[U-Boot] [PATCH] wandboard: add pxe support, set default boot command like highbank

[Rob Herring]

On Fri, Aug 2, 2013 at 4:14 AM, Stefano Babic <sbabic at denx.de> wrote:
> Hi Rob, Dennis,
>
> On 01/08/2013 19:19, Rob Herring wrote:
>> You both are missing the point. This patch doesn't address the problem,
>> but does highlight it.
>
> I am aware of it - I have already pointed out that we get many patches
> that have increased the default environment to something hard to
> maintain. This patch makes it more obvious.
>
>> The distros want to get out of having to know the
>> u-boot environment details for every single board and need some level of
>> standardization across platforms. The distros should only have to
>> specify "boot the kernel at path/name X on device Y." They should not
>> need to know what address to load the kernel to, but only that
>> $kernel_addr_r is already setup. Variables are the first step. The
>> second step is standardizing the boot commands.
>
> I understand the point - but is the way to hard code together with
> u-boot the right way ? Do we have some other possibilities to do this ?
>
> Maybe can be mkenvimage a solution (tools/mkenvimage) ? It creates an
> environment image from a simple ASCII text. The resulting image could be
> concatenated together with u-boot and in CONFIG_EXTRA_ENV_SETTINGS we
> could have for all boards a way to load it. Only a first idea, but as we
> recognize the issue, any idea to solve it ?

I definitely agree that we should move this out of C code and support
standalone text files as input. IIRC, CONFIG_EXTRA_ENV_SETTINGS is
replaced by any separate environment. I think it also needs to support
being merged with a separate environment.

I would like to be able to simply say to enable distro support, add a
config-distro.h to your board config, include a common set of
environment commands to search boot devices for a kernel, and set a
TBD list of env variables to board specific values. If there is a
common set of files geared toward distro support, then it is easy for
distros to submit patches against them and for board maintainers to
know what the requirements are for distro support.

Rob