I am puzzled about the addresses that are used in many of the commands. I am obviously aware that they are hex numbers, related to the addresses of things, but I can't seem to find any explanation of how the nand and ram are laid out and why particular addresses are chosen.
For instance - the factory boot sequence defines the bootcmd environment
bootcmd=nand read.e 0x800000 0x100000 0x400000 ; bootm 0x800000
help for nand read.e says 0x800000 is an addr and there is one other parameter (off | partition size). I can't find any more documentation that refers to this, yet this command has 3 parameters.
I assume the kernel is being loaded into RAM at 8MB and then the bootm command starts it executing from there. WHY 8MB? The Debian instructions (
http://www.cyrius.com/debian/kirkwood/sheevaplug/install.html) loads it into 4MB and puts an Initrd Image at 8MB. Why the difference. Are these numbers plucked out of thin air, or is there a reason they are like they are?