[U-Boot] [PATCH] Enable thumb build to reduce build size of u-boot.kwb.

[Stefan Roese]

On 04.06.2018 07:12, Stefan Roese wrote:
> On 03.06.2018 23:23, Vagrant Cascadian wrote:
>> On 2018-06-03, Chris Packham wrote:
>>> On Mon, 4 Jun 2018, 7:39 AM Vagrant Cascadian, <vagrant at debian.org> 
>>> wrote:
>>>
>>>> Without this, u-boot.kwb overlaps where the u-boot environment is
>>>> stored, and updating the environment can break u-boot and vice versa.
>>>>
>>>>    https://bugs.debian.org/897671
>>>>    https://lists.denx.de/pipermail/u-boot/2018-May/327497.html
>>>>
>>>> Signed-off-by: Vagrant Cascadian <vagrant at debian.org>
>>>> ---
>>>>
>>>>   configs/sheevaplug_defconfig | 1 +
>>>>   1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/configs/sheevaplug_defconfig 
>>>> b/configs/sheevaplug_defconfig
>>>> index 608e05e64e..d77d198f18 100644
>>>> --- a/configs/sheevaplug_defconfig
>>>> +++ b/configs/sheevaplug_defconfig
>>>> @@ -36,3 +36,4 @@ CONFIG_USB=y
>>>>   CONFIG_USB_EHCI_HCD=y
>>>>   CONFIG_USB_STORAGE=y
>>>>   CONFIG_LZMA=y
>>>> +CONFIG_SYS_THUMB_BUILD=y
>>>> -- 
>>>
>>>
>>> Stefan sent a patch to move the environment for openrd is it worth doing
>>> that instead?
>>
>> Moving the environment breaks compatibility with older saved
>> environments, so seems like something that should be done as a last
>> resort, in my opinion, since upgrading the bootloader can result in an
>> unbootable system if they depend on the environment.
>>
>> Enabling THUMB significantly reduced the size of the image, which should
>> reduce having to play whack-a-mole every few releases as u-boot
>> inevitably tends to grow in size over time... at least for a while.
> 
> Yes, if THUMB is not enabled for those Kirkwood based boards, please
> add support for it. This should give us enough space to add DT and
> DM in the releases.

BTW: Please add a more descriptive patch subject next time, so that
we can better scan the patch content via the subject. Something
like this would be good in this case:

arm: kirkwood: Enable THUMB mode on sheevaplug to reduce the image size

Thanks,
Stefan