esp-idf/components/esp_system/port/include/riscv/libunwind-riscv.h
Omar Chebib eeaa40f71d System: implement libunwind library for RISC-V backtracing
Closes https://github.com/espressif/esp-idf/issues/7866

A minimal x86 implementation has also been added, it is used to perform a host test.
2023-05-15 11:19:03 +08:00

214 lines
8.4 KiB
C

/*
* SPDX-FileCopyrightText: 2020-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* This file describes the frame types for RISC-V, required for
* parsing `eh_frame` and `eh_frame_hdr`, and more generally libunwind.
*/
#pragma once
#include <stddef.h>
#include "esp_attr.h"
#include "riscv/rvruntime-frames.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Define the size of a CPU register.
*/
#define ARCH_WORD_SIZE (sizeof(long))
/**
* @brief Retrive the index of a field inside a structure. All the fields
* must have a word size.
*/
#define indexof(structure,field) (offsetof(structure, field) / ARCH_WORD_SIZE)
/**
* @brief Define the Executionframe as RvExcFrame for this implementation.
*/
typedef RvExcFrame ExecutionFrame;
/**
* @brief Enumeration of all the registers for RISC-V architecture
*/
typedef enum {
UNW_RISCV_PC = indexof(ExecutionFrame, mepc),
UNW_RISCV_RA = indexof(ExecutionFrame, ra),
UNW_RISCV_SP = indexof(ExecutionFrame, sp),
UNW_RISCV_GP = indexof(ExecutionFrame, gp),
UNW_RISCV_TP = indexof(ExecutionFrame, tp),
UNW_RISCV_T0 = indexof(ExecutionFrame, t0),
UNW_RISCV_T1 = indexof(ExecutionFrame, t1),
UNW_RISCV_T2 = indexof(ExecutionFrame, t2),
UNW_RISCV_S0 = indexof(ExecutionFrame, s0),
UNW_RISCV_S1 = indexof(ExecutionFrame, s1),
UNW_RISCV_A0 = indexof(ExecutionFrame, a0),
UNW_RISCV_A1 = indexof(ExecutionFrame, a1),
UNW_RISCV_A2 = indexof(ExecutionFrame, a2),
UNW_RISCV_A3 = indexof(ExecutionFrame, a3),
UNW_RISCV_A4 = indexof(ExecutionFrame, a4),
UNW_RISCV_A5 = indexof(ExecutionFrame, a5),
UNW_RISCV_A6 = indexof(ExecutionFrame, a6),
UNW_RISCV_A7 = indexof(ExecutionFrame, a7),
UNW_RISCV_S2 = indexof(ExecutionFrame, s2),
UNW_RISCV_S3 = indexof(ExecutionFrame, s3),
UNW_RISCV_S4 = indexof(ExecutionFrame, s4),
UNW_RISCV_S5 = indexof(ExecutionFrame, s5),
UNW_RISCV_S6 = indexof(ExecutionFrame, s6),
UNW_RISCV_S7 = indexof(ExecutionFrame, s7),
UNW_RISCV_S8 = indexof(ExecutionFrame, s8),
UNW_RISCV_S9 = indexof(ExecutionFrame, s9),
UNW_RISCV_S10 = indexof(ExecutionFrame, s10),
UNW_RISCV_S11 = indexof(ExecutionFrame, s11),
UNW_RISCV_T3 = indexof(ExecutionFrame, t3),
UNW_RISCV_T4 = indexof(ExecutionFrame, t4),
UNW_RISCV_T5 = indexof(ExecutionFrame, t5),
UNW_RISCV_T6 = indexof(ExecutionFrame, t6),
UNW_RISCV_MSTATUS = indexof(ExecutionFrame, mstatus),
UNW_RISCV_MTVEC = indexof(ExecutionFrame, mtvec),
UNW_RISCV_MCAUSE = indexof(ExecutionFrame, mcause),
UNW_RISCV_MTVAL = indexof(ExecutionFrame, mtval),
UNW_RISCV_MHARTID = indexof(ExecutionFrame, mhartid),
} riscv_regnum_t;
/**
* @brief Number of registers in the ExecutionFrame structure.
*
* This will be used to define and initialize the DWARF machine state.
* In practice, we only have 16 registers that are callee saved, thus, we could
* only save them and ignore the rest. However, code to calculate mapping of
* CPU registers to DWARF registers would take more than the 16 registers we
* would save... so save all registers.
*/
#define EXECUTION_FRAME_MAX_REGS (32)
/**
* @brief Reference the PC register of the execution frame.
*/
#define EXECUTION_FRAME_PC(frame) ((frame).mepc)
/**
* @brief Reference the SP register of the execution frame.
*/
#define EXECUTION_FRAME_SP(frame) ((frame).sp)
/**
* @brief Index of SP register in the execution frame.
*/
#define EXECUTION_FRAME_SP_REG (indexof(RvExcFrame, sp))
/**
* @brief Get register i of the execution frame.
*/
#define EXECUTION_FRAME_REG(frame, i) (((uint32_t*) (frame))[(i)])
/**
* @brief Get the current context
*/
FORCE_INLINE_ATTR void UNW_GET_CONTEXT(ExecutionFrame* frame) {
__asm__ __volatile__("sw t0, %1(%0)\n"
"auipc t0, 0\n"
"sw t0, %2(%0)\n"
"sw ra, %3(%0)\n"
"sw sp, %4(%0)\n"
"sw gp, %5(%0)\n"
"sw tp, %6(%0)\n"
"sw t1, %7(%0)\n"
"sw t2, %8(%0)\n"
"sw s0, %9(%0)\n"
"sw s1, %10(%0)\n"
"sw a0, %11(%0)\n"
"sw a1, %12(%0)\n"
"sw a2, %13(%0)\n"
"sw a3, %14(%0)\n"
"sw a4, %15(%0)\n"
"sw a5, %16(%0)\n"
"sw a6, %17(%0)\n"
"sw a7, %18(%0)\n"
"sw s2, %19(%0)\n"
"sw s3, %20(%0)\n"
"sw s4, %21(%0)\n"
"sw s5, %22(%0)\n"
"sw s6, %23(%0)\n"
"sw s7, %24(%0)\n"
"sw s8, %25(%0)\n"
"sw s9, %26(%0)\n"
"sw s10, %27(%0)\n"
"sw s11, %28(%0)\n"
"sw t3, %29(%0)\n"
:
: "r" (frame),
"i" (UNW_RISCV_T0 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_PC * ARCH_WORD_SIZE),
"i" (UNW_RISCV_RA * ARCH_WORD_SIZE),
"i" (UNW_RISCV_SP * ARCH_WORD_SIZE),
"i" (UNW_RISCV_GP * ARCH_WORD_SIZE),
"i" (UNW_RISCV_TP * ARCH_WORD_SIZE),
"i" (UNW_RISCV_T1 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_T2 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S0 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S1 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A0 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A1 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A2 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A3 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A4 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A5 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A6 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_A7 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S2 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S3 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S4 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S5 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S6 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S7 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S8 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S9 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S10 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_S11 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_T3 * ARCH_WORD_SIZE)
);
/* GCC doesn't allow us to have more than 30 operands in a single
* __asm__ __volatile__ definition, so we have to split it into 2 */
__asm__ __volatile__("sw t4, %1(%0)\n"
"sw t5, %2(%0)\n"
"sw t6, %3(%0)\n"
"csrr t0, mstatus\n"
"sw t0, %4(%0)\n"
"csrr t0, mtvec\n"
"sw t0, %5(%0)\n"
"csrr t0, mcause\n"
"sw t0, %6(%0)\n"
"csrr t0, mtval\n"
"sw t0, %7(%0)\n"
"csrr t0, mhartid\n"
"sw t0, %8(%0)\n"
/* We have to restore t0 as it may be in use by the function that makes the use of this assembly snippet */
"lw t0, %9(%0)\n"
:
: "r" (frame),
"i" (UNW_RISCV_T4 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_T5 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_T6 * ARCH_WORD_SIZE),
"i" (UNW_RISCV_MSTATUS * ARCH_WORD_SIZE),
"i" (UNW_RISCV_MTVEC * ARCH_WORD_SIZE),
"i" (UNW_RISCV_MCAUSE * ARCH_WORD_SIZE),
"i" (UNW_RISCV_MTVAL * ARCH_WORD_SIZE),
"i" (UNW_RISCV_MHARTID * ARCH_WORD_SIZE),
"i" (UNW_RISCV_T0 * ARCH_WORD_SIZE)
);
}
#ifdef __cplusplus
}
#endif