See HERE for a 2.4.32 kernel

Put 'deb http://scratchbox.org/debian/ ./' in /etc/apt/sources.list

apt-get install scratchbox-toolchain-arm-gcc3.3-glibc2.3

Get kernel-2.4.19

Apply stupid__r1.patch

Apply patch-2.4.19-rmk2

Apply linux-2.4.19-rmk2-5mx2.patch

Apply tim.patch

export PATH=/scratchbox/compilers/arm-gcc-3.3.4-glibc-2.3.2/bin/:$PATH

make mrproper

copy linux-2.4.19.config to .config

make oldconfig
select N for Thumb and the correct keyboard for your psion

make dep

make Image

Mostly this seems to work - I'm having a problem with the poweron/poweroff button