Re: Re[2]: [Etherboot-developers] Q: device naming....

[Eric W B. <ebi...@ln...>]

Ronald G Minnich <rmi...@la...> writes:

> On Wednesday 21 August 2002 11:50, Eric W Biederman wrote:
> 
> > I didn't see the file system type in the naming systax (fat was required).
> > I saw etherX but I didn't see anything beyond that.
> 
> 
> I'll try to find a better example(s)
> 
> Although catching up on this thread it sounds like a file system driver is 
> not of interest? Just checking.

Yes, and no.

Ultimately a filesystem driver is useful.

There are two cases.

Have a simple consistent interface that everything supports that is
enough to boot from disk.  For a PCBIOS this is reading the first
sector from the drive and jumping to it.  With LinuxBIOS and Etherboot
I am aiming at being just slightly more sophisticated.

Once you can get something off of the drive, and you aren't limited by
what you can put into the ROM chip you can be a lot more flexible.

I am definitely convinced that filesystem drivers can be small and
useful.  I know Ollie Lho, and Ada Agnew have had pretty good luck
with them.  It certainly makes sense to have them someplace in the
bootloader path.  I'm just not certain if etherboot is the tool to
have them.  

So for the url case having a way to specify filesytems and partitions is
definitely good. 

I suspect just:
file:///<device>/<partition>/<path/to/file>
is good enough.  Because partition types and filesystem types can
be autodetected.

If etherboot were to have a filesystem drivers I suspect the way
to go is to configure it to have 2 modes of operation.  Full on
filesystem, and configuration file support, and simple stupid read an
ELF image from the ram disk device support.  With the simple version
going in ROM chips and the complicated coming off the filesystem, network,
and only occasionally being flashed into the ROM when there is room.

But space wise we are doing pretty good currently etherboot will every
driver is only 65K.

Eric