SVC Functions in RTX (Arm Compiler v6)

Thanks Ronan for your answer.

I've already read the documentation that you reported me, but I'd like to better understand the syntax meaning.

For example, in the example reported in the previous link (CMSIS_Dev):

// SVC Wrapper
__STATIC_FORCEINLINE uint32_t atomic_inc32 (uint32_t *mem) {
register uint32_t val;

__ASM volatile (
"svc 1" : "=l" (val) : "l" (mem) : "cc", "memory"
);
return (val);
}

// SVC Handler
uint32_t svc_atomic_inc32 (uint32_t *mem) {
  // A protected function to increment a counter. 
  uint32_t val;
   
  __disable_irq();
  val  = *mem;
  (*mem) = val + 1U;
  __enable_irq();
   
  return (val);
}

There is a SVC function handler with a pointer and a return value, so in the assambler wrapper include "l" and "cc" symbols, where can I find a documentation that will help me to understand the meaning of this sintax?

Thanks a lot,

Flavio

Thanks Ronan for sharing.

Hi Stuart,

The answer is the second one: "or do you just want to add new C routines to fire on e.g. SVC 1, SVC 2 calls".

I wanted to know the right syntax to write a SVC assembler wrapper starting from a C function. The page reported to me by Ronan is a good reference to understand better.