[maemo-developers] [maemo-developers] Re: [maemo-announce] New Nokia 770 software image available

[From: Frantisek Dufka]

Michael Wiktowy wrote:

> That is also something that could be said for the flashing through the
> USB method too. If that is interrupted then you are likely equally
> unable to boot your 770. However, you can always try again ...

There is big difference. You don't need the device to be bootable for 
USB flashing. You need it to be bootable for this new method for 
flashing from itself. So why to invest time (being Nokia) to develop 
second way of flashing if it cannot replace first one and is not 
failproof at all?

Having said that, everything except bootloader and config partition_can_ 
be reflashed from the device (see my kernel and initfs flasher 
http://fanoush.webpark.cz/maemo/ ) and rootfs could be easily reflashed 
while booted from MMC as well.

> What might really complicate this a great deal is if the N770 kernel
> uses those "run in place" features I recall reading about that was
> introduced for embedded systems that causes the kernel to just run
> apps directly from flash memory rather than copying them to RAM and
> then running from there. Writing directly to a program space that you
> are currently running is the road to nastiness.

Well it is not so bad due to way NAND works but in fact initfs is in 
similar situation. dsme daemon runs from initfs partition and cannot be 
stopped easily so it is not completely clean to reflash initfs while it 
is running. It seems to work but is a kind of hack. Kernel is OK it is 
decompressed to RAM on boot.

Frantisek