Re: linux kernel without file system

John Stoffel
2009-01-14T17:03:10Z

>>>>> "Philippe" == Philippe De Muyter <phdm@macqel.be> writes:

Philippe> On Wed, Jan 14, 2009 at 09:46:48AM +0100, Tomasz Chmielewski wrote:
>>> I need to design a very small embedded system that must only control
>>> one ethernet port and two serial lines and must fit in a very small flash
>>> memory. So I thought about replacing the call to /etc/init by my
>>> application
>>> program and removing all the file-system part of linux.
>>> Is that doable ?
>>> Is there a 'standard' way of doing that ?
>>> The first problem I see is accessing my serial lines. How could I do that
>>> without using open("/dev/ttySx"), which requires a file system ?
>>> Is there a way to access devices that does not require a file-system ?
>>
>> You could put everything in initramfs (and embed it in the kernel).

Philippe> Actually, I was thinking about reducing the footprint of my
Philippe> kernel by removing all the fs-related system calls, so the
Philippe> problem is not where the file-system is, but how to access
Philippe> (serial) devices without giving their "/dev/..." name.

Does it have to be linux? I've been playing with Arduino boards
(http://www.adafruit.com) lately and they have ethernet modules,
serial libraries, etc. All on a small small chip. Well, the ethernet
is a daughter board, but they're still pretty small.

Depends on how general purpose you need to make this device and what
you're trying to accomplish. Maybe you need to give people a better
idea of what you're trying to do, instead of assuming you need Linux
and trying to shoe-horn it into a really tiny space.

Cheers,
John