Thread: Booting from MMC on N800 Now Available!!
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freeman is offline freeman
2007-02-05 , 18:38
Posts: 152 | Thanked: 6 times | Joined on Dec 2006
#40
Originally Posted by fanoush View Post
No, in current system you need to flash at least initfs and kernel to boot newer firmware completely. Newer kernel and initfs may (or may not, depends on specific version) make older rootfs in flash not booting. Not talking about flashing bootloader of course which is sometimes updated too and currently cannot be flashed from device.

What may be possible is to replace kernel and initfs in flash with some generic stubs and keep real kernel and initfs on mmc so we can have more of them. This is quite tricky but maybe possible. Maybe it would be even needed to dualboot between os2007 hacker edition and IT2006 so I will be forced to try to make it working :-)
And when you say in current system, you meant both the 770 and N800 and the way they were design for now right. Cuz, when I upgrade the kernel on my N800, the only way I could upload the kernel is to use 'flasher-3.0 -k'.
The way I see it right now is that the flash have 5 sections, aka 5 partition.
blk0=128KB
blk1=385KB
blk2=2MB
blk3=2MB
blk4=the rest=rootfs

For obvious reason, It's safe to assume that blk0 is a loader and blk4 is the rootfs
blk3 seem to be initfs in the jffs2 format.
so, blk2 is the only one left large enought to fit the kernel. (I don't think nokia want to store kernel on a compressed partition) and therefore mean, if you make your own kernel, it has to be less than 2MB(there may be some overhead there as well.) blk1 then probably a special kernel used for usb flasher. and that mean leave those 2 alone(block0 and 1) if you don't want your $400 toy to be an expensive paperweight.