rt-thread-official/bsp/ESP32_C3/0001-add-the-config-of-RTTHREAD.patch

From 317ee995e9d530587bfb14439b3b1ee38d1afe77 Mon Sep 17 00:00:00 2001
From: supperthomas <78900636@qq.com>
Date: Fri, 6 May 2022 23:06:28 +0800
Subject: [PATCH] add the config of RTTHREAD

add the init link file
---
 Kconfig                                       |   4 +
 .../esp_system/ld/esp32c3/sections.ld.in      |  26 +++
 components/freertos/port/port_common.c        |   5 +
 components/freertos/port/port_systick.c       |   3 +
 components/riscv/vectors.S                    | 220 ++++++++++++++++--
 5 files changed, 239 insertions(+), 19 deletions(-)

diff --git a/Kconfig b/Kconfig
index 928d274106..d368adaa37 100644
--- a/Kconfig
+++ b/Kconfig
@@ -61,6 +61,10 @@ 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/esp_system/ld/esp32c3/sections.ld.in b/components/esp_system/ld/esp32c3/sections.ld.in
index 0ebeda06c1..8215237fff 100644
--- a/components/esp_system/ld/esp32c3/sections.ld.in
+++ b/components/esp_system/ld/esp32c3/sections.ld.in
@@ -183,6 +183,32 @@ SECTIONS
     _noinit_end = ABSOLUTE(.);
   } > dram0_0_seg
 
+  .stack_dummy (COPY):
+  {
+      . = ALIGN(8);
+       __STACKSIZE__ = 40960; 
+      __stack_start__ = .;
+      *(.stack*)
+      . += __STACKSIZE__;
+      __stack_cpu0 = .;
+      __stack_end__ = .;
+  } > dram0_0_seg
+
+  .stack_dummy (COPY):
+  {
+      . = ALIGN(8);
+       __HEAPSIZE__ = 40960; 
+      __heap_start__ = .;
+      . += __STACKSIZE__;
+      __heap_end__ = .;
+        /* section information for initial. */
+        . = ALIGN(4);
+        __rt_init_start = .;
+        KEEP(*(SORT(.rti_fn*)))
+        __rt_init_end = .;
+
+        . = ALIGN(4);
+  } > dram0_0_seg
   /* Shared RAM */
   .dram0.bss (NOLOAD) :
   {
diff --git a/components/freertos/port/port_common.c b/components/freertos/port/port_common.c
index ffca3d5429..9d8159f588 100644
--- a/components/freertos/port/port_common.c
+++ b/components/freertos/port/port_common.c
@@ -74,11 +74,16 @@ void esp_startup_start_app_common(void)
     esp_gdbstub_init();
 #endif // CONFIG_ESP_SYSTEM_GDBSTUB_RUNTIME
 
+#ifdef CONFIG_IDF_RTOS_RTTHREAD
+    app_main();
+#else
     portBASE_TYPE res = xTaskCreatePinnedToCore(&main_task, "main",
                                                 ESP_TASK_MAIN_STACK, NULL,
                                                 ESP_TASK_MAIN_PRIO, NULL, ESP_TASK_MAIN_CORE);
     assert(res == pdTRUE);
     (void)res;
+#endif
+
 }
 
 static void main_task(void* args)
diff --git a/components/freertos/port/port_systick.c b/components/freertos/port/port_systick.c
index 0c14a155a1..0fa203574b 100644
--- a/components/freertos/port/port_systick.c
+++ b/components/freertos/port/port_systick.c
@@ -116,6 +116,8 @@ void vPortSetupTimer(void)
  */
 IRAM_ATTR void SysTickIsrHandler(void *arg)
 {
+#ifdef CONFIG_IDF_RTOS_RTTHREAD
+#else
     uint32_t cpuid = xPortGetCoreID();
     systimer_hal_context_t *systimer_hal = (systimer_hal_context_t *)arg;
 #ifdef CONFIG_PM_TRACE
@@ -144,6 +146,7 @@ IRAM_ATTR void SysTickIsrHandler(void *arg)
 #ifdef CONFIG_PM_TRACE
     ESP_PM_TRACE_EXIT(TICK, cpuid);
 #endif
+#endif
 }
 
 #endif // CONFIG_FREERTOS_SYSTICK_USES_CCOUNT
diff --git a/components/riscv/vectors.S b/components/riscv/vectors.S
index 1006d5bea5..963494fcb3 100644
--- a/components/riscv/vectors.S
+++ b/components/riscv/vectors.S
@@ -17,6 +17,9 @@
 #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)
@@ -218,25 +221,27 @@ _call_panic_handler:
 	 */
 	.global _interrupt_handler
 	.type _interrupt_handler, @function
+#ifndef CONFIG_IDF_RTOS_RTTHREAD
+
 _interrupt_handler:
 	/* entry */
-	save_regs
-	save_mepc
+	save_regs   /* 保存寄存器 */
+	save_mepc   /* 保存MEPC */
 
 	/* Before doing anythig preserve the stack pointer */
 	/* It will be saved in current TCB, if needed */
-	mv a0, sp
+	mv a0, sp            /* 保存SP  a0 = sp */
 	call rtos_int_enter
 
 	/* Before dispatch c handler, restore interrupt to enable nested intr */
-	csrr s1, mcause
-	csrr s2, mstatus
+	csrr s1, mcause    /* 保存mcause s1 = mcause */
+	csrr s2, mstatus  /* 保存mstatus  s2 = mstatus */
 
-	/* Save the interrupt threshold level */
-	la t0, INTERRUPT_CORE0_CPU_INT_THRESH_REG
-	lw s3, 0(t0)
+	/* Save the interrupt threshold level 保存中断嵌套层数? */
+	la t0, INTERRUPT_CORE0_CPU_INT_THRESH_REG  /* 保存mstatus  t0 = &INTERRUPT_CORE0_CPU_INT_THRESH_REG */
+	lw s3, 0(t0)    /*   s3 = mstatus */
 
-	/* Increase interrupt threshold level */
+	/* Increase interrupt threshold level 增加中断嵌套层数*/
 	li t2, 0x7fffffff
 	and t1, s1, t2		/* t1 = mcause & mask */
 	slli t1, t1, 2 		/* t1 = mcause * 4 */
@@ -247,8 +252,8 @@ _interrupt_handler:
 	sw t2, 0(t0)		/* INTERRUPT_CORE0_CPU_INT_THRESH_REG = t2 */
 	fence
 
-	li t0, 0x8
-	csrrs t0, mstatus, t0
+	li t0, 0x8   /* t0 = 8 */
+	csrrs t0, mstatus, t0    /*设置状态MIE寄存器，开总中断*/
 
 	#ifdef CONFIG_PM_TRACE
 	li      a0, 0       /* = ESP_PM_TRACE_IDLE */
@@ -269,34 +274,211 @@ _interrupt_handler:
 	/* 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 */
+	/* mask off the interrupt flag of mcause   屏幕异常中断*/
 	li	    t0, 0x7fffffff
 	and     a1, a1, t0
 	jal     _global_interrupt_handler
 
-	/* After dispatch c handler, disable interrupt to make freertos make context switch */
+	/* After dispatch c handler, disable interrupt to make freertos make context switch 
+	在调用c函数之后，disable 中断让freertos能够做内容切换
+	*/
 
 	li t0, 0x8
-	csrrc t0, mstatus, t0
+	csrrc t0, mstatus, t0  /*清状态MIE寄存器 关总中断*/
 
-	/* restore the interrupt threshold level */
+
+	/* restore the interrupt threshold level  中断嵌套 */
 	la t0, INTERRUPT_CORE0_CPU_INT_THRESH_REG
 	sw s3, 0(t0)
 	fence
 
 	/* Yield to the next task is needed: */
-	mv a0, sp
+	mv a0, sp     /* a0 = sp*/
 	call rtos_int_exit
 
 	/* The next (or current) stack pointer is returned in a0 */
-	mv sp, a0
+	mv sp, a0    /* sp = a0*/
 
 	/* restore the rest of the registers */
-	csrw mcause, s1
-	csrw mstatus, s2
+	csrw mcause, s1  /* mcause = s1 */
+	csrw mstatus, s2   /* mstatus = s2 */
 	restore_mepc
 	restore_regs
 
 	/* 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
-- 
2.35.1.windows.2