esp-idf/components/xtensa/debug_helpers_asm.S

58 wiersze
2.2 KiB
ArmAsm

// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <xtensa/coreasm.h>
#include <xtensa/corebits.h>
#include <xtensa/config/system.h>
#include <xtensa/hal.h>
/*
* esp_backtrace_get_start(uint32_t *pc, uint32_t *sp, uint32_t *next_pc)
*
* High Addr
* ..................
* | i-3 BS |
* | i-1 locals | Function B
* .................. i-1 SP
* | i-2 BS |
* | i locals | Function A (Start of backtrace)
* ------------------ i SP
* | i-1 BS |
* | i+1 locals | Backtracing function (e.g. esp_backtrace_print())
* ------------------ i+1 SP
* | i BS |
* | i+2 locals | esp_backtrace_get_start() <- This function
* ------------------ i+2 SP
* | i+1 BS |
* | i+3 locals | xthal_window_spill()
* ------------------ i+3 SP
* .................. Low Addr
*/
.section .iram1, "ax"
.align 4
.global esp_backtrace_get_start
.type esp_backtrace_get_start, @function
esp_backtrace_get_start:
entry a1, 32
call8 xthal_window_spill //Spill registers onto stack (excluding this function)
//a2, a3, a4 should be out arguments for i SP, i PC, i-1 PC respectively. Use a5 and a6 as scratch
l32e a5, sp, -16 //Get i PC, which is ret addres of i+1
s32i a5, a2, 0 //Store i PC to arg *pc
l32e a6, sp, -12 //Get i+1 SP. Used to access i BS
l32e a5, a6, -12 //Get i SP
s32i a5, a3, 0 //Store i SP to arg *sp
l32e a5, a6, -16 //Get i-1 PC, which is ret address of i
s32i a5, a4, 0 //Store i-1 PC to arg *next_pc
retw