1/* 2 * Copyright 2018, Data61 3 * Commonwealth Scientific and Industrial Research Organisation (CSIRO) 4 * ABN 41 687 119 230. 5 * 6 * This software may be distributed and modified according to the terms of 7 * the BSD 2-Clause license. Note that NO WARRANTY is provided. 8 * See "LICENSE_BSD2.txt" for details. 9 * 10 * @TAG(DATA61_BSD) 11 */ 12#include <autoconf.h> 13#include <utils/gen_config.h> 14#include <utils/stack.h> 15 16void * 17utils_run_on_stack(void *stack_top, void * (*func)(void *arg), void *arg) 18{ 19 void *ret; 20 asm volatile ( 21 "mv s0, sp\n\t" /* Save sp - s0 is callee saved so we don't need to save it. */ 22 "mv sp, %[new_stack]\n\t" /* Switch to new stack. */ 23 "mv a0, %[arg]\n\t" /* Setup argument to func. */ 24 "jalr %[func]\n\t" 25 "mv sp, s0\n\t" 26 "mv %[ret], a0\n\t" 27 : [ret] "=r" (ret) 28 : [new_stack] "r" (stack_top), 29 [func] "r" (func), 30 [arg] "r" (arg) 31 /* caller saved registers */ 32 : "t0", "t1", "t2", "t3", "t4", "t5", "t6", "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "ra"); 33 return ret; 34} 35