player/Project/Src/MyApp/c_asm.c

#include "stm32f4xx.h"




void *get_r9(void) {
    void *r0;
    __asm volatile (
        "MOV %0, r9" : "=r" (r0)
    );
    return r0;
}

void set_r9(void *r9) {
    __asm volatile (
        "MOV r9, %0" : : "r" (r9)
    );
}