On 2020-04-27, Simon South wrote:
> Vagrant Cascadian <vagrant@debian.org> writes:
>> With your current layout, parts of the bootloader may be written to the
>> same offsets as files in your first partition...
>
> Yes, my mistake. Thanks for pointing that out.
>
>> You really want to have the loader1 (start sector 64, 2.5MB size) and
>> loader2 (start sector 16384, 4MB size) partitions...
>
> I'm not sure how literally you meant this to be interpreted, but after a
> bit of experimentation it seems the most sensible arrangement for now is
> just to have a single partition starting at sector 32,768 for the root
> filesystem. This is because

That also should work fine.


> - If real partitions are created for the bootloader stages and the
>   trusted firmware, U-Boot will fail to start the OS (with "Unrecognized
>   filesystem type") when it scans for bootable partitions. (It probably
>   ought to just skip over partitions without a recognizable filesystem,
>   but it doesn't seem to behave that way.)

It's possible to mark the partition as bootable (I think "ESP Boot" or
something like that).


> - It seems Guix System does not yet support having /boot on a separate
>   partition and will fail at startup if the store isn't available on the
>   same filesystem as extlinux.conf. Consequently reserving 112 MB for a
>   separate boot partition accomplishes nothing.

Right; I wouldn't suggest using such a tiny boot partition anyways (I
think they suggest a 112MB /boot ?).


> At least this way the root filesystem is safe from being overwritten by
> the bootloader, and as Guix's support for multiple partitions improves
> over time it'll be possible to more closely follow Rockchip's
> conventions.

Yeah, anything after sector 32768 is, in my opinion, fair game to do
whatever you want with. :)


>> It would be nice to eventually be able to create installer images for
>> aarch64/armhf...
>
> Yes, absolutely. In the meantime just making available a
> minimal-but-complete image for writing to a microSD card would be a big
> help to people looking to get started quickly with Guix on the ROCK64.

I'm tempted to make armhf and aarch64 one-off images using
linux-image-arm64-generic and linux-image-arm-generic kernels, and
include instructions for updating the bootloader, to support an
arbitrary number of different systems... this should be doable.


live well,
  vagrant