On Sun, Mar 27, 2011 at 12:00 PM, Diane Holt holt.diane@gmail.com wrote:
Sorry, I should have been more specific. Yes, a cross-compiler for ARM (we're building for cortex-a8, which is why we're interested in the neon optimizations). As I mentioned, I can't use the one that's available as a debian pkg built by Linaro, because I need to use the toolchain in Scratchbox, which has a rather old libc (in its host_shared/lib), and the Linaro one was built against a very new libc. I checked with scratchbox.org, and there are no current plans to update the host_shared libc, so, if the CS 4.5.1 doesn't have those same neon optimizations, then my only other recourse is to try and build the linaro 4.5.2 myself (since I need this "yesterday" :P ). So I was hoping the build process that's being used to build the cross for ARM would be documented somewhere, so I could do the same steps, just on an earlier Ubuntu (dapper), but I wasn't able to find anything on the Linaro site.
Hi Diane. The toolchain working group has assignees from CodeSourcery, IBM, ARM, and Canonical. We often get access to improvements that CodeSourcery have done internally, and help get those upstream and get them tested by using them in real products such as Ubuntu. CodeSourcery are free to pick up optimisations that Linaro do up in the FSF trunk, such as the NEON improvements that Richard and Ira are working on. The short story is that there's good cross-pollination there.
Regarding building a new cross-compiler, have a look at my cross-build scripts: https://code.launchpad.net/~michaelh1/+junk/cross-build
and especially the cross-gcc directory. This does a single stage cross compiler build against a prebuilt binary sysroot like you have at the moment. Set PREFIX to where you want the compiler to install to and modify SYSROOT and the $(stamp)sysroot-extract rule to point the build at your scratchbox header files and includes.
It'll need a little bit of work. If it turns out, could you send some instructions to the list?
-- Michael