On 6 August 2013 11:05, Rob Herring <[email protected]> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 08/05/2013 04:41 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.
>
> A DTB should not be tied to a kernel version. I realize that is a
> reality for some boards, but lets not encourage that. There are also
> plans to remove dts files from the kernel.
>
>>
>> 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.
>
> If /boot/dtb is THE dtb to use, does more than that need to be
> specified (at least from a bootloader perspective).

If I understood you correctly, that'd be needlessly limiting one image
to one board.

Consider an SD Card + CONFIG_ARCH_MULTIPLATFORM kernel you can pull
out and plug in to use on a variety of different boards, the
bootloader would need to identify the correct dtb and pass it to the
kernel.

U-Boot is bound up with compile-time decisions about targeting a
single board at the moment, but if we're talking about long term
decisions like /boot/dtb/ just like ARM isn't the only consideration
U-Boot is not the only bootloader.

Once kernels capable of running a single binary on many platforms are
common (they're already workable) pressure for the bootloader to do
likewise will increase.  So it'd be a shame to block that by choosing
a dtb convention that assumes there's only one on the image.

-Andy

_______________________________________________
cross-distro mailing list
[email protected]
http://lists.linaro.org/mailman/listinfo/cross-distro

Reply via email to