On Sat, 8 Jan 2000 almesber@lrc.di.epfl.ch wrote:
> Alex Holden wrote:
> > The initial RAM disk tftp support is effectively a complete kernel-space
> > TFTP client implementation, configured to load the initial RAM disk with a
> > file (currently specified at compile time) obtained from a TFTP server.
> If all you want is another RAM disk, you could just put all the tools
> you need to download it on an initrd, then construct the RAM disk, and
> then mount that one as root. Unless you're really badly limited for
> space, this (i.e. a stripped-down user space tftp) should be a lot more
> convenient to maintain.
Maybe I explained badly what it does and what it's for. It's not for
systems which can load a RAM disk or initrd normally. It's for systems
which don't have the ability to load a ramdisk from a disk (because there
isn't one), but do have the ability to load and execute a block of code
(the kernel) from the network. This patch allows the kernel, once it's
determined it's IP address, to load a file (optionally gzipped) from a
tftp server and put it into /dev/ram0. You can then use it as an initrd
if you want, or if you want to use it as your root filesystem just use
root=/dev/ram on the command line (which is what I'm doing). It's intended
to be used as a simpler, more reliable, easier to configure and maintain,
alternative to mounting a remote filesystem using nfsroot and then copying
it into a RAM disk for embedded systems which boot from the network but
run completely from a RAM disk so they don't fall over whenever the
network does.
BTW, I ported it to 2.3 and improved it quite a bit. Now you can turn off
the boot loader initrd support and still have the initrd-tftp work, and it
also handles nicely the case where you have initrd-tftp compiled in, but
don't want to use it. I consider it to be pretty much complete now and
won't be putting any more work into it except for back porting the
improvements to 2.2 unless somebody finds a bug in it.
See:
ftp://ftp.linuxhacker.org/pub/kernel/initrd-tftp/initrd-tftp.0.9.patch.gz
That patch was against 2.3.36, but it should work fine with later kernels
too. I sent it to Linus just after he released 2.3.36, but he didn't reply
about whether he would consider including it or not.
--------------- Linux- the choice of a GNU generation. --------------
: Alex Holden (M1CJD)- Caver, Programmer, Land Rover nut, Radio Ham :
-------------------- http://www.linuxhacker.org/ --------------------
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This archive was generated by hypermail 2b29 : Sat Jan 15 2000 - 21:00:12 EST