Hi,

Some comments about current hardfp RPM optflags has been that we have
-mno-thumb . And some vendors might want to optimize some things for
thumb in terms of memory size. So I'd like to preempt this issue
before we run into it in deployment by vendors - and help by having a
standard set of optimized packages.

Thumb2 is problematic on some silicons, due to
http://cateee.net/lkddb/web-lkddb/ARM_ERRATA_430973.html - and this
includes Nokia N900 and possibly other boards. But it is also very
useful when it comes to memory and cache size of the running system.

My proposal is to add on top of the 2 (armv7nhl, armv7hl) hardfp
architectures, RPM these definitions:

armv7thl: -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 -mthumb
armv7tnhl: -march=armv7-a -mfloat-abi=hard -mfpu=neon -mthumb

armv7thl would be install compatible with armv7hl
armv7tnhl would be install compatible with armv7thl, armv7nhl

The argument against just flicking armv7hl from -mno-thumb to -mthumb
is that we lose the current ARM reference device (N900) and possibly
make MeeGo ARM undeployable on other boards. As well as potential bugs
from compiling entire system for thumb (as Ubuntu had done, with a lot
of effort)

This will not require an additional OBS scheduler on top of the hardfp
one, as we intend to generate these packages using same way we
generate armv7nhl packages, by selecting some packages that benefit
from the optimization(s) and generate additional packages for the
targeted architectures.

Package management & Image creation will then take the proper package
matching the architecture, allowing for an optimized experience for
target boards.

The baseline for applications is -still- armv7hl and should be the
primary target for SDKs and OBS. These additional flags allow
flexibility.

If there's no objections, I'll submit this towards the various places
the archs needs to be supported in.

BR
Carsten Munk
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