You don't have to have disk to use filesystem.
Lot of people using CompactFlash to hold filesystem.
There is also the NFS option.
> -----Original Message-----
> From: Justin Carlson [mailto:firstname.lastname@example.org]
> Sent: Tuesday, February 18, 2003 2:22 PM
> To: email@example.com
> Cc: firstname.lastname@example.org
> Subject: Re: Exec from Memory
> On Tue, 2003-02-18 at 17:08, Maurice Turcotte wrote:
> > Greetings:
> > I have a hypothetical linux-mips question posed by a colleage.
> > Suppose there is no file system available, since there is no disk. And
> > suppose that I had the capability to place an elf file in a known
> > in memory. How would I execute it? It seems like exec really wants a
> > name. BTW, this needs to run in use space, not kernel.
> There's no easy way (that know of) around the filesystem abstraction.
> You're going to have to deal with it in some manner. Really basic
> stuff, like the elf loader, depends on vfs abstractions. While it's
> possible to bypass all that, it would be a *lot* of work, and a lot of
> nearly-duplicated code.
> I can see a couple of options. Other people might have better
> suggestions. :)
> 1) Use the embedded root ramdisk functionality in the kernel. Make your
> elf file /sbin/init, and run with it.
> 2) Hack a quick filesystem that uses a contiguous chunk of memory that
> you either hardcode or pass in on the kernel command line.