Re: 2 partition setup where /boot partition contains more than just kernel and initramfs images.

[Colin Walters <walters verbum org>]

On Wed, Oct 21, 2015, at 05:32 AM, Paeglis Gatis wrote:

Hello,

On u-boot based systems there often might be other files that need to be updated together with kernel/initramfs updates - like device tree blobs (actually several of these if you want to 

reuse the same kernel on several devices), uEnv.txt or compiled boot script, and maybe even second stage bootloader or what not. Updating only kernel/initramfs and skipping all these

other files might result in system that does not boot.

 

We could have build-time options to enable some things like this.  Or even just unconditionally

do it if the files exist.  Are there any "defacto" standards for the locations of DT blobs etc.?

 

 

One way to workaround this issue is to keep your whole sysroot on a single partition. Patch for this was introduced in https://github.com/GNOME/ostree/commit/598530daf45a8bcb3be171732569b8aad0f4345d , but there are several disadvantages in this approach in my opinion:

 

One thing we could do as well is canonically store kernel/initramfs in /boot to avoid

duplication.  The reason this isn't done by default is that it would require introducing a messy

special case into the generic "git-like" filesystem layer.

 

- is this relevant for grub based systems too or there having only kernel/initramfs on /boot is sufficient?

 

Possibly yes- there are things like boot splash images.  Currently the status quo in at least

Fedora/Anaconda/OSTree is that Anaconda lays down all these additional files in /boot, then

OSTree never touches them again.

 

But I can certainly imagine wanting to be able to atomically update the boot splash

with major version updates etc.