On Aug 5, 2008, at 9:33 PM, Jerry Van Baren wrote:
Kumar Gala wrote:
here's a rough start at an outline for the bootm script based on the code (I've only outlined the Linux/PPC boot case its seems the most complicated). One of the first things we clearly need is a imload command. Thoughts on the various disable_{interrupts, usb, caches} ?
- k
Another rough start on an outline (only cmd_bootm.c, need to add image.c information): http://www.denx.de/wiki/view/U-Boot/UBootFdtInfo#Refactoring_bootm
Goal is to identify the major pieces of the sequence, identify what commands we have and what we need to make a scripted equivalent sequence for (ultimately) each path through the sequence.
I added a few bullets about functionality I'd like to see the new sequence to be capable of it.
one idea is having "stages" of bootm handled as sub commands:
bootm start <args> bootm prep (disable interrupts, stop usb, disable caches) bootm load_os (decompress OS image) bootm load_fdt(relocates fdt to proper place, setup bootargs, initrd prep, board setup?? [or do via fdt boardsetup command]) bootm load_initrd bootm jump
bootm restore (undo anything prep did, reset state tracking)
And we keep state around so the next stage can run w/o a lot of arguments and you have to execute these in order, and only once. But you can intermix other commands between the stages.
We could also have some "bootm query <foo>" to expose the internal state if that's useful. We could completely get rid of the various "env" vars that impact bootm and just make them state variables ("verify", "autostart", "bootm_size", "bootm_low", ...)
Also, bootm would be the sequence of: bootm start <args> bootm prep bootm load_os bootm load_fdt bootm load_initrd bootm jump
comments?
- k