Joel Sherrill joel.sherrill at
Fri Feb 1 12:12:20 UTC 2002

jtm at wrote:
> I'm considering RTEMS for an ARM based board and was wondering how
> complete the ARM support is. I know I'll have to do a BSP, but
> what about basic ARM support? I see a BSP based on the ARM7TDMI;
> will that work on an ARM9 based design without a lot of modifications?

>From RTEMS perspective, the question is what differs between ARM9
and ARM7 for the instruction and register sets.  This is primarily 
what is managed in score/cpu/arm.  Issues like varying on-CPU
interrupt management and cache are addressed in libcpu/arm.

But I don't know offhand what's different at each ARM ISA level
so can't give details.  It is usually only a matter of knowing
what differs and addressing that.  On other CPU families, we expect
very specific and mostly minor differences.

> Also, what tool configuration should be used to build the arm_bare_bsp
> target? arm-rtems? arm-rtemself?

You should use arm-rtems.  If you are on Linux, just grab prebuilt
If on Cygwin, I posted some tools last week on the ftp site built using
new script I wanted feedback on.  Either way, you don't have to build
them. :)

The 2nd question is the BSP.  What board are you using?  You will 
almost certainly have to create a new BSP for it to support its
hardware.  It is likely that libchip and other BSPs will have 
stuff to help you though.

> Thanks.
> --
> Jay Monkman         The truth knocks on the door and you say "Go away, I'm
> monkman at    looking for the truth," and so it goes away. Puzzling.
>                      - from _Zen_and_the_Art_of_Motorcycle_Maintenance_

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

More information about the users mailing list