Re: ARM Simulator Bug?

["David Mc Kenna" <mckennad@esatclear.ie>]

Hi Richard,

>Try using an 
>
>	LDR r0, =__thumb
>

This command places the correct value into R0 for the BX command, but the bug
within the simulator is still present. 

Take the following code as an example.

0000005c <TST_start>:
  5c:   e3a0da12        mov     sp, #73728      ; 0x12000
  60:   e59f00a4        ldr     r0, [pc, #164]  ; 10c <IRQ_Interrupt+0x50>
  64:   e12fff10        bx      r0

00000068 <__start_of_thumb>:

void    IRQ_Interrupt(void);

int main()
{
  68:   b580            push    {r7, lr}
  6a:   466f            mov     r7, sp
  6c:   b082            sub     sp, #8

If I place a breakpoint at 0x6c and run the code gdb loses itself, i.e. if I
interrupt it with ctrl-c it says the PC is 0x0580fa70 or some thing similar.
Again, if I place a breakpoint at 0x5c, I can single step successfully. If I
single step to 0x68 and place a breakpoint at 0x6c and continue, gdb loses itself
again.

This problem only occurs when I attempt to use thumb. If I remove the bx command
and compile my C file in ARM mode the simulator works perfectly.

Is it possible to see which commands the simulator is executing? 

Thanks,
Dave


--
http://www.iol.ie