$AQVm5 writes:
> Hi
>
> I am build vxWorks for ARM 920t, using gcc 3.4.4 which I think is
> slightly modified by WindRiver, it accepts the -t5 and -t4 options
> which I don't find in the gcc user manual. Code generation with -t5
> option and without -t5 option is different. here is my test code:
>
> void AT91USIntRx(AT91_US_CHAN *pChan)
> {
> char inChar;
> inChar = pChan->regs->dbgu_rhr;
> inChar = dbgu->dbgu_rhr;
> putc(inChar);
> (*pChan->putRcvChar)(pChan->putRcvArg, inChar);
> }
>
> objdump results( complied with -t5 option):
>
> (*pChan->putRcvChar)(pChan->putRcvArg, inChar);
>
> 20005ca0: e51b3010 ldr r3, [fp, #-16]
> 20005ca4: e51b2010 ldr r2, [fp, #-16]
> 20005ca8: e55b1011 ldrb r1, [fp, #-17]
> 20005cac: e5933008 ldr r3, [r3, #8]
> 20005cb0: e5920010 ldr r0, [r2, #16]
> 20005cb4: e12fff33 blx r3
>
>
> when executing the blx instruction, the application is out of control!
That must be because there is a bad address in r3. What is the value
of r3 at this point? It's quite ok to use BLX in ARM code.
Andrew.
