5 sec boot

[Deepak Saxena]

On Oct 04 2008, at 19:24, Deepak Saxena was caught saying:
> On Oct 04 2008, at 15:49, Mitch Bradley was caught saying:
> > c) Raw FLASH read time maxes out at 20 MB/sec.  But you don't get that  
> > speed from the filesystem; JFFS2 is good for between 5 and 10 MB/sec.
> >
> > Considering all the intricacies of JFFS2, my best guess is that it's  
> > going to be close to a wash whether the kernel + initrd is stored in  
> > compressed or uncompressed form.
> >
> > OTOH, if the kernel + initrd were in a separate partition in e.g. romfs  
> > format, where OFW could just blast them into memory without doing JFFS2  
> > node processing, we could probably get close to the 20 MB/sec speed.
> 
> We can probably just get away with making all of /boot into a
> romfs; however, do we even need to bother with a filesystem 
> representation of the images?  We could have four partions 
> (kernel0, kernel1, initrd0, initrd1) that contain the binary 
						s/binary/raw/
> data for current and alternate images and some sort of way
> to tell which one is current and which one is alternate.
> 
> ~Deepak
> 
> -- 
> Deepak Saxena - Kernel Developer - dsaxena at laptop.org

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