Setting ARM CPSR to C variable

Im using the TI Code Composer suite with an ARM 7 and Im looking for a way
to get the CPSR back into a C variable. I was looking through the
documentation that came with the compiler and it didnt have quite what I
was looking for. What Im need to do is get the state of the interrupt
disable bit. I need to use this bit as a condition variable for something
like:

===

if (interrupts enabled){
  do this 
}

===

the inline asm syntax is just 

===
asm("assembly");
===

The problem is, Im not sure how to associate some C variable to the asm
code to pass the CPSR back to the C code flow.  Ive used other compilers in
the past that have an option to pass arguments to the asm code like 

===
_asm("tfr b, ccr",foo);
===


which passes the condition code register (for an HC12) to the var foo, but
this compiler does not have that capability.  

I first tried

===

  volatile ui32_t cpsrstat;
   
  asm("     .global _cpsrstat");       // cpsrstat defined in C code
  asm("_cpsrstat .set r0");            // set variable to r0
  asm("	  mrs r0,cpsr");               // move CPSR to r0

===

With this Im getting an illegal mnemonic error at the MRS instruction.  Am
I barking up the wrong tree here?
	

Luken8r wrote:
> Im using the TI Code Composer suite with an ARM 7 and Im looking for
> a way to get the CPSR back into a C variable.

This is how you do it in GCC just in case it helps.  I didn't write it, but 
I can confirm that it does work.

static inline unsigned asm_get_cpsr(void)
{
  unsigned long retval;
  asm volatile (" mrs  %0, cpsr" : "=r" (retval) : /* no inputs */  );
  return retval;
}

Anthony Fremont wrote:
> Luken8r wrote:
>> Im using the TI Code Composer suite with an ARM 7 and Im looking for
>> a way to get the CPSR back into a C variable.
>
> This is how you do it in GCC just in case it helps.  I didn't write
> it, but I can confirm that it does work.
>
> static inline unsigned asm_get_cpsr(void)
> {
>  unsigned long retval;
>  asm volatile (" mrs  %0, cpsr" : "=r" (retval) : /* no inputs */  );
>  return retval;
> }

I did not get to see if this compiles, but this should work.

static inline unsigned asm_get_cpsr(void)
{
     unsigned long retval;
     __asm (" mrs  r0, cpsr" );
     __asm (" mrs  retval, r0" );
     return retval;
}

or slightly shorter, directly in an asm function in a C module:

asm_get_cpsr: .asmfunc
    mrs    r0,cpsr        ; get cpsr
    mov    pc, lr        ; return to caller
 .endasmfunc

Scott