[U-Boot] [PATCH V2] add README.distro file

[Stephen Warren <swarren@wwwdotorg.org>]

On 01/11/2015 02:45 AM, Ian Campbell wrote:
> On Sun, 2014-12-28 at 09:26 +0000, Ian Campbell wrote:
>>> +boot_scripts:
>>> +
>>> +  The name of U-Boot style boot.scr files that $bootcmd searches for.
>>> +
>>> +  Example: boot.scr.uimg boot.scr
>>> +
>>> +  (Typically we expect extlinux.conf to be used, but execution of boot.scr is
>>> +  maintained for backwards-compatibility.)
>>
>> I'm slightly concerned by the implied deprecation of the boot.scr method
>> here, since at least Debian uses boot.scr exclusively and not the
>> extlinux stuff. Will boot.scr be maintained going forward or are there
>> plans to eventually remove it?
> 
> Can someone confirm that there is no long term plan to drop boot.scr
> support?

extlinux.conf *is* the standard Linux boot process that
config_distro_bootcmd.h enables. boot.scr is *not*. The whole point is
to introduce a new simple standard that works the same everywhere (for
Linux: across boards, across distros, across bootloaders).

I would expect boot.scr support to be maintained indefinitely for any
board the currently supports it. I certainly know of no plan to remove
any existing support for it, and am not going to make such a plan.

When adding support for config_distro_bootcmd.h to any board that
doesn't support boot.scr already, I would not expect boards to want to
start supporting boot.scr; it's a legacy method as far as
config_distro_bootcmd.h is concerned.

(config_distro_bootcmd.h should be updated to make the boot.scr support
optional, so it doesn't get enabled unless specifically requested, when
boards add #include <config_distro_bootcmd.h>).

Supporting boot.scr may well be useful for a variety of non-Linux or
legacy environments, so I'm not proposing anyone rip out support for it.
Simply not add support for it if it hasn't been necessary already.