Re: [PATCH 1/2] ARM: Add Kconfig option to use mkimage -T kernel_noload

[Tim Bird <tim.bird-mEdOJwZ7QcZBDgjK7y7TUQ@public.gmane.org>]

On 02/29/2012 10:14 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 08:58 Wed 29 Feb     , Stephen Warren wrote:
>> Jean-Christophe PLAGNIOL-VILLARD wrote at Wednesday, February 29, 2012 5:30 AM:
>>> On 17:03 Tue 28 Feb     , Stephen Warren wrote:
>>>> uImage files typically encode a single absolute load and entry address.
>>>> This is inconvenient when attempting to share that uImage across multiple
>>>> SoCs with different physical RAM addresses. Recent versions of mkimage
>>>> implement a "kernel_noload" image type which encodes no absolute load
>>>> address, and a relative entry address. This works well for uImage-wrapped
>>>> ARM zImages, since they are relocatable.
>>>>
>>>> This is enabled by commit b9b50e89d317c58becd0e2d7fac2e21e3a81dd0a
>>>> "image: Implement IH_TYPE_KERNEL_NOLOAD" in U-Boot.
>>>>
>>>> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>>> ---
>>>> I assume I should put this into the ARM patch tracker if it's OK?
>>>
>>> Again a new option for uImage no why not just boot the zImage
>>>
>>> in this case the uImage is useless
>>
>> U-Boot doesn't support zImage at present.
>>
>> A patch was posted to support it at least for ARM, but needed a little
>> work before it could be committed.
> Sorry I see no advantage to have the uImage build by the kernel anymore as
> we have a relocatable zImage
> 
> I'll even drop its support

This seems at least premature, and possibly ill-advised in general.
There are lots of U-Boot images out in the field, many of which that
are rarely updated. A lot of workflow will be disrupted unnecessarily
by a change like this.

Could you wait to drop uImage build support in the kernel until
U-Boot supports zImage, and has worked it's way into the field
for a few years?
 -- Tim

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Tim Bird
Architecture Group Chair, CE Workgroup of the Linux Foundation
Senior Staff Engineer, Sony Network Entertainment
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