Thanks for all the replies. After reading all the helpful response. I think I will try to use initrd, and probably try ramdisk, too. I don't necessary need to run with a minimum system. The hardware has 8M, and I will try 1M for ramdisk. It seems like this is the easiest way to get thing starts.
--- Jerry Van Baren <vanbaren_gerald at si.com> wrote: > > You need at least a RAM file system for "/" and a > bunch of subdirectories > such as /dev, /lib, etc. The common way to do this > on a minimalistic > system is to create a file system image in ROM > (often compressed) and copy > it to RAM on start up. Given the questions you are > asking, I am very > confident creating a minimal RAM disk image will > challenge you sufficiently > :-). I'm not being snide, lots of people with lots > of linux knowledge have > tried and failed. Most people use someone else's > pre-configured minimal > file systems and add/subtract (mostly add :-) > programs to it. This is > because it is very, very hard to create a minimal > file system (that works, > that is). > > Pointers to development systems with example RAM > disk images: > http://www.denx.de/solutions-en.html > ftp://ftp.denx.de/pub/LinuxPPC/usr/src/SELF/ > http://www.mvista.com/ > (there are others, I'm just too lazy to do the > google search for you) > > Trying to run linux without a file system of any > sort would require you to > rewrite of pretty much everything and the three or > four things you didn't > rewrite, you would have to rebuild (static link, no > shared > libraries). There are a lot of software engineers > and hackers that would > turn down the opportunity to do this at any price. > On the other hand, a > lot of naivety and a even more coffee sometimes > generates remarkable > results :-). > > You really want to look at eCOS or one of the other > light weight tasking OSs. > http://www.redhat.com/embedded/technologies/ecos/ > > gvb > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/