The prototype of a Ccallable assembly function in a C progra

The prototype of a C-callable assembly function in a C program is extern int norm_sq_asm (int * p, in/n): Based on the rule of the ARM Architecture Call Standard, find which core registers are used to pass the pointer p and the integer n to the assembly function and which register used for return value of the assembly function.

Solution

low register r1 is used to pass integer value n.

stack pointer r13 is used to pass pointer *p.

link register (LR) is used for return value.