Strategy for packaging an ARM Cortex-M toolchain

[Eric Smith]

Rob Spanton wrote:
> There are an increasing number of ARM Cortex-M based boards around, and
> I'd like to get a cross-compilation toolchain for them into the Fedora
> repositories.

I hope you're more successful with that than I was.  I found a 
resounding lack of interest when I put an arm-none-eabi binutils up for 
review some time back, in preparation for corresponding gcc and gdb 
packages.

I agree with Ralf that this is a different target than arm-gp2x-linux, 
and should be totally independent of it.  However, there might be 
overlap with the cross-gcc package, which builds a gcc-arm-linux-gnu 
package.  That triple sounds like it is for cross compiling to a Linux 
ARM platform, but note that some of the other triples that they build, 
e.g., c6x-linux-gnu arm-h8300-linux-gnu, are actually for non-Linux 
target platforms, so possibly the gcc-arm-linux-gnu package might be 
suitable for non-Linux ARM Cortex-M3 development.

I've personally had much better luck with the Mentor Sourcery (formerly 
CodeSourcery) distribution of the GNU tools for targeting ARM than with 
the official FSF distribution.  The Mentor Sourcery team seems to be one 
of the largest contributors to maintaining the GCC ARM target, and their 
distribution has bug fixes and such *much* earlier than the official FSF 
distribution.  It was my intent to package the Sourcery toolchain, but I 
didn't push it any further when there was no interest in the binutils.

I'm doing cross-development for a custom board with an Energy Micro 
EFM32GG380F1024, which is a "Giant Gecko" part containing a Cortex-M3 
core, 1MB flash, 128KB RAM, full-speed USB, and a bunch of other 
peripherals.  I started with the original Gecko part because it was the 
only ultra-low-power ARM chip with a decent amount of RAM back in 2010, 
but there may be a few others getting close to it now.

Eric