Hi im trying to call a assembler subroutine from c and get this error. On the Arm websites, there is just stated that this error exists.. C Code

    #include <stdint.h>
extern void out_word(uint32_t out_address, uint32_t out_value);
extern uint32_t in_word(uint32_t in_address);
int main(void){
        uint32_t value = in_word(0x60000200);
        uint32_t address = 0x60000100;
        out_word(address,value);
    return (0);
}

Assembler Code

                PRESERVE8
                AREA myCode, CODE, READONLY
                EXPORT in_word
                EXPORT out_word

in_word         PUSH {R1-R7}
                LDR R1, R0 ; line which produces the problem
                LDR R0, [R1]
                POP {R1-R7}
                BX LR
                
                
out_word        STR R1, [R0]
                BX LR
                   
                END

FINAL SOLUTION WHICH WORKS

                PRESERVE8
                AREA myCode, CODE, READONLY
                EXPORT in_word
                EXPORT out_word

in_word         LDR R0, [R0]
                BX LR
                
                
out_word        STR R1, [R0]
                BX LR
                   
                END

CodePudding user response：

You use the wrong instruction. LDR - Load with immediate offset, pre-indexed immediate offset, or post-indexed immediate offset

You need to use mov instruction