[RFC PATCH 0/4] Introduce global.bootm.root env var for booting via PARTUUID

[Sascha Hauer]

On Tue, Jun 30, 2020 at 03:48:30PM +0200, Robert Karszniewicz wrote:
> This patch introduces a new env var which specifies which device
> is the rootfs device to be used in Linux, passed to Linux via bootargs,
> identified by the rootfs partition's PARTUUID.
> 
> global.bootm.root supplements global.bootm.appendroot, in that it overrides
> appendroot's naïve default, which picks the partition that the kernel resides
> on (global.bootm.image).
> 
> I don't know if it is the right way, or a good way, but this is the shortest
> and simplest way that I've found.
> 
> What do you think of this? And is it generally something that would be
> accepted, or is this out of scope for barebox?
> 
> Example:
> detect mmc2
> global.bootm.image='/mnt/mmc2.0/zImage'
> global.bootm.appendroot=1
> global.bootm.root='/mnt/mmc2.1/'

Why do you pass the standard mount path here? I would expect /dev/mmc2.1.

In 4/4 you mount the root device. I think this should be avoided as it
only works when barebox has support for the rootfs, i.e. it doesn't work
for XFS or the like.

Ok, fsdev_set_linux_rootarg() is tied to a filesystem, so maybe we need
something similar for a cdev.

Generally I think barebox should support this usecase, but I am not
convinced the approach you took is the right API.

Sascha

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