On Tue, May 09, 2006 at 03:52:20PM -0700, Howard, Marc wrote: > > > > In message <20060509171520.GA10886 at gate.ebshome.net> you wrote: > > > > > > After many years of doing embedded Linux stuff I still don't > > > understand why people are so fond of initrd. > > > > > > For temporary stuff - tempfs is much better and flexible. For r/o > > > stuff - just make separate MTD partition (cramfs, squashfs) > > and mount > > > it directly as root. Both options will waste significantly less > > > memory. > > > > Agreed. > > > > And if somebody wants to see facts and numbers, please see > > http://www.denx.de/wiki/view/DULG/RootFileSystemSelection > > > > One size does not fit all. We have an application with a very large > file system. It can't fit in the available flash, however we do have a > ton of RAM (512MB). NFS is not an option nor is it desirable (latency > and availability issues). Boot time is not an issue either in this case > as it takes the equipment many minutes to calibrate and initialize. > > initrd also solves another problem. The combined uBoot multi-image > although huge (>32 MB) represents a complete system firmware snapshot in > a single (huge) file. By selecting the appropriate uImage the host can > guarantee the linux build, device drivers, application version and FPGA > firmware revs (the embedded board is rebooted to guarantee a repeatable > starting state). This makes revision control for the overall system > much easier, especially since the host system is running windoze.
This all is nice provided you use network for boot. IMHO this is quite _rare_ setup (especially Windows host!!!). For 99% of embedded designs this is obviously not a viable option. -- Eugene