - there was some issue with voltage or something, I know for sure that burning does not work on Omnia, but I am not sure if the issue also prevents stable reading.
Are the values you read always the same? Even across power cycles?
Marek