rtt.patch

From 92402217b821c8da7e2a188352f095caaf0818d1 Mon Sep 17 00:00:00 2001
From: tangzz98 <tangz98@outlook.com>
Date: Tue, 13 Sep 2022 18:05:44 -0400
Subject: [PATCH 1/2] Add config for RT-Thread

---
 Kconfig                                       |   4 +
 components/driver/deprecated/i2s_legacy.c     |   4 +
 components/driver/uart.c                      |   4 +
 components/esp_system/crosscore_int.c         |   5 +-
 .../esp_system/ld/esp32c3/sections.ld.in      |  37 ++++
 .../port/arch/riscv/expression_with_stack.c   |   8 +
 components/esp_system/startup.c               |   9 +
 components/esp_system/task_wdt.c              |   4 +
 components/esp_timer/src/esp_timer.c          |   2 +
 components/freertos/CMakeLists.txt            |  50 ++++-
 .../freertos_tasks_c_additions.h              |   6 +-
 components/riscv/vectors.S                    | 179 ++++++++++++++++++
 12 files changed, 309 insertions(+), 3 deletions(-)

diff --git a/Kconfig b/Kconfig
index c86ebeaaef..56d062b2db 100644
--- a/Kconfig
+++ b/Kconfig
@@ -101,6 +101,10 @@ mainmenu "Espressif IoT Development Framework Configuration"
         bool
         default "y" if IDF_TARGET="linux"
 
+    config IDF_RTOS_RTTHREAD
+        bool "RT-THREAD SELECT"
+        default "n" 
+
     config IDF_FIRMWARE_CHIP_ID
         hex
         default 0x0000 if IDF_TARGET_ESP32
diff --git a/components/driver/deprecated/i2s_legacy.c b/components/driver/deprecated/i2s_legacy.c
index 2e36ab2608..92edf9d2bb 100644
--- a/components/driver/deprecated/i2s_legacy.c
+++ b/components/driver/deprecated/i2s_legacy.c
@@ -1600,7 +1600,11 @@ esp_err_t i2s_driver_install(i2s_port_t i2s_num, const i2s_config_t *i2s_config,
         i2s_obj->i2s_queue = xQueueCreate(queue_size, sizeof(i2s_event_t));
         ESP_GOTO_ON_FALSE(i2s_obj->i2s_queue, ESP_ERR_NO_MEM, err, TAG, "I2S queue create failed");
         *((QueueHandle_t *) i2s_queue) = i2s_obj->i2s_queue;
+#if !defined CONFIG_IDF_RTOS_RTTHREAD
         ESP_LOGD(TAG, "queue free spaces: %d", uxQueueSpacesAvailable(i2s_obj->i2s_queue));
+#else
+        ESP_LOGD(TAG, "queue free spaces: %lu", uxQueueSpacesAvailable(i2s_obj->i2s_queue));
+#endif
     } else {
         i2s_obj->i2s_queue = NULL;
     }
diff --git a/components/driver/uart.c b/components/driver/uart.c
index b68b2900e1..63c9841380 100644
--- a/components/driver/uart.c
+++ b/components/driver/uart.c
@@ -1603,7 +1603,11 @@ esp_err_t uart_driver_install(uart_port_t uart_num, int rx_buffer_size, int tx_b
         uart_pattern_queue_reset(uart_num, UART_PATTERN_DET_QLEN_DEFAULT);
         if (uart_queue) {
             *uart_queue = p_uart_obj[uart_num]->event_queue;
+#if !defined CONFIG_IDF_RTOS_RTTHREAD
             ESP_LOGI(UART_TAG, "queue free spaces: %d", uxQueueSpacesAvailable(p_uart_obj[uart_num]->event_queue));
+#else
+            ESP_LOGI(UART_TAG, "queue free spaces: %lu", uxQueueSpacesAvailable(p_uart_obj[uart_num]->event_queue));
+#endif
         }
     } else {
         ESP_LOGE(UART_TAG, "UART driver already installed");
diff --git a/components/esp_system/crosscore_int.c b/components/esp_system/crosscore_int.c
index 4aae2a2540..8a9079de64 100644
--- a/components/esp_system/crosscore_int.c
+++ b/components/esp_system/crosscore_int.c
@@ -95,13 +95,14 @@ static void IRAM_ATTR esp_crosscore_isr(void *arg) {
     if (my_reason_val & REASON_PRINT_BACKTRACE) {
         esp_backtrace_print(100);
     }
-
+#ifdef CONFIG_ESP_TASK_WDT
     if (my_reason_val & REASON_TWDT_ABORT) {
         extern void task_wdt_timeout_abort_xtensa(bool);
         /* Called from a crosscore interrupt, thus, we are not the core that received
          * the TWDT interrupt, call the function with `false` as a parameter. */
         task_wdt_timeout_abort_xtensa(false);
     }
+#endif
 #endif // CONFIG_IDF_TARGET_ARCH_XTENSA
 }
 
@@ -171,7 +172,9 @@ void IRAM_ATTR esp_crosscore_int_send_print_backtrace(int core_id)
     esp_crosscore_int_send(core_id, REASON_PRINT_BACKTRACE);
 }
 
+#ifdef CONFIG_ESP_TASK_WDT
 void IRAM_ATTR esp_crosscore_int_send_twdt_abort(int core_id) {
     esp_crosscore_int_send(core_id, REASON_TWDT_ABORT);
 }
 #endif
+#endif
diff --git a/components/esp_system/ld/esp32c3/sections.ld.in b/components/esp_system/ld/esp32c3/sections.ld.in
index d6670bf759..1d51ffeea0 100644
--- a/components/esp_system/ld/esp32c3/sections.ld.in
+++ b/components/esp_system/ld/esp32c3/sections.ld.in
@@ -178,6 +178,26 @@ SECTIONS
     _noinit_end = ABSOLUTE(.);
   } > dram0_0_seg
 
+  .stack :
+  {
+      . = ALIGN(8);
+      __STACKSIZE__ = 40960; 
+      __stack_start__ = .;
+      *(.stack*)
+      . += __STACKSIZE__;
+      __stack_cpu0 = .;
+      __stack_end__ = .;
+  } > dram0_0_seg
+
+  .heap :
+  {
+      . = ALIGN(8);
+      __HEAPSIZE__ = 40960; 
+      __heap_start__ = .;
+      . += __HEAPSIZE__;
+      __heap_end__ = .;
+  } > dram0_0_seg
+
   /* Shared RAM */
   .dram0.bss (NOLOAD) :
   {
@@ -218,6 +238,17 @@ SECTIONS
     *(.fini)
     *(.gnu.version)
 
+    /* section information for finsh shell */
+    . = ALIGN(8);
+    __fsymtab_start = .;
+    KEEP(*(FSymTab))
+    __fsymtab_end = .;
+    . = ALIGN(8);
+    __vsymtab_start = .;
+    KEEP(*(VSymTab))
+    __vsymtab_end = .;
+    . = ALIGN(8);
+
     /** CPU will try to prefetch up to 16 bytes of
       * of instructions. This means that any configuration (e.g. MMU, PMS) must allow
       * safe access to up to 16 bytes after the last real instruction, add
@@ -318,6 +349,12 @@ SECTIONS
     _esp_system_init_fn_array_start = ABSOLUTE(.);
     KEEP (*(SORT_BY_INIT_PRIORITY(.esp_system_init_fn.*)))
     _esp_system_init_fn_array_end = ABSOLUTE(.);
+    /* section information for initial. */
+    . = ALIGN(4);
+    __rt_init_start = .;
+    KEEP(*(SORT(.rti_fn*)))
+    __rt_init_end = .;
+    . = ALIGN(4);
     _rodata_end = ABSOLUTE(.);
     /* Literals are also RO data. */
     _lit4_start = ABSOLUTE(.);
diff --git a/components/esp_system/port/arch/riscv/expression_with_stack.c b/components/esp_system/port/arch/riscv/expression_with_stack.c
index 07d22bf3aa..5eac5a88f8 100644
--- a/components/esp_system/port/arch/riscv/expression_with_stack.c
+++ b/components/esp_system/port/arch/riscv/expression_with_stack.c
@@ -18,6 +18,8 @@
 #include "freertos/FreeRTOS.h"
 #include "freertos/portmacro.h"
 
+#if !defined CONFIG_IDF_RTOS_RTTHREAD
+
 static portMUX_TYPE shared_stack_spinlock = portMUX_INITIALIZER_UNLOCKED;
 static void *current_task_stack = NULL;
 
@@ -46,9 +48,12 @@ static StackType_t *esp_switch_stack_setup(StackType_t *stack, size_t stack_size
     return ((StackType_t *)adjusted_top_of_stack);
 }
 
+#endif
+
 
 void esp_execute_shared_stack_function(SemaphoreHandle_t lock, void *stack, size_t stack_size, shared_stack_function function)
 {
+#if !defined CONFIG_IDF_RTOS_RTTHREAD
     assert(lock);
     assert(stack);
     assert(stack_size > 0 && stack_size >= CONFIG_ESP_MINIMAL_SHARED_STACK_SIZE);
@@ -70,4 +75,7 @@ void esp_execute_shared_stack_function(SemaphoreHandle_t lock, void *stack, size
     portEXIT_CRITICAL(&shared_stack_spinlock);
 
     xSemaphoreGive(lock);
+#else
+    function();
+#endif
 }
diff --git a/components/esp_system/startup.c b/components/esp_system/startup.c
index 0feda4e9f5..b1752d91a0 100644
--- a/components/esp_system/startup.c
+++ b/components/esp_system/startup.c
@@ -72,6 +72,10 @@
 #include "esp_psram.h"
 #include "esp_private/esp_psram_extram.h"
 #endif
+
+#if CONFIG_IDF_RTOS_RTTHREAD
+#include "rtthread.h"
+#endif
 /***********************************************/
 
 #include "esp_private/startup_internal.h"
@@ -266,6 +270,11 @@ static void do_core_init(void)
        app CPU, and when that is not up yet, the memory will be inaccessible and heap_caps_init may
        fail initializing it properly. */
     heap_caps_init();
+#if CONFIG_IDF_RTOS_RTTHREAD && defined RT_USING_HEAP
+    extern int __heap_start__;
+    extern int __heap_end__;
+    rt_system_heap_init((void *)&__heap_start__, (void *)&__heap_end__);
+#endif
 
     // When apptrace module is enabled, there will be SEGGER_SYSVIEW calls in the newlib init.
     // SEGGER_SYSVIEW relies on apptrace module
diff --git a/components/esp_system/task_wdt.c b/components/esp_system/task_wdt.c
index 58d1247bf0..60330edf8a 100644
--- a/components/esp_system/task_wdt.c
+++ b/components/esp_system/task_wdt.c
@@ -29,6 +29,8 @@
 #include "esp_private/eh_frame_parser.h"
 #endif // CONFIG_ESP_SYSTEM_USE_EH_FRAME
 
+#if CONFIG_ESP_TASK_WDT
+
 #if CONFIG_IDF_TARGET_ARCH_RISCV && !CONFIG_ESP_SYSTEM_USE_EH_FRAME
 /* Function used to print all the registers pointed by the given frame .*/
 extern void panic_print_registers(const void *frame, int core);
@@ -784,3 +786,5 @@ esp_err_t esp_task_wdt_status(TaskHandle_t task_handle)
 
     return ret;
 }
+
+#endif
diff --git a/components/esp_timer/src/esp_timer.c b/components/esp_timer/src/esp_timer.c
index 3ca19f642f..78779a08b3 100644
--- a/components/esp_timer/src/esp_timer.c
+++ b/components/esp_timer/src/esp_timer.c
@@ -460,10 +460,12 @@ out:
     return ESP_ERR_NO_MEM;
 }
 
+#if !defined CONFIG_IDF_RTOS_RTTHREAD
 ESP_SYSTEM_INIT_FN(esp_timer_startup_init, BIT(0), 100)
 {
     return esp_timer_init();
 }
+#endif
 
 esp_err_t esp_timer_deinit(void)
 {
diff --git a/components/freertos/CMakeLists.txt b/components/freertos/CMakeLists.txt
index 78a8e4ae4e..5cd54494f6 100644
--- a/components/freertos/CMakeLists.txt
+++ b/components/freertos/CMakeLists.txt
@@ -6,7 +6,36 @@ endif()
 
 idf_build_get_property(target IDF_TARGET)
 
-if(CONFIG_FREERTOS_SMP)
+if(CONFIG_IDF_RTOS_RTTHREAD)
+    set(freertos_root "../../../FreeRTOS_Wrapper-latest/FreeRTOS")
+    set(srcs
+        "${freertos_root}/portable/esp-idf/riscv/port.c")
+
+    set(include_dirs
+        "${freertos_root}/include"
+        esp_additions/include
+        esp_additions/include/freertos
+        "${freertos_root}/portable/esp-idf/riscv/include")
+
+    set(private_include_dirs
+        "${freertos_root}/portable/esp-idf/riscv/include/freertos")
+
+    list(APPEND srcs
+        "${freertos_root}/portable/esp-idf/port_common.c"
+        "${freertos_root}/portable/esp-idf/port_rt.c"
+        "${freertos_root}/event_groups.c"
+        "${freertos_root}/queue.c"
+        "${freertos_root}/tasks.c"
+        "${freertos_root}/timers.c"
+        "${freertos_root}/list.c"
+        "FreeRTOS-openocd.c"
+        "esp_additions/freertos_v8_compat.c")
+
+    list(APPEND private_include_dirs
+        "${freertos_root}/include/freertos"
+        "esp_additions/private_include")
+
+elseif(CONFIG_FREERTOS_SMP)
     set(ldfragments linker_smp.lf)
     if(CONFIG_IDF_TARGET_ARCH_XTENSA)
         set(srcs
@@ -133,11 +162,19 @@ else()
     endif()
 endif()
 
+if(CONFIG_IDF_RTOS_RTTHREAD)
+idf_component_register(SRCS "${srcs}"
+                    INCLUDE_DIRS ${include_dirs}
+                    PRIV_INCLUDE_DIRS  ${private_include_dirs}
+                    PRIV_REQUIRES soc esp_pm)
+else()
 idf_component_register(SRCS "${srcs}"
                     INCLUDE_DIRS ${include_dirs}
                     PRIV_INCLUDE_DIRS  ${private_include_dirs}
                     LDFRAGMENTS "${ldfragments}"
+                    REQUIRES main
                     PRIV_REQUIRES soc esp_pm)
+endif()
 
 idf_component_get_property(COMPONENT_DIR freertos COMPONENT_DIR)
 
@@ -153,6 +190,16 @@ if(CONFIG_FREERTOS_DEBUG_OCDAWARE)
     idf_build_set_property(COMPILE_OPTIONS "-DconfigENABLE_FREERTOS_DEBUG_OCDAWARE=1" APPEND)
 endif()
 
+if(CONFIG_IDF_RTOS_RTTHREAD)
+set_source_files_properties(
+    tasks.c
+    event_groups.c
+    timers.c
+    queue.c
+    PROPERTIES COMPILE_DEFINITIONS
+    _ESP_FREERTOS_INTERNAL
+    )
+else()
 set_source_files_properties(
     tasks.c
     event_groups.c
@@ -162,6 +209,7 @@ set_source_files_properties(
     PROPERTIES COMPILE_DEFINITIONS
     _ESP_FREERTOS_INTERNAL
     )
+endif()
 
 # The freertos component provides the `start_app` and `start_app_other_cores`
 # if it is included in the build. It then calls `app_main`
diff --git a/components/freertos/esp_additions/private_include/freertos_tasks_c_additions.h b/components/freertos/esp_additions/private_include/freertos_tasks_c_additions.h
index f5ecdbb5a9..96fc4f73ce 100644
--- a/components/freertos/esp_additions/private_include/freertos_tasks_c_additions.h
+++ b/components/freertos/esp_additions/private_include/freertos_tasks_c_additions.h
@@ -34,8 +34,9 @@
 struct _reent *__getreent(void)
 {
     // No lock needed because if this changes, we won't be running anymore.
-    TCB_t *pxCurTask = xTaskGetCurrentTaskHandle();
     struct _reent *ret;
+#if !defined CONFIG_IDF_RTOS_RTTHREAD
+    TCB_t *pxCurTask = xTaskGetCurrentTaskHandle();
     if (pxCurTask == NULL) {
         // No task running. Return global struct.
         ret = _GLOBAL_REENT;
@@ -43,6 +44,9 @@ struct _reent *__getreent(void)
         // We have a task; return its reentrant struct.
         ret = &pxCurTask->xNewLib_reent;
     }
+#else
+    ret = _GLOBAL_REENT;
+#endif
     return ret;
 }
 #endif // configUSE_NEWLIB_REENTRANT == 1
diff --git a/components/riscv/vectors.S b/components/riscv/vectors.S
index 9b868280db..23236f3d8d 100644
--- a/components/riscv/vectors.S
+++ b/components/riscv/vectors.S
@@ -10,6 +10,9 @@
 #include "soc/soc_caps.h"
 #include "sdkconfig.h"
 
+#define STORE                   sw
+#define LOAD                    lw
+#define REGBYTES                4
 
     .equ SAVE_REGS, 32
     .equ CONTEXT_SIZE, (SAVE_REGS * 4)
@@ -210,6 +213,8 @@ _return_from_exception:
      */
     .global _interrupt_handler
     .type _interrupt_handler, @function
+#ifndef CONFIG_IDF_RTOS_RTTHREAD
+
 _interrupt_handler:
     /* Start by saving the general purpose registers and the PC value before
      * the interrupt happened. */
@@ -308,3 +313,177 @@ _interrupt_handler:
     /* exit, this will also re-enable the interrupts */
     mret
     .size  _interrupt_handler, .-_interrupt_handler
+#else
+_interrupt_handler:
+    /* 此时CPU的sp = from_thread->sp */
+    /* 注意： 在这里，并没有将mepc的值赋值为from_thread栈中的epc，但后面会赋值 */
+    addi sp, sp, -32 * REGBYTES             /* sp = sp - 32 * 4 栈指针向下偏移32个寄存器长度，用来将CPU的寄存器保存到from_thread的栈中*/
+    STORE x1,   1 * REGBYTES(sp)            /* 将CPU的x1寄存器，即ra寄存器，保存到from_thread->栈中 */
+
+    li    t0,   0x80                        /* t0 = 0x80 */
+    STORE t0,   2 * REGBYTES(sp)            /* mstatus = t0, 即关闭全局中断 */
+
+    /* 将 CPU 的其他寄存器的值，保存到from_thread的任务栈中 */
+    STORE x4,   4 * REGBYTES(sp)
+    STORE x5,   5 * REGBYTES(sp)
+    STORE x6,   6 * REGBYTES(sp)
+    STORE x7,   7 * REGBYTES(sp)
+    STORE x8,   8 * REGBYTES(sp)
+    STORE x9,   9 * REGBYTES(sp)
+    STORE x10, 10 * REGBYTES(sp)
+    STORE x11, 11 * REGBYTES(sp)
+    STORE x12, 12 * REGBYTES(sp)
+    STORE x13, 13 * REGBYTES(sp)
+    STORE x14, 14 * REGBYTES(sp)
+    STORE x15, 15 * REGBYTES(sp)
+    STORE x16, 16 * REGBYTES(sp)
+    STORE x17, 17 * REGBYTES(sp)
+    STORE x18, 18 * REGBYTES(sp)
+    STORE x19, 19 * REGBYTES(sp)
+    STORE x20, 20 * REGBYTES(sp)
+    STORE x21, 21 * REGBYTES(sp)
+    STORE x22, 22 * REGBYTES(sp)
+    STORE x23, 23 * REGBYTES(sp)
+    STORE x24, 24 * REGBYTES(sp)
+    STORE x25, 25 * REGBYTES(sp)
+    STORE x26, 26 * REGBYTES(sp)
+    STORE x27, 27 * REGBYTES(sp)
+    STORE x28, 28 * REGBYTES(sp)
+    STORE x29, 29 * REGBYTES(sp)
+    STORE x30, 30 * REGBYTES(sp)
+    STORE x31, 31 * REGBYTES(sp)
+
+    /* 备份 CPU 的 sp (这时，CPU的sp其实就是from thread的sp指针) 寄存器的值到 s0 寄存器中，下面会使用s0，恢复 CPU 的寄存器 */
+    move  s0, sp    /* s0 = sp */
+
+    /* 在中断函数中，中断函数中调用的C函数，需要使用 sp， 这里，在中断函数中，使用的 sp 为，系统的栈资源 */
+    /* switch to interrupt stack */
+    la    sp, __stack_end__   /* sp = _sp */
+
+    /* interrupt handle */
+    /* 注意： 在调用C函数之前,比如sp的值为0x30001000, 在执行完C函数后，sp的值还是会变成 0x30001000 */
+    call  rt_interrupt_enter    /* 执行所有的中断函数前，调用该函数 */
+
+    csrr s1, mcause
+	csrr s2, mstatus
+
+    /* Save the interrupt threshold level */
+	la t0, INTERRUPT_CORE0_CPU_INT_THRESH_REG
+	lw s3, 0(t0)
+
+    li t2, 0x7fffffff
+	and t1, s1, t2		/* t1 = mcause & mask */
+	slli t1, t1, 2 		/* t1 = mcause * 4 */
+	la t2, INTC_INT_PRIO_REG(0)
+	add t1, t2, t1		/* t1 = INTC_INT_PRIO_REG + 4 * mcause */
+	lw t2, 0(t1)		/* t2 = INTC_INT_PRIO_REG[mcause] */
+	addi t2, t2, 1		/* t2 = t2 +1 */
+	sw t2, 0(t0)		/* INTERRUPT_CORE0_CPU_INT_THRESH_REG = t2 */
+	fence
+
+    li t0, 0x8
+	csrrs t0, mstatus, t0
+
+    /* call the C dispatcher */
+	mv      a0, sp      /* argument 1, stack pointer */
+	mv      a1, s1      /* argument 2, interrupt number (mcause) */
+	/* mask off the interrupt flag of mcause */
+	li	    t0, 0x7fffffff
+	and     a1, a1, t0
+	jal     _global_interrupt_handler
+
+    li t0, 0x8
+	csrrc t0, mstatus, t0
+
+	/* restore the interrupt threshold level */
+	la t0, INTERRUPT_CORE0_CPU_INT_THRESH_REG
+	sw s3, 0(t0)
+	fence
+
+    call  rt_interrupt_leave    /* 执行所有的中断函数后，调用该函数 */
+
+    /* 上面，将保存执行中断服务函数之前的CPU的sp寄存器到了s0所指向的位置处，当执行完中断服务函数，需要将之前的CPU寄存器，恢复一下,此时sp又变成了from thread的sp了 */
+    move  sp, s0    /* sp = s0 */
+
+    /* 下面两句话，相当于将 rt_thread_switch_interrupt_flag 值，赋值给了s2  */
+    /* 将 rt_thread_switch_interrupt_flag 的地址值，赋值给 s0 寄存器*/
+    la    s0, rt_thread_switch_interrupt_flag       /* s0 = &rt_thread_switch_interrupt_flag */
+    /* 将 s0 所指向的地址处的内容，取出来，赋值给 s2 寄存器，其实就是将  rt_thread_switch_interrupt_flag 的值，赋值给了 s2 寄存器*/
+    lw    s2, 0(s0)                 /* s2 = *s0 = rt_thread_switch_interrupt_flag */
+
+    /* 如果 s2的值，即 rt_thread_switch_interrupt_flag 值，如果不为0，则需要继续执行下一条指令，如果为0，则需要跳转到 spurious_interrupt 标号处 执行 */
+    /* 如果 s2的值等于0，rt_thread_switch_interrupt_flag等于0， 则不需要在中断处理函数中，进行上下文切换，反之则需要 */
+    /* 如果不需要上下文切换， */
+
+    /* 在这里，跳转到 spurious_interrupt的话，是不会进行上下文切换的，因为，此时CPU的sp指针还是from线程的*/
+    beqz  s2, spurious_interrupt    /* if (s2 == 0) goto spurious_interrupt; else 执行下一条语句*/
+
+    /* 需要上下文切换： 主要目的是将CPU的sp指针，赋值为to_thread的sp */
+
+    /* 将 s0 所执向的地址的内容设置为0， 也就是，将变量 rt_thread_switch_interrupt_flag 赋值为了 0 */
+    /* s0存放的值是 rt_thread_switch_interrupt_flag 变量的地址*/
+    sw    zero, 0(s0)       /* *s0 = 0; 也就是 rt_thread_switch_interrupt_flag = 0 */
+    /* 将 mepc 的值，赋值给 a0 寄存器，mepc 的值是，跳转到中断函数执行之前的 PC 指针 */
+    /* 这时的mpec其实，还是from线程，在跳转到中断执行前的一个PC地址 */
+    csrr  a0, mepc  /* a0 = mepc */
+
+    /* 将 mpec 的值写回到freom thread任务栈中的 epc 中,待后续，恢复from线程时，使用 */
+    STORE a0, 0 * REGBYTES(sp)  /* from_thread->sp->epc = a0 ，中断入口处*/
+
+    /* 将from_thread的sp指针，赋值为CPU的sp指针 */
+    la    s0, rt_interrupt_from_thread  /* s0 = &rt_interrupt_from_thread 注意： rt_interrupt_from_thread = &(from_thread->sp) */
+    LOAD  s1, 0(s0)                     /* s1 = rt_interrupt_from_thread，也就是s1 = &(from_thread->sp) */
+    STORE sp, 0(s1)                     /* from_thread->sp = sp*/
+
+    /* 接下来，需要开始恢复CPU的sp为to_thread的sp了 */
+    la    s0, rt_interrupt_to_thread    /* s0 = &rt_interrupt_to_thread 注意： rt_interrupt_to_thread = &(to_thred->sp)*/
+    LOAD  s1, 0(s0)                     /* s1 = rt_interrupt_to_thread, 也就是s1 = &(to_thred->sp) */
+    LOAD  sp, 0(s1)                     /* sp = (to_thred->sp)*/
+
+    /* 将CPU的 mepc设置为to_thred的mepc，待中断退出，执行mret指令后，将从该地址开始执行 */
+    LOAD  a0,  0 * REGBYTES(sp)         /* a0 = to_thread的mepc的值*/
+    csrw  mepc, a0                      /* mepc = a0 */
+
+
+spurious_interrupt:
+    LOAD  x1,   1 * REGBYTES(sp)
+
+    /* Remain in M-mode after mret */
+    li    t0, 0x00001800
+    csrs  mstatus, t0
+    LOAD  t0,   2 * REGBYTES(sp)
+    csrs  mstatus, t0
+
+    LOAD  x4,   4 * REGBYTES(sp)
+    LOAD  x5,   5 * REGBYTES(sp)
+    LOAD  x6,   6 * REGBYTES(sp)
+    LOAD  x7,   7 * REGBYTES(sp)
+    LOAD  x8,   8 * REGBYTES(sp)
+    LOAD  x9,   9 * REGBYTES(sp)
+    LOAD  x10, 10 * REGBYTES(sp)
+    LOAD  x11, 11 * REGBYTES(sp)
+    LOAD  x12, 12 * REGBYTES(sp)
+    LOAD  x13, 13 * REGBYTES(sp)
+    LOAD  x14, 14 * REGBYTES(sp)
+    LOAD  x15, 15 * REGBYTES(sp)
+    LOAD  x16, 16 * REGBYTES(sp)
+    LOAD  x17, 17 * REGBYTES(sp)
+    LOAD  x18, 18 * REGBYTES(sp)
+    LOAD  x19, 19 * REGBYTES(sp)
+    LOAD  x20, 20 * REGBYTES(sp)
+    LOAD  x21, 21 * REGBYTES(sp)
+    LOAD  x22, 22 * REGBYTES(sp)
+    LOAD  x23, 23 * REGBYTES(sp)
+    LOAD  x24, 24 * REGBYTES(sp)
+    LOAD  x25, 25 * REGBYTES(sp)
+    LOAD  x26, 26 * REGBYTES(sp)
+    LOAD  x27, 27 * REGBYTES(sp)
+    LOAD  x28, 28 * REGBYTES(sp)
+    LOAD  x29, 29 * REGBYTES(sp)
+    LOAD  x30, 30 * REGBYTES(sp)
+    LOAD  x31, 31 * REGBYTES(sp)
+
+    addi  sp, sp, 32 * REGBYTES
+    mret
+	.size  _interrupt_handler, .-_interrupt_handler
+#endif
\ No newline at end of file
-- 
2.32.0 (Apple Git-132)


From 394259fb2164e513abd4f0d23d88da92c2a2ac9e Mon Sep 17 00:00:00 2001
From: tangzz98 <tangz98@outlook.com>
Date: Fri, 23 Sep 2022 00:12:13 -0400
Subject: [PATCH 2/2] Specify freertos_root in project CMakeLists.txt

---
 components/freertos/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/freertos/CMakeLists.txt b/components/freertos/CMakeLists.txt
index 5cd54494f6..33c901c187 100644
--- a/components/freertos/CMakeLists.txt
+++ b/components/freertos/CMakeLists.txt
@@ -7,7 +7,7 @@ endif()
 idf_build_get_property(target IDF_TARGET)
 
 if(CONFIG_IDF_RTOS_RTTHREAD)
-    set(freertos_root "../../../FreeRTOS_Wrapper-latest/FreeRTOS")
+    message(${freertos_root})
     set(srcs
         "${freertos_root}/portable/esp-idf/riscv/port.c")
 
-- 
2.32.0 (Apple Git-132)