HP iPAQ 21x - How To Install

There are three ways of loading the linux kernel on the iPAQ 21x:

Booting linux directly from MMC card.
Switching to linux from windows CE.
Booting from flash.

The first method is easier, safer, more reliable and definately recommended. However, some MMC/SD cards (eg high capacity) cannot be read by the iPAQ bootloader. Please try the first method first but if it fails you will have to use the second method.

Once the kernel has booted it will try to use the 2nd parition on the MMC/SD Card's as its root filesystem. The following must be done for BOTH booting methods:

Create at least 2 paritions on an MMC/SD card.
Make an ext2 filesystem on the second parition.
Download the latest Angstrom distribution tarball (angstrom-hpipaq214-xxx.tar.gz) and untar into the partition. It's best to do this as root and with the flag 'p' included in the tar command in order to preserve permissions, symbolic links and things.
Download angstrom-ipaq214-additional.tar.gz and untar into the partition.

Booting from MMC Card

To boot from the MMC Card:

Create a FAT16 parition as the first partition on the MMC card.
Make it active (bootable)
Download the latest U-Boot image (u-boot-ipaq214-xxx.bin), save it to the card and rename it to 'BLDIAG.NB0'.
Download the latest kernel image (uImage-ipaq214-20090322.bin) and save it to the card as 'uImage-ipaq214.bin'
Hold down the left two buttons (Calender and the Windows key)
Press reset.
U-Boot should appear and you can boot from the MMC card with option 1.

Booting from HaRET

To boot from HaRET.

1) Download HaRET. To just boot linux you can use the official one from http://www.handhelds.org/moin/moin.cgi/HaRET or, if you intend to do any developing/reverse engineering, get my version from the downloads page.
2) Download the latest U-Boot image (u-boot-ipaq214-xxxx.bin).
3) Download default.txt.
4) Edit default.txt and edit the reference to u-boot-ipaq214-xxxx.bin to the U-Boot file you downloaded.
5) Place the haret.exe, default.txt and u-boot-ipaq214-xxxx.bin all in the same folder in winCE somewhere.
6) Download the latest kernel image (uImage-ipaq214-20090322.bin) and save it to the FAT16 partition on the card as 'uImage-ipaq214.bin'
7) Turn off the Wifi and Bluetooth. Unplug the DC Power and remove any USB devices/leads from the iPAQ.
8) Remove the battery and wait ~10secs.
9) Replace the battery and let the iPAQ boot into windows.
10) If for some reason the Wifi/Bluetooth have come on, switch them off.
12) Run haret.exe.
13) Click 'run'
14) U-Boot should appear and you can boot from the MMC card with option 1.

Booting from HaRET starts linux with all the hardware in whatever unpredictable state winCE left it in. This usually causes problems of various sorts including that the USB Host system will not work at all. Steps 7-10 in the above instructions are included to minimise this so they may not be absolutely necessary.

Booting from flash

This seems to work OK now. The details are on the flash page.