NanoX was Re: RTEMS Shell

[Joel Sherrill]

Rosimildo.. please provide advice on NanoX and GUIs.

amimjf at connectfree.co.uk wrote:
> 
> >Dear ppl,
> >
> >I'm still trying to understand how RTEMS works.. I've downloaded the
> >4.5.0 and compiled it fine.. After compilation, I get a bunch of files
> >in the build/BSP/samples directory. I'm built it for the LEON.. and I
> >tested the software with TSIM..
> >
> >Now it occurs to me, that there seems to be lack of a shell.. The files
> >run fine.. Even the multi-thread sample runs fine.. So, this tells me
> >that the OS is working.. Just one problem.. there's no shell..
> >
> >Is there a shell for the RTEMS??
> 
> do you mean a unix/linux type bash/csh/sh shell ? or a GUI shell ?
> 
> rtems is an embedded operating system its not like unix where you use the shell to copy files around, edit them for configureation, etc. So there is no real need for a 'shell' as such.
> 
> Of course people have created / ported shells to rtems one of them is even quite small, i think its called 'busybox' or 'blackbox' or somehting like that, i cant remeber exactly.

The "shell" included with RTEMS is a mini-POSIX-ish shell that is very
basic.
Deeply embedded systems just don't usually require that type of
interaction.
But there is a telnetd that allows remote access to that shell and even
login support. :)

RTEMS is generally a statically linked environment in which your 
system is more akin to a single UNIX executable.  There is work on 
dynamically loading application pieces but that does not change 
the overall structure.  RTEMS is logically a single process,
multi-thread environment.

[NOTE: There is a notion of a psuedo-process which allows a 
group of threads to have their own copy of data which UNIX
would consider "process data" but there is no memory protection
at all.]

> >What kind of filesystem does the RTEMS use??
> 
> any you want, (or can port accross), its does have a flash filesystem and a ram filesystem.

And a TFTP filesystem and now a FAT12/16/32 filesystem.  

> >What's the filesystem organization??
> 
> well, as i said rtems isent unix (RNU !), its does not store parts of itself in files, the device access and other stuff is based around unix (/dev etc)

Right.  Code that has been ported from UNIX/POSIX to RTEMS has
expectations of 
filesystem existence and placement (e.g. /etc/passwd and /etc/hosts). 
Chris
Johns provided a utility to generate the network stack related files
from
RTEMS configuration information so porting other net utilities is
easier.

> >Can RTEMS support rom filesystem??
> 
> yes,.
> 
> >I plan to put in NanoX in the future.. How should I go about placing it
> >in and starting it up? (that's why I asked about the rom filesystem).

The usual trick is to include a tar of the initial filesystem somehow
in the program image and sue that to populate the RAM filesystem.

Rosimildo.. do you have any advice on NanoX/MicroWindows?


> >Just some questions..
> >
> >With Metta,
> >Shawn Tan.
> >
> 
> ---
> Matthew J Fletcher
> amimjf at connectfree.co.uk
> ---

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985