zephyr/arch/xtensa/core/include/xtensa_backtrace.h

97 lines
2.9 KiB
C

/*
* Copyright (c) 2020 Espressif Systems (Shanghai) Co., Ltd.
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#ifdef __cplusplus
extern "C" {
#endif
#ifndef __ASSEMBLER__
#include <stdbool.h>
#include <stdint.h>
/*
* @brief Structure used for backtracing
*
* This structure stores the backtrace information of a particular stack frame
* (i.e. the PC and SP). This structure is used iteratively with the
* z_xtensa_cpu_get_next_backtrace_frame() function to traverse each frame
* within a single stack. The next_pc represents the PC of the current
* frame's caller, thus a next_pc of 0 indicates that the current frame
* is the last frame on the stack.
*
* @note Call esp_backtrace_get_start() to obtain initialization values for
* this structure
*/
struct z_xtensa_backtrace_frame_t {
uint32_t pc; /* PC of the current frame */
uint32_t sp; /* SP of the current frame */
uint32_t next_pc; /* PC of the current frame's caller */
};
/**
* Get the first frame of the current stack's backtrace
*
* Given the following function call flow
* (B -> A -> X -> esp_backtrace_get_start),
* this function will do the following.
* - Flush CPU registers and window frames onto the current stack
* - Return PC and SP of function A (i.e. start of the stack's backtrace)
* - Return PC of function B (i.e. next_pc)
*
* @note This function is implemented in assembly
*
* @param[out] pc PC of the first frame in the backtrace
* @param[out] sp SP of the first frame in the backtrace
* @param[out] next_pc PC of the first frame's caller
* @param[in] interrupted_stack Pointer to interrupted stack
*/
void z_xtensa_backtrace_get_start(uint32_t *pc,
uint32_t *sp,
uint32_t *next_pc,
int *interrupted_stack);
/**
* Get the next frame on a stack for backtracing
*
* Given a stack frame(i), this function will obtain the next
* stack frame(i-1) on the same call stack (i.e. the caller of frame(i)).
* This function is meant to be called iteratively when doing a backtrace.
*
* Entry Conditions: Frame structure containing valid SP and next_pc
* Exit Conditions:
* - Frame structure updated with SP and PC of frame(i-1).
* next_pc now points to frame(i-2).
* - If a next_pc of 0 is returned, it indicates that frame(i-1)
* is last frame on the stack
*
* @param[inout] frame Pointer to frame structure
*
* @return
* - True if the SP and PC of the next frame(i-1) are sane
* - False otherwise
*/
bool z_xtensa_backtrace_get_next_frame(struct z_xtensa_backtrace_frame_t *frame);
/**
* @brief Print the backtrace of the current stack
*
* @param depth The maximum number of stack frames to print (should be > 0)
* @param interrupted_stack Pointer to interrupted stack
*
* @return
* - 0 Backtrace successfully printed to completion or to depth limit
* - -1 Backtrace is corrupted
*/
int z_xtensa_backtrace_print(int depth, int *interrupted_stack);
#endif
#ifdef __cplusplus
}
#endif