Bare metal toolchain for A15

[William Mills]

All,

I need to supply a Linaro toolchain "aligned" (same source code) 
bare-metal compiler to a group doing benchmarking on A15.

First off my assumption is that we will write our own boot and semi 
hosting code.  (semi-hosting for TI emulators/simulators is different 
than ARM RDI semi-hosting.)

I was planning on looking at the two toolchains here[1] and here [2]:
[1] https://launchpad.net/linaro-toolchain-binaries
[2] https://launchpad.net/gcc-arm-embedded

I was then going to build a hybrid that was newlib based but appropriate 
for armv7-a (instead of cortext-m3) and maybe even -mtune'ed for A15.

However looking at the gcc-arm-embedded release more[3] I see that it 
supports ARMv7-R.  It supports both thumb and non-thumb modes, both 
softfp and hardfp ABIs.

What would I really gain by building my own?  For app code the user 
should be able to add -mtune=cortex-a15 and still be compatible with the 
pre-built R4/R5 libraries.  The only performance difference should be in 
the library code and that should be only pipeline tuning if I understand 
the difference between armv7-a and armv7-r correctly.

Am I missing something?  Should I build my hybrid anyway?

[1] https://launchpadlibrarian.net/88152755/readme.txt

[BTW: has the below project been obsoleted by the gcc-arm-embedded one? 
  Perhaps gcc-arm-embedded should be referenced in the description of 
the page below.
https://launchpad.net/linaro-toolchain-unsupported ]

Thanks,
Bill