Hello,
I am trying to test the secure boot feature in the iMX9 11x11 EVK. I have successfully generated a signed image of u-boot and a fuse.bin file for SoC's internal fuses.
The issue is that I would like to test it before burning EVK's internal fuses, that's why I tried to override fuse values' shadow registers. I'm not sure if I have an accurate idea of shadow registers. As far as I have undestood, in U-boot prompt I can change the read fuse values to another values with "fuse override" command, this changes are temporary so once that I reset the board the overriden values are erased (Are they RAM variables or something similar?).
The problem comes when I try to override those fuses:
And if I take a look where I consider that this command is called in U-boot source code (drivers/misc/imx_ele/fuse.c):
I don't know if in iMX8ULP fuse overriding is permitted or not, I guess it is not, but I have undestood that in iMX9 this feature is available. I say so because of information given in the reference manual (page 226 for example):
So my question is as follows, is fuse overriding for testing purposes available in iMX9 or not?
Best regards,
Gorka.
Hello AldoG,
Thank you for your reply. I see that it is not supported. But is this feature available in imx9 and the driver hasn't been developed yet or it is not even present that feature?
As I cannot verify the process without burning fuses, is it any way I can verify that the image is signed correctly? Maybe emulating the boot process in my computer?
I mean, computing the hash of the bootloader and comparing it to the decrypted signature of the image using the public key?
I would like to test the key generation and image signing somehow without burning the fuses of the EVK yet.
Best regards,
Gorka.
