I like to understand how things work, so might update uBoot manually. Is there a good concise guide on how to do this?.
I also seem to recall reading the non marvel kernels don't have power management. Is this true? As thats pretty big omission and a reason why I might pass on updating.
there are two ways to upgrade uboot. Either directly write to nand using jtag (you need this to recover from a bad uboot upgrade) or boot into uboot and then tftp the new binary.
Writing to nand using jtag is covered in the alpha installer. I haven't investigated how to prepare a fitting binary.
Compiling your own uboot and writing it using tftp goes like this.
to compile your uboot (based on uboot 1.1.4 + marvel patches + sd-card patches) follow thread http://plugcomputer.org/plugforum/index.php?topic=183.0
or search the thread there is a ready compiled binary attached.
to write using tftp
* setup tftp server in your network. place uboot.bin in tftp root folder.
* boot plug to uboot (hit key to prevent autoboot)
* set plug ip (setenv ipaddr 192.168.1.10) and tftp ip (setenv serverip 192.168.1.2)
* flash image from tftp (bubt u-boot.bin)
* reset plug (reset)
It looks like the cpuidle patch made it into mainline linux 2.6.31-rc4, no idea if it is already in earlier releases