Not sure about erasing all of it, but it is (or was) certainly possible to delete enough of it to brick a motherboard https://www.phoronix.com/news/UEFI-rm-root-directory
this post was submitted on 27 Apr 2024
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Pretty sure you can brick your system real quick using efivarfs
https://docs.kernel.org/filesystems/efivarfs.html
some systems dont let you write but some do.
Theres a similar system i was messing with to read and write the firmware code... reading through this may be informative.
efivars should let your change any bios/uefi settings if thats what youre looking for.
Modern versions of Linux don't let you erase it so easily
thank you! I think this is what needed to explore
It is not my level to edit these things, I'm just Linux newbie exploring the possibilities.
But I still can't wrap my head over dd not being able to wipe a storage device out, despite being described as a "low level tool that can write zeroes to targets" in the discussion I viewed online.
The bios isn't like a regular storage device presented to the kernel for mounting.
Dd can’t overwrite a burned cdr either. If the thing you wanna mess with is read only there’s no way to use it as a dd of.
but CD-R aren't rewrite_able because of their physical property not because protected
that's true, but in both cases the ability to write data simply isn't there.
It resides on the MB itself in a separate chip, so no, although there are probably tools to make it possible.
what about this answer ? Is it outdated ? According to it, UEFI could be mounted like a flash drive I understand ?
They should still be possible. It’s not clearing the BIOS though, it is clearing variables loaded into the BIOS. The OS needs to be able to write to them. A good one limits what an OS can write or rebuilds them, a bad one bricks.
hmm, so this is not a constant thing among BIOSes and UEFIs
I'm just curious about what software was used to make this image.
I don't know I got it from this post by the ByteByteGo Youtube Channel:
https://www.youtube.com/post/UgkxNpwmgzai2O_tUa-b5yeLzLjh_OHs4vDY
On the description for this video they state:
Animation tools: Adobe Illustrator and After Effects.
Only if your device supports software flashing, likely not.
It used to be
You can mount the efi partition, but I don't think you can usually mount the uefi or bios. I've only ever edited vbios, and haven't done so in quite some time, but I remember needing to clamp the vbios chip. Dunno if motherboards make their bios chips more accessible, but I kinda doubt it.
Some motherboard support starting bios/uefi updates from a booted OS, so there might be a vector to be found there.
Usually not, but some devices can
No, you need efibootmgr to erase your UEFI.