[U-Boot] [Reproducible-builds] [U-Boot, v2] Reproducible U-Boot build support, using SOURCE_DATE_EPOCH

[Andreas Bießmann]

On 08/25/2015 11:55 AM, Vagrant Cascadian wrote:
> On 2015-08-25, Andreas Bießmann wrote:
>> On 07/28/2015 05:00 PM, Tom Rini wrote:
>>> On Sun, Jul 26, 2015 at 06:48:15PM +0200, Paul Kocialkowski wrote:
>>>> In order to achieve reproducible builds in U-Boot, timestamps that are defined
>>>> at build-time have to be somewhat eliminated. The SOURCE_DATE_EPOCH environment
>>>> variable allows setting a fixed value for those timestamps.
>>>>
>>>> Simply by setting SOURCE_DATE_EPOCH to a fixed value, a number of targets can be
>>>> built reproducibly. This is the case for e.g. sunxi devices.
>>>>
>>>> However, some other devices might need some more tweaks, especially regarding
>>>> the image generation tools.
>>>>
>>>> Signed-off-by: Paul Kocialkowski <contact at paulk.fr>
>>>
>>> Applied to u-boot/master, thanks!
>>
>> This commit breaks build on non GNU hosts (like OS X and persumably
>> other *BSD hosts). Before, those hosts where supported, so for me this
>> has to be fixed for 2015.10
>>
>> We need a) some mechanism to search for the GNU date variant or b) some
>> wrapper to provide the correct output on those host machines.
>>
>> I vote for a), it is acceptable to have the GNU date available but we
>> should error on 'no GNU date available'. Furthermore we need to have the
>> date command exchangeable by e.g. gdate, gnudate, ... maybe with full path.
> 
> There was a proposed patch which only uses the GNU date extensions if
> SOURCE_DATE_EPOCH environment variable is set, would this sufficiently
> address your concerns, at least for the short term?
> 
>   Message-Id: <1438337042-30762-1-git-send-email-judge.packham at gmail.com>
>   http://lists.denx.de/pipermail/u-boot/2015-August/221429.html

thanks for the pointer, normal builds work with that change.

Andreas