Kernel for S/390 and hercules

So now you have a cross-compiler, now to get a kernel for your mainframe!

Download kernel source, unpack and configure:

wget http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.2.6.tar.bz2
tar jxf linux-3.2.6.tar.bz2
cd linux-3.2.6
make ARCH=s390 CROSS_COMPILE=/opt/s390/bin/s390-ibm-linux- defconfig

Now you have your kernel source setup for building a S/390 kernel with the default kernel configuration. You can now customize the configuration by running:

make ARCH=s390 CROSS_COMPILE=/opt/s390/bin/s390-ibm-linux- menuconfig

For example, some drivers defaults to being built as modules, that you might like to have in your kernel image instead.

Now build the kernel (add -j2 or more if you have a SMP system to speed up the compilation):

make ARCH=s390 CROSS_COMPILE=/opt/s390/bin/s390-ibm-linux- 

The kernel should build successfully, and you should have a kernel image in
arch/s390/boot/image ready for IPL on your mainframe.