ubuntu-phone team mailing list archive

[Simon Fels <simon.fels@xxxxxxxxxxxxx>]

On 07.09.2015 17:21, Oliver Grawert wrote:
> Am Montag, den 07.09.2015, 14:57 +0100 schrieb John McAleely:
>
> > Are these the two options we have? What pros and cons are there for
> > each?
>
> do you actually know (did anyone test) if hybris would get along with
> running in 32bit on the ubuntu side while the container is 64bit ? i
> suspect there needs to be some syscall translation between the two
> hybris sides ...

I doubt that will work. At least not for libGLES, libEGL, .. as they 
don't use proper length-defined types like uint16_t. Also from what I've 
seen we can't promise which HAL libraries we get in 32 / 64 bit and 
which only in 32 bit and which only in 64 bit. The Android CDT defines a 
small subset of Android libraries which must be available in both 
variants but that isn't enough for our purpose. Also I am not entirely 
sure if the HAL API is reliable in terms of well defined types.

> otherwise yes, it would be a good interim if we could use a 32bit rootfs
> with 64bit container ... apps wouldnt be able to address the full ram
> though (afaik thats limited to 3GB with armhf) so it wouldnt be a
> permanent solution.
>
> long term someone needs to make arm64 images work anyway indeed.

For the near term we need a solution to handle both as we will have to 
support applications having different types at the moment. We need to 
find a way to ensure that all future applications in the store will get 
a 64 bit variant as well to prevent us from having to support 32 bit 
apps forever and can easily switch to 64 bit only later once we don't 
offer any other devices anymore.

regards,
Simon