Hi all,

I started to port freeRTOS to an ARM7-based TMS470R1B1M but now I'am facing some problems.
At the beginning I thought that it is no big deal as there are already some ARM7 ports available.

So I took the ARM7_AT91SAM7S port as example.
At the beginning I modified the timer initialization and the timer ISR and
both worked.

I did not modify the macros portRESTORE_CONTEXT
and portSAVE_CONTEXT as the assembler instructions should be the same.
But unfortunately, it does not work. After the following commands in
RESTORE_CONTEXT, the PC register points to somewhere.

LDMFDLR, {R0-R14}^
NOP
LDRLR, [LR, #+60]
SUBSPC, LR, #4

Is there anybody who is working on a TMS470 port too or can someone point me to some hints?

I use gnu-arm-gcc 4.0.2, arm mode only and I started without using preemption.

TIA
Torsten

Well, after some modifications the context switch works.
I'll let you know, when I'm ready with the complete port.

Torsten

I have a tms470 port that was sent to me recently, I'm not sure if it is complete yet and don't have the means (yet) to test it. I would be grateful for your port also when it is complete so it can become a supported processor ;-)


I'm surprised you had to change the macro definitions. Did you start with a GCC port as your base, or the IAR SAM7 port?

The GCC ports can use inline assembler __attribute__((naked)) to keep all the code in the C files, whereas the IAR ports use a slightly different technique.

Also, did you call the first portRESTORE_CONTEXT from supervisor mode? This is essentail, and the easiest way to do it is by switching the supervisor mode prior to calling main().

Regards.

>I'm surprised you had to change the macro
>definitions. Did you start with a GCC port as
>your base, or the IAR SAM7 port?
I'm also surprised. So maybe something different is wrong to with my port.

So could you send me the TMS470 port you got recently? It would be a great help for me.

Regards
Torsten

I can send it when I get back from my business trip.

What was it you had to change?

Regards.

Do you think about publishing the TMS470 port ?
I'am a newbee with FreeRTOS and TMS470... and i would like to use it on the Olimex TMS470-P256 prototype board.

Hello there

I'm trying to port FreeRTOS to TMS470.

I've 2 tasks
- an LCD driver waiting for an LCDMessage
- another task trying to send a message when it starts.

The second task starts to work and queues a message to the first one. But when calling taskEXIT_CRITICAL() inside xQueueSend() function my software goes I don't known where ?

I suppose that there is something wrong with task switching and/or interrupts...

Can someone help me ?