CPU有哪几种工作模式?每种模式都有独立堆栈,如何用汇编初始化这些栈?

    搜索 @note_pic 可查看绘制的全部字符图
    搜索 @note_why 是尚未看明白的地方，有看明白的，请Pull Request完善
    搜索 @note_thinking 是一些的思考和建议
    搜索 @note_#if0 是由第三方项目提供不在内核源码中定义的极为重要结构体，为方便理解而添加的。
    搜索 @note_good 是给源码点赞的地方

arch/arm/arm/src/los_dispatch.S

@@ -42,28 +42,28 @@
     .global   OsIrqHandler		/*硬中断处理*/
     .global   ArchSpinUnlock	/*自旋锁解锁*/
     .global   OsSchedToUserSpinUnlock /*尚未实现*/
-
+	/* @note_why 为何要重新定义OS_TASK_STATUS_RUNNING? */
     .equ OS_TASK_STATUS_RUNNING,       0x0010U /* .equ用于把常量值设置为可以在文本段中使用的符号 #define OS_TASK_STATUS_RUNNING 0x0010U */
     .equ OS_PERCPU_STRUCT_SIZE,        0x28U
     .equ OS_PERCPU_TASK_LOCK_OFFSET,   0x14U
     .fpu vfpv4 /* .fpu @note_why 尚未知这句话的含义 */
 /* 此宏用于对齐和不对齐8字节边界上的堆栈以符合ABI */
 /* macros to align and unalign the stack on 8 byte boundary for ABI compliance */
-.macro STACK_ALIGN, reg /* 汇编带参数的宏定义*/ 
-    MOV     \reg, sp
+.macro STACK_ALIGN, reg /* 栈对齐*/ 
+    MOV     \reg, sp 
     TST     SP, #4
     SUBEQ   SP, #4
     PUSH    { \reg }
 .endm
 
-.macro STACK_RESTORE, reg /*汇编带参数的宏定义*/ 
-    POP     { \reg } @
-    MOV     sp, \reg
+.macro STACK_RESTORE, reg /*栈恢复*/ 
+    POP     { \reg } 
+    MOV     sp, \reg 
 .endm
-
-/* macros to save and restore fpu regs */
-.macro PUSH_FPU_REGS reg1 /* 汇编宏定义,类似于 #define PUSH_FPU_REGS(reg1) ... */ 
-#if !defined(LOSCFG_ARCH_FPU_DISABLE)
+/* FPU(floating-point processor unit)浮点运算单元*/
+/* macros to save and restore fpu regs */ 
+.macro PUSH_FPU_REGS reg1 /* 保存fpu寄存器 */ 
+#if !defined(LOSCFG_ARCH_FPU_DISABLE) @FPU使能
     VMRS    \reg1, FPEXC
     PUSH    {\reg1}
     VMRS    \reg1, FPSCR
@@ -75,7 +75,7 @@
 #endif
 .endm
 
-.macro POP_FPU_REGS reg1
+.macro POP_FPU_REGS reg1 /* 恢复fpu寄存器 */ 
 #if !defined(LOSCFG_ARCH_FPU_DISABLE)
     VPOP    {D0-D15}
 #if defined(LOSCFG_ARCH_FPU_VFP_D32)
@@ -94,12 +94,12 @@ OsStartToRun:
     MSR     CPSR_c, #(CPSR_INT_DISABLE | CPSR_SVC_MODE)  @禁止中断并切到管理模式
 
     LDRH    R1, [R0, #4] 	@将存储器地址为R0+4 的低16位数据读入寄存器R1，并将R1 的高16 位清零
-    ORR     R1, #OS_TASK_STATUS_RUNNING
-    STRH    R1, [R0, #4]
+    ORR     R1, #OS_TASK_STATUS_RUNNING @或指令 R1=R1|OS_TASK_STATUS_RUNNING
+    STRH    R1, [R0, #4] 	@将寄存器R1中的低16位写入以R0+4地址的存储器中
 
     /* R0 is new task, save it on tpidrprw */
-    MCR     p15, 0, R0, c13, c0, 4
-    ISB
+    MCR     p15, 0, R0, c13, c0, 4 @ C5=C4=R0
+    ISB 	@指令同步屏障，清除流水线并且确保在新指令执行时，之前的指令都已经执行完毕。
 
     VPUSH   {S0}                                     /* fpu */
     VPOP    {S0}
@@ -149,15 +149,15 @@ OsTaskContextLoad:
     MOV     R4, R0	@R4=R0 说明R4也记录了CPSR内容,这个内容将用于 OsKernelTaskLoad中保存到SPSR 
     AND     R0, R0, #CPSR_MASK_MODE @R0 =R0&CPSR_MASK_MODE ,目的是清除高16位
     CMP     R0, #CPSR_USER_MODE @比较R0是否为用户模式
-    BNE     OsKernelTaskLoad @不相等则跳转到OsKernelTaskLoad执行
+    BNE     OsKernelTaskLoad @不相等则跳转到OsKernelTaskLoad执行,return回去了
 
 #ifdef LOSCFG_KERNEL_SMP
 #ifdef LOSCFG_KERNEL_SMP_LOCKDEP
     /* 8 bytes stack align */
-    SUB     SP, SP, #4
-    LDR     R0, =g_taskSpin
-    BL      OsLockDepCheckOut
-    ADD     SP, SP, #4
+    SUB     SP, SP, #4 @sp = sp -4
+    LDR     R0, =g_taskSpin @R0 = g_taskSpin
+    BL      OsLockDepCheckOut @带链接的跳转指令。指令将下一条指令的地址拷贝到R14(即LR)链接寄存器中，然后跳转到指定地址运行程序
+    ADD     SP, SP, #4 @sp=sp+4
 #endif
     /* R0 = &g_taskSpin.rawLock */
     LDR     R0, =g_taskSpin
@@ -181,12 +181,12 @@ OsTaskContextLoad:
     ADD     SP, SP, #(2 * 4)
     LDMFD   SP!, {PC}^
 
-OsKernelTaskLoad: @内核任务的加载
-    MSR     SPSR_cxsf, R4 @将R4保存到程序状态保存寄存器32位
+OsKernelTaskLoad: 			@内核任务的加载
+    MSR     SPSR_cxsf, R4 	@将R4保存到程序状态保存寄存器32位
     /* restore r0-r12, lr */
-    LDMFD   SP!, {R0-R12} @出栈,依次保存到 R0-R12,其实就是恢复现场
-    ADD     SP, SP, #4 @sp=SP+4
-    LDMFD   SP!, {LR, PC}^ @返回地址赋给pc指针
+    LDMFD   SP!, {R0-R12} 	@出栈,依次保存到 R0-R12,其实就是恢复现场
+    ADD     SP, SP, #4 		@sp=SP+4
+    LDMFD   SP!, {LR, PC}^ 	@返回地址赋给pc指针
 
 OsIrqHandler:
     SUB     LR, LR, #4

arch/arm/arm/src/los_exc.c

@@ -285,14 +285,14 @@ STATIC VOID OsExcType(UINT32 excType, ExcContext *excBufAddr, UINT32 far, UINT32
 }
 
 STATIC const CHAR *g_excTypeString[] = {//异常类型的字符说明,在鸿蒙内核中什么才算是异常? 看这里
-    "reset",		//重置命令
-    "undefined instruction",	//未定义的指令
-    "software interrupt",	//软中断,比如定时器
-    "prefetch abort",	//取指异常
-    "data abort",		//数据异常
-    "fiq",				//快中断异常
-    "address abort",	//地址异常
-    "irq"				//中断异常
+    "reset",					//复位异常源    - SVC模式（Supervisor保护模式）
+    "undefined instruction",	//未定义指令异常源- und模式    
+    "software interrupt",		//软中断异常源 - SVC模式 
+    "prefetch abort",			//取指异常源 - abort模式	
+    "data abort",				//数据异常源 - abort模式
+    "fiq",						//快中断异常源 - FIQ模式  
+    "address abort",			//地址异常源 - abort模式
+    "irq"						//中断异常源 - IRQ模式 
 };
 //打印系统信息
 STATIC VOID OsExcSysInfo(UINT32 excType, const ExcContext *excBufAddr)
@@ -705,7 +705,7 @@ VOID BackTrace(UINT32 regFP)//fp:R11寄存器
 
     BackTraceSub(regFP);
 }
-//异常处理模块的初始化
+//异常接管模块的初始化
 VOID OsExcInit(VOID)
 {
     OsExcStackInfoReg(g_excStack, sizeof(g_excStack) / sizeof(g_excStack[0]));//异常模式下注册内核栈信息

arch/arm/arm/src/startup/reset_vector_up.S

@@ -36,6 +36,10 @@
 #include "los_mmu_descriptor_v6.h"
 #undef ASSEMBLY
 
+/******************************************************************************
+单CPU下异常向量表
+
+******************************************************************************/
 
     .global __exc_stack_top
     .global __irq_stack_top
@@ -68,16 +72,16 @@
 
     .fpu vfpv4
     .arm
-
+/* 设置异常模式栈的SP 参数1为栈底, 参数2为栈大小 r11 存放的是 cpu id */
 /* param0 is stack bottom, param1 is stack size, r11 hold cpu id */
 .macro EXC_SP_SET param0, param1
-    ldr    r1, =\param0
-    mov    r0, \param1
-    bl     sp_set
+    ldr    r1, =\param0 @r1 = 栈底
+    mov    r0, \param1 @r0 = 栈大小
+    bl     sp_set @跳到设置SP处
 .endm
 
 /* param0 is stack top, param1 is stack size, param2 is magic num */
-.macro STACK_MAGIC_SET param0, param1, param2
+.macro STACK_MAGIC_SET param0, param1, param2 @设置栈魔法数字
     ldr     r0, =\param0
     mov     r1, \param1
     ldr     r2, =\param2
@@ -332,12 +336,12 @@ cpu_start:	/* 启动CPU */
 /*
  * set sp for current cpu
  * r1 is stack bottom, r0 is stack size, r11 hold cpu id
- */
+ */@设置当前CPU的SP, r1为栈底, r0为栈大小 r11 为 cpu id
 sp_set:
-    mul    r3, r0, r11
-    sub    r2, r1, r3
-    mov    sp, r2
-    bx     lr          /* set sp */
+    mul    r3, r0, r11 	@r3=r0*r11 先计算偏移量
+    sub    r2, r1, r3 	@r2=r1-r3 如此得到r2为cpu的SP位置,从这里可以看出 栈底地址是要高于栈顶的
+    mov    sp, r2 		@sp = r2 设置栈指针位置,SP默认指向了栈底
+    bx     lr          /* set sp */ @跳回去继续执行
 
 /*
  * r4: page table base address
@@ -468,6 +472,6 @@ __svc_stack:
     .space OS_EXC_SVC_STACK_SIZE * CORE_NUM
 __svc_stack_top:
 
-__exc_stack:
+__exc_stack: 
     .space OS_EXC_STACK_SIZE * CORE_NUM
 __exc_stack_top:

kernel/base/misc/los_stackinfo.c

-/*
- * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
- * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this list of
- *    conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice, this list
- *    of conditions and the following disclaimer in the documentation and/or other materials
- *    provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its contributors may be used
- *    to endorse or promote products derived from this software without specific prior written
- *    permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "los_stackinfo_pri.h"
-#include "los_printf_pri.h"
-#include "los_config.h"
-#ifdef LOSCFG_SHELL
-#include "shcmd.h"
-#include "shell.h"
-#endif
-
-const StackInfo *g_stackInfo = NULL;
-UINT32 g_stackNum;
-//获取栈的吃水线
-UINT32 OsStackWaterLineGet(const UINTPTR *stackBottom, const UINTPTR *stackTop, UINT32 *peakUsed)
-{
-    UINT32 size;
-    const UINTPTR *tmp = NULL;
-    if (*stackTop == OS_STACK_MAGIC_WORD) {//栈顶值是否等于 magic 0xCCCCCCCC
-        tmp = stackTop + 1;
-        while ((tmp < stackBottom) && (*tmp == OS_STACK_INIT)) {//记录从栈顶到栈低有多少个连续的 0xCACACACA
-            tmp++;
-        }
-        size = (UINT32)((UINTPTR)stackBottom - (UINTPTR)tmp);//剩余多少非0xCACACACA的栈空间
-        *peakUsed = (size == 0) ? size : (size + sizeof(CHAR *));//得出高峰用值,还剩多少可用
-        return LOS_OK;
-    } else {
-        *peakUsed = OS_INVALID_WATERLINE;//栈溢出了
-        return LOS_NOK;
-    }
-}
-//异常情况下的栈检查,主要就是检查栈顶值有没有被改写
-VOID OsExcStackCheck(VOID)
-{
-    UINT32 index;
-    UINT32 cpuid;
-    UINTPTR *stackTop = NULL;
-
-    if (g_stackInfo == NULL) {
-        return;
-    }
-    for (index = 0; index < g_stackNum; index++) {
-        for (cpuid = 0; cpuid < LOSCFG_KERNEL_CORE_NUM; cpuid++) {
-            stackTop = (UINTPTR *)((UINTPTR)g_stackInfo[index].stackTop + cpuid * g_stackInfo[index].stackSize);
-            if (*stackTop != OS_STACK_MAGIC_WORD) {// 只要栈顶内容不是 0xCCCCCCCCC 就是溢出了. 
-                PRINT_ERR("cpu:%u %s overflow , magic word changed to 0x%x\n",
-                          LOSCFG_KERNEL_CORE_NUM - 1 - cpuid, g_stackInfo[index].stackName, *stackTop);
-            }
-        }
-    }
-}
-//打印栈的信息 把每个CPU的栈信息打印出来
-VOID OsExcStackInfo(VOID)
-{
-    UINT32 index;
-    UINT32 cpuid;
-    UINT32 size;
-    UINTPTR *stackTop = NULL;
-    UINTPTR *stack = NULL;
-
-    if (g_stackInfo == NULL) {
-        return;
-    }
-
-    PrintExcInfo("\n stack name    cpu id     stack addr     total size   used size\n"
-                 " ----------    ------     ---------      --------     --------\n");
-    for (index = 0; index < g_stackNum; index++) {
-        for (cpuid = 0; cpuid < LOSCFG_KERNEL_CORE_NUM; cpuid++) {//可以看出 各个CPU的栈是紧挨的的
-            stackTop = (UINTPTR *)((UINTPTR)g_stackInfo[index].stackTop + cpuid * g_stackInfo[index].stackSize);
-            stack = (UINTPTR *)((UINTPTR)stackTop + g_stackInfo[index].stackSize);
-            (VOID)OsStackWaterLineGet(stack, stackTop, &size);//获取吃水线, 鸿蒙用WaterLine 这个词用的很妙
-
-            PrintExcInfo("%11s      %-5d    %-10p     0x%-8x   0x%-4x\n", g_stackInfo[index].stackName,
-                         LOSCFG_KERNEL_CORE_NUM - 1 - cpuid, stackTop, g_stackInfo[index].stackSize, size);
-        }
-    }
-
-    OsExcStackCheck();//发生异常时栈检查
-}
-/*************************************************************************************** @note_pic
-  OsExcStackInfo 各个CPU栈布局图,其他栈也是一样,CPU各核硬件栈都是紧挨着
-  __undef_stack(SMP)
-+-------------------+ <--- cpu1 top
-|                   |
-|  CPU core1        |
-|                   |
-+--------------------<--- cpu2 top
-|                   |
-|  cpu core 2       |
-|                   |
-+--------------------<--- cpu3 top
-|                   |
-|  cpu core 3       |
-|                   |
-+--------------------<--- cpu4 top
-|                   |
-|  cpu core 4       |
-|                   |
-+-------------------+
-******************************************************************************************/
-
-//注册栈信息
-VOID OsExcStackInfoReg(const StackInfo *stackInfo, UINT32 stackNum)
-{
-    g_stackInfo = stackInfo;	//g_excStack
-    g_stackNum = stackNum;
-}
-//task栈的初始化,设置固定的值. 0xcccccccc 和 0xcacacaca
-VOID OsStackInit(VOID *stacktop, UINT32 stacksize)
-{
-    /* initialize the task stack, write magic num to stack top */
-    (VOID)memset_s(stacktop, stacksize, (INT32)OS_STACK_INIT, stacksize);//清一色填 0xCACACACA
-    *((UINTPTR *)stacktop) = OS_STACK_MAGIC_WORD;//0xCCCCCCCCC 中文就是"烫烫烫烫" 这几个字懂点计算机的人都不会陌生了.
-}
-
-#ifdef LOSCFG_SHELL_CMD_DEBUG
-SHELLCMD_ENTRY(stack_shellcmd, CMD_TYPE_EX, "stack", 1, (CmdCallBackFunc)OsExcStackInfo);//采用shell命令静态注册方式
-#endif
+/*
+ * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
+ * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ *    conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *    of conditions and the following disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used
+ *    to endorse or promote products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "los_stackinfo_pri.h"
+#include "los_printf_pri.h"
+#include "los_config.h"
+#ifdef LOSCFG_SHELL
+#include "shcmd.h"
+#include "shell.h"
+#endif
+
+const StackInfo *g_stackInfo = NULL;    //CPU所有工作模式的栈信息
+UINT32 g_stackNum;  //CPU所有工作模式的栈数量
+//获取栈的吃水线
+UINT32 OsStackWaterLineGet(const UINTPTR *stackBottom, const UINTPTR *stackTop, UINT32 *peakUsed)
+{
+    UINT32 size;
+    const UINTPTR *tmp = NULL;
+    if (*stackTop == OS_STACK_MAGIC_WORD) {//栈顶值是否等于 magic 0xCCCCCCCC
+        tmp = stackTop + 1;
+        while ((tmp < stackBottom) && (*tmp == OS_STACK_INIT)) {//记录从栈顶到栈低有多少个连续的 0xCACACACA
+            tmp++;
+        }
+        size = (UINT32)((UINTPTR)stackBottom - (UINTPTR)tmp);//剩余多少非0xCACACACA的栈空间
+        *peakUsed = (size == 0) ? size : (size + sizeof(CHAR *));//得出高峰用值,还剩多少可用
+        return LOS_OK;
+    } else {
+        *peakUsed = OS_INVALID_WATERLINE;//栈溢出了
+        return LOS_NOK;
+    }
+}
+//异常情况下的栈检查,主要就是检查栈顶值有没有被改写
+VOID OsExcStackCheck(VOID)
+{
+    UINT32 index;
+    UINT32 cpuid;
+    UINTPTR *stackTop = NULL;
+
+    if (g_stackInfo == NULL) {
+        return;
+    }
+    for (index = 0; index < g_stackNum; index++) {
+        for (cpuid = 0; cpuid < LOSCFG_KERNEL_CORE_NUM; cpuid++) {
+            stackTop = (UINTPTR *)((UINTPTR)g_stackInfo[index].stackTop + cpuid * g_stackInfo[index].stackSize);
+            if (*stackTop != OS_STACK_MAGIC_WORD) {// 只要栈顶内容不是 0xCCCCCCCCC 就是溢出了. 
+                PRINT_ERR("cpu:%u %s overflow , magic word changed to 0x%x\n",
+                          LOSCFG_KERNEL_CORE_NUM - 1 - cpuid, g_stackInfo[index].stackName, *stackTop);
+            }
+        }
+    }
+}
+//打印栈的信息 把每个CPU的栈信息打印出来
+VOID OsExcStackInfo(VOID)
+{
+    UINT32 index;
+    UINT32 cpuid;
+    UINT32 size;
+    UINTPTR *stackTop = NULL;
+    UINTPTR *stack = NULL;
+
+    if (g_stackInfo == NULL) {
+        return;
+    }
+
+    PrintExcInfo("\n stack name    cpu id     stack addr     total size   used size\n"
+                 " ----------    ------     ---------      --------     --------\n");
+    for (index = 0; index < g_stackNum; index++) {
+        for (cpuid = 0; cpuid < LOSCFG_KERNEL_CORE_NUM; cpuid++) {//可以看出 各个CPU的栈是紧挨的的
+            stackTop = (UINTPTR *)((UINTPTR)g_stackInfo[index].stackTop + cpuid * g_stackInfo[index].stackSize);
+            stack = (UINTPTR *)((UINTPTR)stackTop + g_stackInfo[index].stackSize);
+            (VOID)OsStackWaterLineGet(stack, stackTop, &size);//获取吃水线, 鸿蒙用WaterLine 这个词用的很妙
+
+            PrintExcInfo("%11s      %-5d    %-10p     0x%-8x   0x%-4x\n", g_stackInfo[index].stackName,
+                         LOSCFG_KERNEL_CORE_NUM - 1 - cpuid, stackTop, g_stackInfo[index].stackSize, size);
+        }
+    }
+
+    OsExcStackCheck();//发生异常时栈检查
+}
+/*************************************************************************************** @note_pic
+  OsExcStackInfo 各个CPU栈布局图,其他栈也是一样,CPU各核硬件栈都是紧挨着
+  __undef_stack(SMP)
++-------------------+ <--- cpu1 top
+|                   |
+|  CPU core1        |
+|                   |
++--------------------<--- cpu2 top
+|                   |
+|  cpu core 2       |
+|                   |
++--------------------<--- cpu3 top
+|                   |
+|  cpu core 3       |
+|                   |
++--------------------<--- cpu4 top
+|                   |
+|  cpu core 4       |
+|                   |
++-------------------+
+******************************************************************************************/
+
+//注册栈信息
+VOID OsExcStackInfoReg(const StackInfo *stackInfo, UINT32 stackNum)
+{
+    g_stackInfo = stackInfo;	//全局变量指向g_excStack
+    g_stackNum = stackNum;
+}
+//task栈的初始化,设置固定的值. 0xcccccccc 和 0xcacacaca
+VOID OsStackInit(VOID *stacktop, UINT32 stacksize)
+{
+    /* initialize the task stack, write magic num to stack top */
+    (VOID)memset_s(stacktop, stacksize, (INT32)OS_STACK_INIT, stacksize);//清一色填 0xCACACACA
+    *((UINTPTR *)stacktop) = OS_STACK_MAGIC_WORD;//0xCCCCCCCCC 中文就是"烫烫烫烫" 这几个字懂点计算机的人都不会陌生了.
+}
+
+#ifdef LOSCFG_SHELL_CMD_DEBUG
+SHELLCMD_ENTRY(stack_shellcmd, CMD_TYPE_EX, "stack", 1, (CmdCallBackFunc)OsExcStackInfo);//采用shell命令静态注册方式
+#endif

zzz/git/push.sh

 git add -A
-git commit -m  '注解汇编代码,原来它们竟如此可爱,爱了爱了.
+git commit -m  'CPU有哪几种工作模式?每种模式都有独立堆栈,如何用汇编初始化这些栈?
     搜索 @note_pic 可查看绘制的全部字符图
     搜索 @note_why 是尚未看明白的地方，有看明白的，请Pull Request完善
     搜索 @note_thinking 是一些的思考和建议