Cross-compiling gcc, glibc and all that. (Part II – the script) Wednesday 18th July 2007

So here it is, the script that does it all. Although it is a shell script, I thorougly recommend not running it, but cutting and pasting it, section by section, into a terminal session so that you can fix up any environmental issues that cause it to fall over. There are some paths at the top of the script that you probably want to fix before starting. I ran the whole script on a PIII system and it churned through the entire process in just under an hour.

The basic procedure is to install a “cross” binutils (gas, ld, etc.), install kernel headers and glibc headers into a fake x86_64 system root, then compile a minimal gcc cross compiler without making any target libraries, then use this to compile a glibc for the target platform, then use the resulting glibc to build a full gcc with c++ support and the required target libraries. The reason for making two gcc is that making a full gcc requires some parts of the target glibc to be built with the cross-compiler that you haven’t yet built.

The script has six steps and three “fudges”, which I consider to be quite an achievement on the fudge count.

Important note: building glibc with nptl (the native Posix threads library for linux) does not work with the “stage one” minimal gcc. This is a big problem as glibc-2.6 only comes with nptl, as far as I’m aware, and you are stuck. glibc-2.5 has an add-on for the “old” linuxthreads support and you can build this with the “stage one” gcc compiler. Once you’ve built the full gcc with the “old” threads supported glibc-2.5 you can go back and build a full version of glibc-2.6 with nptl with this gcc. Once you’ve done this, if you’re feeling uncertain, you can go back and completely rebuild a full gcc on top of this glibc-2.6, just in case it makes a difference. Once you’ve done this, if you’re feeling very uncertain, you can completely rebuild glibc-2.6 with the brand new gcc, just in case in makes a difference. Once you’ve done this…

I’d really love to find a fix for getting the whole process to work without having to fall back to an old version of glibc. It feels (ha!) even more hacky than the rest of the process feels.

You’ll need:


Like all such documents, this list will seem out of date before I’ve posted. By all means try the process with gcc 4.4, linux 2.8, glibc 2.7 and binutils 2.18, but the fudges will probably all have to be updated before it works.

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