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On Friday, 3 July 2020 03:05:34 BST Andrew Udvare wrote: |
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> On 02/07/2020 06:56, Peter Humphrey wrote: |
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> > But then, |
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> > # bootctl set-default 30-gentoo-5.7.7.conf |
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> > Failed to update EFI variable: Invalid argument |
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> |
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> Probably the kernel is blocking write access to EFI. This is on purpose |
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> for safety as you can damage your firmware quite easily. systemd-boot |
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> and others do not have this restriction. |
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Is there some way for me to remove this restriction temporarily? |
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> You also should be careful writing to the EFI too much as the NVRAM flash may |
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> not be of high quality. |
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Yes, I do only write to it when I have to. I hope Asus would use decent- |
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quality components though. |
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> https://lwn.net/Articles/674940/ |
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Interesting - thanks. |
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> You can try using `chattr -i` against the files like: |
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> |
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> chattr -i /sys/firmware/efi/efivars/Boot* |
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> |
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> Then you can try with bootctl and others, but this is not guaranteed to |
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> work. |
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Those files were already among the 17 that were mutable. It seems I need to find |
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which of the other 117 files I need to make mutable. |
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> On my ASUS motherboard I haven't been able to write to EFI variables |
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> from within Linux for a long time. I have to add my keys in the BIOS and |
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> set the default in systemd-boot. |
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Looks like I'm in the same boat. Except that setting the default in systemd- |
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boot is exactly what I can't do! |
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> The logic to write to a file in efivars is here: |
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> |
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> https://github.com/torvalds/linux/blob/master/fs/efivarfs/file.c#L15 |
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> |
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> If you use strace with bootctl you'll probably see one of these errno |
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> values. |
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I think what I'm seeing comes from this: |
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if (attributes & ~(EFI_VARIABLE_MASK)) |
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return -EINVAL; |
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Perhaps I should just stop here and revert to setting the default at the UEFI |
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boot-choice screen. |
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Many thanks for your help, Andrew. |
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-- |
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Regards, |
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Peter. |
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