[U-Boot] [U-Boot, V4, 10/13] spl: add support for alternative boot device

[Stefan Roese <sr@denx.de>]

On 19.11.2015 12:19, Nikita Kiryanov wrote:
> Hi Tom,
>
> On Wed, Nov 18, 2015 at 05:33:20PM -0500, Tom Rini wrote:
>> On Sun, Nov 08, 2015 at 05:11:51PM +0200, Nikita Kiryanov wrote:
>>
>>> Introduce spl_boot_list array, which defines a list of boot devices
>>> that SPL will try before hanging. By default this list will consist
>>> of only spl_boot_device(), but board_boot_order() can be overridden
>>> by board code to populate the array with custom values.
>>>
>>> Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
>>> Cc: Igor Grinberg <grinberg@compulab.co.il>
>>> Cc: Tom Rini <trini@konsulko.com>
>>> Cc: Simon Glass <sjg@chromium.org>
>>> Reviewed-by: Tom Rini <trini@konsulko.com>
>>> Reviewed-by: Simon Glass <sjg@chromium.org>
>>
>> So, a problem with this patch is that we push the x600 board, which is
>> an 8KiB SPL target, over the line.  I feel like maybe we need a
>> follow-up patch that makes announcing depend not on libcommon (which
>> x600 needs) but something else to know that there's a reason to
>> announce.
>
> Based on the content of your reply I'm guessing you're referring to the
> next patch, not this one.
>
> I suppose that announcing can be made into an optional feature. However,
> I also think that since printing is an optional feature that can greatly
> increase binary size, it shouldn't be coupled with other, often
> non-optional libcommon features the way it currently is via
> CONFIG_SPL_LIBCOMMON_SUPPORT. The best fix in my opinion would be to
> implement a way to exclude printing support from SPL even if libcommon
> is included (CONFIG_SPL_SILENT that replaces printfs with empty stubs?).
>
> This will also make it possible to remove all those #ifdef
> CONFIG_SPL_LIBCOMMON_SUPPORT checks that appear all over the SPL code.

I think that my recently posted tiny-printf patches:

https://patchwork.ozlabs.org/patch/545034/
https://patchwork.ozlabs.org/patch/545033/
https://patchwork.ozlabs.org/patch/545036/
https://patchwork.ozlabs.org/patch/545035/

can solve this size issue on x600 (and perhaps other) board.

Comments welcome...

Thanks,
Stefan