5 sec boot

[Deepak Saxena]

On Oct 03 2008, at 07:34, Mitch Bradley was caught saying:
> >
> > Could somebody explain me whether [the 5 second boot] results are applicable to the 
> > XO, and how far are we from it, please?
> >
> >   
> 
> Ticket http://dev.laptop.org/ticket/4349 details my and codyl's 
> experiments with speeding up boot.

Some other ideas:

- Right now the firmware copies the uncompressed kernel and initrd 
  to memory and then the kernel and initrd decompressor has to re-read
  it from memory and write it back out in decompressed format. If 
  it is stored deocompressed to begin with on the filesystem, we 
  can simply read it into mem from flash and run. This would require
  a few extra MiB of flash. Granted, reading from flash is 
  slower than reading from memory, so we may not see a a net
  benefit.  Easy enough to test...

- Embedded systems often use a suspend image to speedup boottime. 
  Basically load an image into memory and then jump into the
  kernel as if we are resuming from firmware. Another approach
  if we can't do a full suspend image this is to use the new 
  container code and save the runtime of the user session so we
  can just reload it. Both these methods require flash space...

~Deepak

-- 
Deepak Saxena - Kernel Developer - dsaxena at laptop.org