On 08/05/2013 03:41 PM, Dennis Gilmore wrote:
Hi all,
As part of the unified features in u-boot thread I said that I would work to get distros to agree to a common location that u-boot will be able to assume exists for it to transparently load dtbs from for us.
I would like to propose /boot/dtb/
I think it needs to be in /boot/ to allow for booting from systems with / and /boot on separate partitions. I believe Ubuntu and hence Debian put them in /lib somewhere today. Fedora puts them in /boot/dtb-<kernel version>. im not sure where the other distros put them.
I think that until they are decoupled from the kernel Fedora would have /boot/dtb be a symlink to the latest installed kernel. once its decoupled it would be the location where the dtbs are installed.
A symlink-to-the-latest-version doesn't seem that useful. If DTBs are tied to a particular kernel version (and in many cases they are today), then bootloaders/... will *have* to access /boot/dtb-${kernel_version} in order to pick up the correct DTB. As such, /boot/dtb itself won't ever be used.
Related, all of this pre-supposes that the DTBs are stored in the filesystem and installed via distro packages. On some systems (Calxeda?), I believe they're provided by firmware (i.e. are stored in flash), so are already in memory by the time e.g. U-Boot runs, and hence have no disk location.