Building armel on arm64

[Adrian Bunk <bunk@debian.org>]

On Wed, Jun 27, 2018 at 08:03:00PM +0000, Niels Thykier wrote:
>...
> armel/armhf:
> ------------
> 
>  * Undesirable to keep the hardware running beyond 2020.  armhf VM
>    support uncertain. (DSA)
>...

I'd like to get a clear picture regarding the situation of building 
armel for buster on arm64, ideally moving it to arm64 hardwre soon.


1. What issues are considered possible problems for moving building
   armel from 32bit v7 hardware to 64bit v8 hardware?

ARM has some history of adding new functionality in new versions of 
their architecture that gets deprecated in the next version of their 
architecture.

The armel baseline (currently armv5te) is low enough that several
of the issues with running armhf code on arm64 are not present
when running armel code on arm64.

If anyone sees potential blockers for building armel on arm64,
especially ones that are not present for building armhf on arm64,
please speak up now.


2. What level of testing has been done before building armhf on arm64?

64bit arm-arm-01 has started participating in building armhf for 
unstable and experimental.

I don't want to do less testing for armel than has been done for armhf 
prior to doing that, what testing had been done for armhf on arm64 
building prior to doing it on a buildd?


3. Starting to build armel on arm64

Depending on the answers to the questions above I would like to
setup building armel on arm64, perhaps on the same arm-arm-01.


Thanks
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed