Cross Compilation Under Mac OS X on PowerPC

This page describes a method for cross-compiling Linux/mac68k (2.2) and Linux/m68k (2.6 and later) kernels. Versions 2.3, 2.4 and 2.5 are best avoided on Macs.

These tools require Mac OS X 10.3 or later running on a Power Mac. An Intel Mac with the Rosetta PowerPC emulator is not recommended (but YMMV). Also required is the Mac OS X SDK installed from your XCode CD or Mac OS X DVD.

First, obtain the necessary files

These instructions assume that certain files can be found in your Desktop folder. So you'll want to vist the FTP site and download the cross compilers tarball, m68k-xcompilers-for-os-x. Also download the Linux/mac68k kernel build patch, linux-2.2.25-darwin-build.diff (unless you are going to compile the Linux/m68k kernel, which instead requires linux-2.6.x-darwin-build.diff).

Install the cross-compilers in /opt

Create and mount a disk image

A case sensitive volume is required for building the kernel.

At this point, the instructions diverge depending on whether you are building Linux/mac68k or Linux/m68k. Keep reading for mac68k, or click here for m68k.

Instructions for Linux/mac68k (Linux 2.2 branch)

Install gawk

Running make menuconfig or oldconfig etc requires GNU awk and will not work with the BSD awk.

Download sources

Grab the kernel sources as per the usual procedure (no password).

Patch sources

This patch permits the kernel to build under Darwin, and also creates a kernel configuration suitable for Macs (essentially the Debian one, updated).

Set PATH variable

For the Linux 2.2 kernels we use gcc 2.95.4 (actually 2.95.3 with Debian's patches).

The file drivers/char/defkeymap.c was removed from the mac68k CVS and so we have a hacked-up loadkeys just for generating this (though we could instead use the defkeymap.c from the kernel.org source).

Place gawk, depmod.pl and loadkeys in the PATH (depmod.pl is from the busybox package, and loadkeys comes from kbd).

Compile

Next, create the config file.

Lastly, compile the kernel, either the easy way (which conveniently creates a modules tarball),

or the traditional way.

Instructions for Linux/m68k (kernel.org sources)

Install gettext

As of linux-2.6.12, the kbuild system depends on gettext.

Set some variables that help locate gettext.

Download sources

Grab the kernel sources from kernel.org.

Patch sources

This patch permits the kernel to build under Darwin.

Set PATH variable

Choose a gcc cross compiler. For compiling kernel version 2.6.15 and later, gcc version 3.2 or later is required. However, FSF gcc 3.3 and 3.4 were installed in an earlier step.

Put the patched depmod.pl in the PATH and it will create modules.dep.

Compile

First configure the kernel,

and then build it (add -j3 for building on a dual processor Mac).

Finally, install the modules into /tmp/lib/modules for easy tar'ing.