Q: How can I complie Linux kernel for Zaurus ?

A: Follow the below instruction.

You would need the Linux kernel source for the Sharp Zaurus and the
cross-compiling environment both available at Sharp's web site
(http://more.sbc.co.jp/slj/index.asp).
There also is a good documentation to build the kernel
(http://more.sbc.co.jp/slj/source/build_image112.asp).
The cross-compiling environment can be built on RedHat Linux. You will 
need a CompactFlash memory card (>32MB) to update the kernel.

The procedure is as follows:

1. Update your FlashROM image (binary) to 1.12 or 1.13
2. Prepare the cross-compiling environment.
3. Get the kernel source.
4. Configure and build the kernel.
5. Transfer the kernel image to FlashROM.
6. Enable the IPv6 code

Please note that the newly built kernel does NOT support SD cards as
described in the Sharp's document.

The following is the detailed procedures:

1. Update your FlashROM image (binary) to 1.12 or 1.13

The latest FlashROM image and the kernel source code is different from 
the shipped FlashROM image. I recommend that you first update the
binary FlashROM image to the latest version which matches the version
of the kernel you are going to build.
The FlashROM image can be downloaded from
http://more.sbc.co.jp/slj/download.asp
The update procedure is documented in
http://more.sbc.co.jp/slj/download/readme/readme_romimage112.asp
Please read it carefully.
If you use the Windows driver (Intellisync or Qtopia Desktop), you
will also need to update these drivers.

2. Prepare the cross-compiling environment.

The procedures and the links to necessary tools are available in
http://more.sbc.co.jp/slj/source/build_image112.asp
In short, you will need
http://more.sbc.co.jp/slj/tool/gcc-cross-sa1100-2.95.2-0.i386.rpm
http://more.sbc.co.jp/slj/tool/glibc-arm-2.2.2-0.i386.rpm
http://more.sbc.co.jp/slj/tool/binutils-cross-arm-2.11.2-0.i386.rpm
Install them with 'rpm -i' command, and include /opt/Embedix/tools/bin
to your PATH.

3. Get the kernel source.

You can either download the entire source
http://more.sbc.co.jp/slj/source/linux-sl5000d-20020318.tar.bz2
or the patch to ARM-Linux kernel
http://more.sbc.co.jp/slj/source/linux-2.4.6-rmk1-np2-embedix-20011228-sl5000d-20020318.gz
As describe in the Sharp's document, you will also need
linux-2.4.6.tar.bz2
patch-2.4.6-rmk1.gz
diff-2.4.6-rmk1-np2.gz
if you are going to use the patch.

4. Configure and build the kernel.

As the document says, please configure the kernel as follows:
	$ cd linux
	$ make menuconfig
	--> Load an Alternate Configuration File
	input "arch/arm/def-configs/collie"
	select "ok"
	select "Exit"
	Do you wish to save your kernel configuration?  -> Yes
The default configuration does not enable IPv6, so you will also need
to enable it. 
	$ make menuconfig
	--> Networking options
	--> The IPv6 protocol (EXPERIMENTAL)
You can either embed the IPv6 protocol stack to the kernel (displayed
as '<*>') or make it separated as a loadable module (displayed as
'<M>'). I tried the latter.
Now, you can build the kernel.
	$ make dep; make clean; make zImage
I you are going to build the IPv6 code as a module, please do
	$ make modules
also.

5. Transfer the kernel image to FlashROM.

Copy the built kernel (linux/arm/boot/zImage) to an empty CompactFlash 
card. The update procedure is same as the binary update procedure
except that you use the 'zImage' file instead of 'ROMIMAGE' file.
Please refer
http://more.sbc.co.jp/slj/download/readme/readme_romimage112.asp

6. Enable the IPv6 code

If you have embedded the IPv6 protocol stack to the kernel, you are
ready. You can see 'inet6 addr' lines with ifconfig command.
If you have built as a module, you should copy the module and load it.
Copy the linux/net/ipv6/ipv6.o to CompactFlash card, and copy it to
the Zaurus's built-in ROM.
	# mkdir -p /lib/modules/2.4.6-rmk1-np2-embedix/kernel/net/ipv6/
	# cp /mnt/cf/ipv6.o /lib/modules/2.4.6-rmk1-np2-embedix/kernel/net/ipv6/
	# depmod -a
	# modprobe ipv6


Documented by Shinji Kobayashi