初始化硬时钟.

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

初始化硬时钟.
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
0265a1ff · 鸿蒙内核源码分析 · f9551571 · 0265a1ff · 0265a1ff · 0265a1ff
8 changed file
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@

 [![star](https://gitee.com/weharmony/kernel_liteos_a_note/badge/star.svg?theme=dark)](https://gitee.com/weharmony/kernel_liteos_a_note)[![fork](https://gitee.com/weharmony/kernel_liteos_a_note/badge/fork.svg?theme=dark)](https://gitee.com/weharmony/kernel_liteos_a_note)

-每个码农,学职生涯,都应精读一遍内核源码.精读内核源码最大的好处是:将孤立知识点织成一张高浓度,高密度底层网,是对计算机底层体系化理解形成永久记忆
+每个码农,学职生涯,都应精读一遍内核源码.是浇筑计算机知识大厦的地基工程，地基纵深坚固程度，决定了大厦能盖多高。为何一定要精读?因为内核代码本身并不太多，都是浓缩的精华，精读就是让各个知识点高频出现，闪爆大脑，短时间内容易结成一张高浓度，高密度的底层网，形成永久大脑记忆。跟骑单车一样，一旦学会，即便多年不骑，照样跨上就走，游刃有余。

 ## **做了些什么呢？**

@@ -61,17 +61,15 @@
    第二: **专业概念抽象级** 对抽象的专业逻辑概念具体化认知, 比如虚拟内存,老百姓是听不懂的,学过计算机的人都懂,具体怎么实现的很多人又都不懂了,但这并不妨碍成为一个优秀的上层应用程序员,因为虚拟内存已经被抽象出来,目的是要屏蔽上层对它的现实认知.试图用 **[鸿蒙源码分析系列篇 【 CSDN](https://blog.csdn.net/kuangyufei/article/details/108727970) [| OSCHINA](https://my.oschina.net/u/3751245/blog/4626852) [| WIKI 】](https://gitee.com/weharmony/kernel_liteos_a_note/wikis/pages)** 去拆解那些已经被抽象出来的专业概念, 希望能卷入更多对内核感兴趣的应用软件人才流入基础软件生态, 应用软件咱们是无敌宇宙,但基础软件却很薄弱.
    
    第三: **具体微观代码级** 这一级是具体到每一行代码的实现,到了用代码指令级的地步,这段代码是什么意思?为什么要这么设计? **[kernel\_liteos\_a_note:鸿蒙内核源码注释中文版](https://gitee.com/weharmony/kernel_liteos_a_note)** 试图从细微处去解释代码实现层,英文真的是天生适合设计成编程语言的人类语言,计算机的01码映射到人类世界的26个字母,诞生了太多的伟大奇迹.但我们的母语注定了很大部分人存在着自然语言层级的理解映射,希望注释中文版能让更多爱好者快速的理解内核,共同进步.
-
-   ### **鸿蒙内核500问，你知道多少？**
-
-    抛出的500个内核知识问题,可前往 **[鸿蒙内核源码分析(源码结构篇) | 内核500问 【 CSDN ](https://blog.csdn.net/kuangyufei/article/details/111938348) [| OSCHINA 】](https://my.oschina.net/u/3751245/blog/4869137)** 查看.   
    
 -   ### **系列博客更新到哪里了？**

-    把研究过程心得写成鸿蒙源码分析系列篇,如此源码中文注释+系列篇文章,将加速理解鸿蒙内核实现过程,因时间有限,博文更新较慢,会反复修正.
+    把研究过程心得写成鸿蒙源码分析系列篇,如此源码中文注释+系列篇文章,将加速理解鸿蒙内核实现过程.

    - **[鸿蒙源码分析系列(总目录) | 持续更新中... 【 CSDN ](https://blog.csdn.net/kuangyufei/article/details/108727970) [| OSCHINA 】](https://my.oschina.net/u/3751245/blog/4626852)**

+        * **[|-  鸿蒙内核源码分析(位图管理篇) | 为何进程和线程都是32个优先级？ 【 CSDN ](https://blog.csdn.net/kuangyufei/article/details/112394982) [| OSCHINA 】](https://my.oschina.net/u/3751245/blog/4888467)**
+
        * **[|-  鸿蒙内核源码分析(源码结构篇) | 内核500问你能答对多少？ 【 CSDN ](https://blog.csdn.net/kuangyufei/article/details/111938348) [| OSCHINA 】](https://my.oschina.net/u/3751245/blog/4869137)**

        * **[|-  鸿蒙内核源码分析(物理内存篇) | 伙伴算法是在卖标准猪肉块吗？【 CSDN ](https://blog.csdn.net/kuangyufei/article/details/111765600) [| OSCHINA 】](https://my.oschina.net/u/3751245/blog/4842408)**
@@ -117,12 +115,10 @@

    2. [新建 Issue](https://gitee.com/weharmony/kernel_liteos_a_note/issues)

-   ### **鸿蒙内核源码分析 官方公众号**
+-   ### **喜欢关注官方公众号**

    ![在这里插入图片描述](./zzz/pic/other/wxcode.png)

-    感谢关注,您的支持是注者最大的动力. 
-
    作者邮箱:weharmony@126.com

    ---

--- a/kernel/base/core/los_process.c
+++ b/kernel/base/core/los_process.c
@@ -125,7 +125,7 @@ LITE_OS_SEC_TEXT_INIT VOID OsTaskSchedQueueEnqueue(LosTaskCB *taskCB, UINT16 sta
    LOS_ASSERT(!(taskCB->taskStatus & OS_TASK_STATUS_READY));// 只有非就绪状态任务才能入队
 	
    processCB = OS_PCB_FROM_PID(taskCB->processID);// 通过一个任务得到这个任务所在的进程
-    if (!(processCB->processStatus & OS_PROCESS_STATUS_READY)) {//task状态为就绪状态
+    if (!(processCB->processStatus & OS_PROCESS_STATUS_READY)) {//task状态没有就绪状态标签
        if (((processCB->policy == LOS_SCHED_RR) && (processCB->timeSlice != 0)) ||//调度方式为抢断且时间片没用完
            ((processCB->processStatus & OS_PROCESS_STATUS_RUNNING) && (processCB->policy == LOS_SCHED_FIFO))) {//或处于运行的FIFO调度方式的task
            OS_PROCESS_PRI_QUEUE_ENQUEUE_HEAD(processCB);//进程入g_priQueueList就绪队列头部
@@ -139,7 +139,7 @@ LITE_OS_SEC_TEXT_INIT VOID OsTaskSchedQueueEnqueue(LosTaskCB *taskCB, UINT16 sta
        LOS_ASSERT((UINTPTR)processCB->pendList.pstNext);
        if ((processCB->timeSlice == 0) && (processCB->policy == LOS_SCHED_RR)) {//没有时间片且采用抢占式调度算法的情况
            OS_PROCESS_PRI_QUEUE_DEQUEUE(processCB);//进程先出队列
-            OS_PROCESS_PRI_QUEUE_ENQUEUE(processCB);//进程再入队列,区别是排到了最后.这可是队列前面还有很多人等着被调度呢.
+            OS_PROCESS_PRI_QUEUE_ENQUEUE(processCB);//进程再入队列,区别是排到了最后.队列前面还有很多进程在等着被调度.
        }
    }

@@ -362,29 +362,29 @@ STATIC VOID OsWaitCheckAndWakeParentProcess(LosProcessCB *parentCB, const LosPro

    return;
 }
-
+//回收指定进程的资源
 LITE_OS_SEC_TEXT VOID OsProcessResourcesToFree(LosProcessCB *processCB)
 {
-    if (!(processCB->processStatus & (OS_PROCESS_STATUS_INIT | OS_PROCESS_STATUS_RUNNING))) {
-        PRINT_ERR("The process(%d) has no permission to release process(%d) resources!\n",
+    if (!(processCB->processStatus & (OS_PROCESS_STATUS_INIT | OS_PROCESS_STATUS_RUNNING))) {//1.初始化阶段并没有使用到资源,所以不用回收
+        PRINT_ERR("The process(%d) has no permission to release process(%d) resources!\n",//2.正在运行的进程不能回收
                  OsCurrProcessGet()->processID, processCB->processID);
    }

 #ifdef LOSCFG_FS_VFS
-    if (OsProcessIsUserMode(processCB)) {//用户模式下
-        delete_files(processCB, processCB->files);//删除文件
+    if (OsProcessIsUserMode(processCB)) {//用户进程
+        delete_files(processCB, processCB->files);//删除与用户进程相关的文件
    }
    processCB->files = NULL;
 #endif

-#ifdef LOSCFG_SECURITY_CAPABILITY
+#ifdef LOSCFG_SECURITY_CAPABILITY //安全开关
    if (processCB->user != NULL) {
-        (VOID)LOS_MemFree(m_aucSysMem1, processCB->user);
+        (VOID)LOS_MemFree(m_aucSysMem1, processCB->user);//删除用户
        processCB->user = NULL;
    }
 #endif

-    OsSwtmrRecycle(processCB->processID);//软件定时器回收
+    OsSwtmrRecycle(processCB->processID);//回收进程使用的定时器
    processCB->timerID = (timer_t)(UINTPTR)MAX_INVALID_TIMER_VID;

 #ifdef LOSCFG_SECURITY_VID
@@ -395,13 +395,13 @@ LITE_OS_SEC_TEXT VOID OsProcessResourcesToFree(LosProcessCB *processCB)
 #endif

 #if (LOSCFG_KERNEL_LITEIPC == YES)
-    if (OsProcessIsUserMode(processCB)) {//用户模式下
-        LiteIpcPoolDelete(&(processCB->ipcInfo));//删除进程IPC
+    if (OsProcessIsUserMode(processCB)) {//用户进程
+        LiteIpcPoolDelete(&(processCB->ipcInfo));//删除进程对lite IPC的开销
        (VOID)memset_s(&(processCB->ipcInfo), sizeof(ProcIpcInfo), 0, sizeof(ProcIpcInfo));
    }
 #endif
 }
-//回收僵死状态进程流程
+//回收僵死状态进程的资源
 LITE_OS_SEC_TEXT STATIC VOID OsRecycleZombiesProcess(LosProcessCB *childCB, ProcessGroup **group)
 {
    OsExitProcessGroup(childCB, group);//退出进程组
@@ -420,7 +420,7 @@ LITE_OS_SEC_TEXT STATIC VOID OsRecycleZombiesProcess(LosProcessCB *childCB, Proc
        OsInsertPCBToFreeList(childCB);//直接插到freeList中去，可用于重新分配了。
    }
 }
-
+//当一个进程自然退出的时候,它的孩子进程要怎么处理
 STATIC VOID OsDealAliveChildProcess(LosProcessCB *processCB)
 {
    UINT32 parentID;
@@ -429,13 +429,13 @@ STATIC VOID OsDealAliveChildProcess(LosProcessCB *processCB)
    LOS_DL_LIST *nextList = NULL;
    LOS_DL_LIST *childHead = NULL;

-    if (!LOS_ListEmpty(&processCB->childrenList)) {
+    if (!LOS_ListEmpty(&processCB->childrenList)) {//如果存在孩子进程
        childHead = processCB->childrenList.pstNext;
        LOS_ListDelete(&(processCB->childrenList));
-        if (OsProcessIsUserMode(processCB)) {
-            parentID = g_userInitProcess;
+        if (OsProcessIsUserMode(processCB)) {//是用户模式吗?
+            parentID = g_userInitProcess;//指定1号进程父ID
        } else {
-            parentID = g_kernelInitProcess;
+            parentID = g_kernelInitProcess;//指定2号进程为父ID
        }

        for (nextList = childHead; ;) {
@@ -474,9 +474,9 @@ STATIC VOID OsProcessNaturalExit(LosTaskCB *runTask, UINT32 status)
    LOS_ASSERT(!(processCB->threadScheduleMap != 0));//断言没有任务需要调度了,当前task是最后一个了
    LOS_ASSERT(processCB->processStatus & OS_PROCESS_STATUS_RUNNING);//断言必须为正在运行的进程

-    OsChildProcessResourcesFree(processCB);//
+    OsChildProcessResourcesFree(processCB);//释放孩子进程的资源

-#ifdef LOSCFG_KERNEL_CPUP
+#ifdef LOSCFG_KERNEL_CPUP 
    OsCpupClean(processCB->processID);
 #endif

@@ -495,7 +495,7 @@ STATIC VOID OsProcessNaturalExit(LosTaskCB *runTask, UINT32 status)

        OsDealAliveChildProcess(processCB);

-        processCB->processStatus |= OS_PROCESS_STATUS_ZOMBIES;
+        processCB->processStatus |= OS_PROCESS_STATUS_ZOMBIES;//贴上僵死进程的标签

        (VOID)OsKill(processCB->parentProcessID, SIGCHLD, OS_KERNEL_KILL_PERMISSION);
        LOS_ListHeadInsert(&g_processRecyleList, &processCB->pendList);
@@ -526,10 +526,10 @@ LITE_OS_SEC_TEXT_INIT UINT32 OsProcessInit(VOID)

    for (index = 0; index < g_processMaxNum; index++) {//进程池循环创建
        g_processCBArray[index].processID = index;//进程ID[0-g_processMaxNum]赋值
-        g_processCBArray[index].processStatus = OS_PROCESS_FLAG_UNUSED;// 默认都是白纸一张，臣妾干净着呢
+        g_processCBArray[index].processStatus = OS_PROCESS_FLAG_UNUSED;// 默认都是白纸一张,贴上未使用标签
        LOS_ListTailInsert(&g_freeProcess, &g_processCBArray[index].pendList);//注意g_freeProcess挂的是pendList节点,所以使用要通过OS_PCB_FROM_PENDLIST找到进程实体.
    }
-	// ????? 为啥用户模式的根进程 选1 ,内核模式的根进程选2 
+
    g_userInitProcess = 1; /* 1: The root process ID of the user-mode process is fixed at 1 *///用户模式的根进程
    LOS_ListDelete(&g_processCBArray[g_userInitProcess].pendList);// 清空g_userInitProcess pend链表


--- a/kernel/base/core/los_tick.c
+++ b/kernel/base/core/los_tick.c
@@ -47,16 +47,16 @@ extern "C" {
 #endif /* __cplusplus */

 LITE_OS_SEC_BSS volatile UINT64 g_tickCount[LOSCFG_KERNEL_CORE_NUM] = {0};//tick计数器,系统一旦启动,一直在++, 为防止溢出,这是一个 UINT64 的变量
-LITE_OS_SEC_DATA_INIT UINT32 g_sysClock;//系统时钟
+LITE_OS_SEC_DATA_INIT UINT32 g_sysClock;//系统时钟,是绝大部分部件工作的时钟源，也是其他所有外设的时钟的来源 
 LITE_OS_SEC_DATA_INIT UINT32 g_tickPerSecond;//每秒Tick数,鸿蒙默认是每秒100次,即:10ms
-LITE_OS_SEC_BSS DOUBLE g_cycle2NsScale;
+LITE_OS_SEC_BSS DOUBLE g_cycle2NsScale;	//周期转纳秒级

 /* spinlock for task module */
 LITE_OS_SEC_BSS SPIN_LOCK_INIT(g_tickSpin); //节拍器自旋锁

 /*
 * Description : Tick interruption handler
- *///系统时钟中断处理函数 ,鸿蒙是 10ms触发一次
+ *///节拍中断处理函数 ,鸿蒙默认10ms触发一次
 LITE_OS_SEC_TEXT VOID OsTickHandler(VOID)
 {
    UINT32 intSave;

--- a/kernel/base/include/los_process_pri.h
+++ b/kernel/base/include/los_process_pri.h
@@ -314,9 +314,9 @@ STATIC INLINE BOOL OsProcessIsDead(const LosProcessCB *processCB)//查下进程
 #define OS_USER_TASK_SYSCALL_SATCK_SIZE 0x3000	//用户通过系统调用的栈大小 12K ,这时是运行在内核模式下
 #define OS_USER_TASK_STACK_SIZE         0x100000	//用户任务运行在用户空间的栈大小 1M 

-#define OS_KERNEL_MODE 0x0U	//内核态模式
-#define OS_USER_MODE   0x1U	//用户态模式
-STATIC INLINE BOOL OsProcessIsUserMode(const LosProcessCB *processCB)//进程处于用户态?
+#define OS_KERNEL_MODE 0x0U	//内核模式
+#define OS_USER_MODE   0x1U	//用户模式
+STATIC INLINE BOOL OsProcessIsUserMode(const LosProcessCB *processCB)//用户模式进程
 {
    return (processCB->processMode == OS_USER_MODE);
 }

--- a/platform/hw/arm/timer/arm_generic/arm_generic_timer.c
+++ b/platform/hw/arm/timer/arm_generic/arm_generic_timer.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_hw_pri.h"
-#include "los_tick_pri.h"
-#include "los_sys_pri.h"
-#include "gic_common.h"
-
-#define STRING_COMB(x, y, z)        x ## y ## z
-
-#ifdef LOSCFG_ARCH_SECURE_MONITOR_MODE
-#define TIMER_REG(reg)              STRING_COMB(TIMER_REG_, CNTPS, reg)
-#else
-#define TIMER_REG(reg)              STRING_COMB(TIMER_REG_, CNTP, reg)
-#endif
-#define TIMER_REG_CTL               TIMER_REG(_CTL)     /* 32 bits */
-#define TIMER_REG_TVAL              TIMER_REG(_TVAL)    /* 32 bits */
-#define TIMER_REG_CVAL              TIMER_REG(_CVAL)    /* 64 bits */
-#define TIMER_REG_CT                TIMER_REG(CT)       /* 64 bits */
-
-#ifdef __LP64__
-
-#define TIMER_REG_CNTFRQ            cntfrq_el0
-
-/* CNTP AArch64 registers */
-#define TIMER_REG_CNTP_CTL          cntp_ctl_el0
-#define TIMER_REG_CNTP_TVAL         cntp_tval_el0
-#define TIMER_REG_CNTP_CVAL         cntp_cval_el0
-#define TIMER_REG_CNTPCT            cntpct_el0
-
-/* CNTPS AArch64 registers */
-#define TIMER_REG_CNTPS_CTL         cntps_ctl_el1
-#define TIMER_REG_CNTPS_TVAL        cntps_tval_el1
-#define TIMER_REG_CNTPS_CVAL        cntps_cval_el1
-#define TIMER_REG_CNTPSCT           cntpct_el0
-
-#define READ_TIMER_REG32(reg)       AARCH64_SYSREG_READ(reg)
-#define READ_TIMER_REG64(reg)       AARCH64_SYSREG_READ(reg)
-#define WRITE_TIMER_REG32(reg, val) AARCH64_SYSREG_WRITE(reg, (UINT64)(val))
-#define WRITE_TIMER_REG64(reg, val) AARCH64_SYSREG_WRITE(reg, val)
-
-#else /* Aarch32 */
-
-#define TIMER_REG_CNTFRQ            CP15_REG(c14, 0, c0, 0)
-
-/* CNTP AArch32 registers */
-#define TIMER_REG_CNTP_CTL          CP15_REG(c14, 0, c2, 1)
-#define TIMER_REG_CNTP_TVAL         CP15_REG(c14, 0, c2, 0)
-#define TIMER_REG_CNTP_CVAL         CP15_REG64(c14, 2)
-#define TIMER_REG_CNTPCT            CP15_REG64(c14, 0)
-
-/* CNTPS AArch32 registers are banked and accessed though CNTP */
-#define CNTPS CNTP
-
-#define READ_TIMER_REG32(reg)       ARM_SYSREG_READ(reg)
-#define READ_TIMER_REG64(reg)       ARM_SYSREG64_READ(reg)
-#define WRITE_TIMER_REG32(reg, val) ARM_SYSREG_WRITE(reg, val)
-#define WRITE_TIMER_REG64(reg, val) ARM_SYSREG64_WRITE(reg, val)
-
-#endif
-
-#define OS_CYCLE_PER_TICK (g_sysClock / LOSCFG_BASE_CORE_TICK_PER_SECOND) //每个tick多少周期
-
-UINT32 HalClockFreqRead(VOID)
-{
-    return READ_TIMER_REG32(TIMER_REG_CNTFRQ);
-}
-
-VOID HalClockFreqWrite(UINT32 freq)
-{
-    WRITE_TIMER_REG32(TIMER_REG_CNTFRQ, freq);
-}
-
-STATIC_INLINE VOID TimerCtlWrite(UINT32 cntpCtl)
-{
-    WRITE_TIMER_REG32(TIMER_REG_CTL, cntpCtl);
-}
-
-STATIC_INLINE UINT64 TimerCvalRead(VOID)
-{
-    return READ_TIMER_REG64(TIMER_REG_CVAL);
-}
-
-STATIC_INLINE VOID TimerCvalWrite(UINT64 cval)
-{
-    WRITE_TIMER_REG64(TIMER_REG_CVAL, cval);
-}
-
-STATIC_INLINE VOID TimerTvalWrite(UINT32 tval)
-{
-    WRITE_TIMER_REG32(TIMER_REG_TVAL, tval);
-}
-
-UINT64 HalClockGetCycles(VOID)
-{
-    UINT64 cntpct;
-
-    cntpct = READ_TIMER_REG64(TIMER_REG_CT);
-    return cntpct;
-}
-//节拍回调函数
-LITE_OS_SEC_TEXT VOID OsTickEntry(VOID)
-{
-    TimerCtlWrite(0);
-
-    OsTickHandler();//节拍处理主体函数
-
-    /*	//使用最近的 cval生成下一个tick的计时是绝对和准确的。
-     * use last cval to generate the next tick's timing is
-     * absolute and accurate. DO NOT use tval to drive the
-     * generic time in which case tick will be slower.
-     *///不要使用tval来产生时间，在这种情况下，滴答声会变慢
-    TimerCvalWrite(TimerCvalRead() + OS_CYCLE_PER_TICK);
-    TimerCtlWrite(1);
-}
-
-LITE_OS_SEC_TEXT_INIT VOID HalClockInit(VOID)
-{
-    UINT32 ret;
-
-    g_sysClock = HalClockFreqRead();//读时间
-    ret = LOS_HwiCreate(OS_TICK_INT_NUM, MIN_INTERRUPT_PRIORITY, 0, OsTickEntry, 0);
-    if (ret != LOS_OK) {
-        PRINT_ERR("%s, %d create tick irq failed, ret:0x%x\n", __FUNCTION__, __LINE__, ret);
-    }
-}
-
-LITE_OS_SEC_TEXT_INIT VOID HalClockStart(VOID)
-{
-    HalIrqUnmask(OS_TICK_INT_NUM);
-
-    /* triggle the first tick */
-    TimerCtlWrite(0);
-    TimerTvalWrite(OS_CYCLE_PER_TICK);
-    TimerCtlWrite(1);
-}
-
-VOID HalDelayUs(UINT32 usecs)
-{
-    UINT64 cycles = (UINT64)usecs * HalClockFreqRead() / OS_SYS_US_PER_SECOND;
-    UINT64 deadline = HalClockGetCycles() + cycles;
-
-    while (HalClockGetCycles() < deadline) {
-        __asm__ volatile ("nop");
-    }
-}
-
-UINT64 hi_sched_clock(VOID)
-{
-    return LOS_CurrNanosec();
-}
-
-UINT32 HalClockGetTickTimerCycles(VOID)
-{
-    UINT64 cval = TimerCvalRead();
-    UINT64 cycles = HalClockGetCycles();
-
-    return (UINT32)((cval > cycles) ? (cval - cycles) : 0);
-}
-
-VOID HalClockTickTimerReload(UINT32 cycles)
-{
-    HalIrqMask(OS_TICK_INT_NUM);
-    HalIrqClear(OS_TICK_INT_NUM);
-
-    TimerCtlWrite(0);
-    TimerCvalWrite(HalClockGetCycles() + cycles);
-    TimerCtlWrite(1);
-
-    HalIrqUnmask(OS_TICK_INT_NUM);
-}
+/*
+ * 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_hw_pri.h"
+#include "los_tick_pri.h"
+#include "los_sys_pri.h"
+#include "gic_common.h"
+
+#define STRING_COMB(x, y, z)        x ## y ## z
+
+#ifdef LOSCFG_ARCH_SECURE_MONITOR_MODE
+#define TIMER_REG(reg)              STRING_COMB(TIMER_REG_, CNTPS, reg)
+#else
+#define TIMER_REG(reg)              STRING_COMB(TIMER_REG_, CNTP, reg)
+#endif
+#define TIMER_REG_CTL               TIMER_REG(_CTL)     /* 32 bits */
+#define TIMER_REG_TVAL              TIMER_REG(_TVAL)    /* 32 bits */
+#define TIMER_REG_CVAL              TIMER_REG(_CVAL)    /* 64 bits */
+#define TIMER_REG_CT                TIMER_REG(CT)       /* 64 bits */
+
+#ifdef __LP64__
+
+#define TIMER_REG_CNTFRQ            cntfrq_el0
+
+/* CNTP AArch64 registers */
+#define TIMER_REG_CNTP_CTL          cntp_ctl_el0
+#define TIMER_REG_CNTP_TVAL         cntp_tval_el0
+#define TIMER_REG_CNTP_CVAL         cntp_cval_el0
+#define TIMER_REG_CNTPCT            cntpct_el0
+
+/* CNTPS AArch64 registers */
+#define TIMER_REG_CNTPS_CTL         cntps_ctl_el1
+#define TIMER_REG_CNTPS_TVAL        cntps_tval_el1
+#define TIMER_REG_CNTPS_CVAL        cntps_cval_el1
+#define TIMER_REG_CNTPSCT           cntpct_el0
+
+#define READ_TIMER_REG32(reg)       AARCH64_SYSREG_READ(reg)
+#define READ_TIMER_REG64(reg)       AARCH64_SYSREG_READ(reg)
+#define WRITE_TIMER_REG32(reg, val) AARCH64_SYSREG_WRITE(reg, (UINT64)(val))
+#define WRITE_TIMER_REG64(reg, val) AARCH64_SYSREG_WRITE(reg, val)
+
+#else /* Aarch32 */
+
+#define TIMER_REG_CNTFRQ            CP15_REG(c14, 0, c0, 0)
+
+/* CNTP AArch32 registers */
+#define TIMER_REG_CNTP_CTL          CP15_REG(c14, 0, c2, 1)
+#define TIMER_REG_CNTP_TVAL         CP15_REG(c14, 0, c2, 0)
+#define TIMER_REG_CNTP_CVAL         CP15_REG64(c14, 2)
+#define TIMER_REG_CNTPCT            CP15_REG64(c14, 0)
+
+/* CNTPS AArch32 registers are banked and accessed though CNTP */
+#define CNTPS CNTP
+
+#define READ_TIMER_REG32(reg)       ARM_SYSREG_READ(reg)
+#define READ_TIMER_REG64(reg)       ARM_SYSREG64_READ(reg)
+#define WRITE_TIMER_REG32(reg, val) ARM_SYSREG_WRITE(reg, val)
+#define WRITE_TIMER_REG64(reg, val) ARM_SYSREG64_WRITE(reg, val)
+
+#endif
+
+#define OS_CYCLE_PER_TICK (g_sysClock / LOSCFG_BASE_CORE_TICK_PER_SECOND) //每个tick多少周期
+
+UINT32 HalClockFreqRead(VOID)
+{
+    return READ_TIMER_REG32(TIMER_REG_CNTFRQ);
+}
+
+VOID HalClockFreqWrite(UINT32 freq)
+{
+    WRITE_TIMER_REG32(TIMER_REG_CNTFRQ, freq);
+}
+//写时间控制寄存器
+STATIC_INLINE VOID TimerCtlWrite(UINT32 cntpCtl)
+{
+    WRITE_TIMER_REG32(TIMER_REG_CTL, cntpCtl);
+}
+
+STATIC_INLINE UINT64 TimerCvalRead(VOID)
+{
+    return READ_TIMER_REG64(TIMER_REG_CVAL);
+}
+
+STATIC_INLINE VOID TimerCvalWrite(UINT64 cval)
+{
+    WRITE_TIMER_REG64(TIMER_REG_CVAL, cval);
+}
+
+STATIC_INLINE VOID TimerTvalWrite(UINT32 tval)
+{
+    WRITE_TIMER_REG32(TIMER_REG_TVAL, tval);
+}
+
+UINT64 HalClockGetCycles(VOID)
+{
+    UINT64 cntpct;
+
+    cntpct = READ_TIMER_REG64(TIMER_REG_CT);
+    return cntpct;
+}
+//节拍回调函数
+LITE_OS_SEC_TEXT VOID OsTickEntry(VOID)
+{
+    TimerCtlWrite(0);
+
+    OsTickHandler();//节拍处理主体函数
+
+    /*	//使用最近的 cval生成下一个tick的计时是绝对和准确的。
+     * use last cval to generate the next tick's timing is
+     * absolute and accurate. DO NOT use tval to drive the
+     * generic time in which case tick will be slower.
+     *///不要使用tval来产生时间，在这种情况下，滴答声会变慢
+    TimerCvalWrite(TimerCvalRead() + OS_CYCLE_PER_TICK);
+    TimerCtlWrite(1);
+}
+
+LITE_OS_SEC_TEXT_INIT VOID HalClockInit(VOID)
+{
+    UINT32 ret;
+
+    g_sysClock = HalClockFreqRead();//读硬时钟频率
+    ret = LOS_HwiCreate(OS_TICK_INT_NUM, MIN_INTERRUPT_PRIORITY, 0, OsTickEntry, 0);//创建硬时钟中断
+    if (ret != LOS_OK) {//29号中断,暂时使用安全物理计时器
+        PRINT_ERR("%s, %d create tick irq failed, ret:0x%x\n", __FUNCTION__, __LINE__, ret);
+    }
+}
+
+LITE_OS_SEC_TEXT_INIT VOID HalClockStart(VOID)
+{
+    HalIrqUnmask(OS_TICK_INT_NUM);//取消屏蔽29号中断
+
+    /* triggle the first tick */
+    TimerCtlWrite(0);//
+    TimerTvalWrite(OS_CYCLE_PER_TICK);//设置节拍周期
+    TimerCtlWrite(1);
+}
+
+VOID HalDelayUs(UINT32 usecs)
+{
+    UINT64 cycles = (UINT64)usecs * HalClockFreqRead() / OS_SYS_US_PER_SECOND;
+    UINT64 deadline = HalClockGetCycles() + cycles;
+
+    while (HalClockGetCycles() < deadline) {
+        __asm__ volatile ("nop");
+    }
+}
+
+UINT64 hi_sched_clock(VOID)
+{
+    return LOS_CurrNanosec();
+}
+
+UINT32 HalClockGetTickTimerCycles(VOID)
+{
+    UINT64 cval = TimerCvalRead();
+    UINT64 cycles = HalClockGetCycles();
+
+    return (UINT32)((cval > cycles) ? (cval - cycles) : 0);
+}
+
+VOID HalClockTickTimerReload(UINT32 cycles)
+{
+    HalIrqMask(OS_TICK_INT_NUM);//先屏蔽时钟中断
+    HalIrqClear(OS_TICK_INT_NUM);//清除中断位
+
+    TimerCtlWrite(0);
+    TimerCvalWrite(HalClockGetCycles() + cycles);
+    TimerCtlWrite(1);
+
+    HalIrqUnmask(OS_TICK_INT_NUM);//取消屏蔽时钟中断
+}
--- a/platform/hw/arm/timer/arm_private/arm_private_timer.c
+++ b/platform/hw/arm/timer/arm_private/arm_private_timer.c
@@ -33,19 +33,19 @@
 #include "los_hwi.h"
 #include "los_tick_pri.h"

-#define OS_CYCLE_PER_TICK (TIMER_FREQ / LOSCFG_BASE_CORE_TICK_PER_SECOND)
+#define OS_CYCLE_PER_TICK (TIMER_FREQ / LOSCFG_BASE_CORE_TICK_PER_SECOND) 

 typedef struct {
-    UINT32 load;        /* Private Timer Load Register */
-    UINT32 count;       /* Private Timer Counter Register */
-    UINT32 control;     /* Private Timer Control Register */
-    UINT32 intStatus;   /* Private Timer Interrupt Status Register */
+    UINT32 load;        /* Private Timer Load Register */ //专用定时器加载寄存器
+    UINT32 count;       /* Private Timer Counter Register */ //专用定时器计数寄存器
+    UINT32 control;     /* Private Timer Control Register */ //专用定时器控制寄存器
+    UINT32 intStatus;   /* Private Timer Interrupt Status Register */ //专用定时器中断状态寄存器
 } PrivateTimer;

-typedef struct {
-    UINT32 low;         /* Global Timer Counter Registers, low bits */
+typedef struct {//全局计数器
+    UINT32 low;         /* Global Timer Counter Registers, low bits */ //需用64位来表示,所以需要高低位
    UINT32 high;        /* Global Timer Counter Registers, high bits */
-    UINT32 control;     /* Global Timer Control Register */
+    UINT32 control;     /* Global Timer Control Register */	
    UINT32 intStatus;   /* Global Timer Interrupt Status Register */
    UINT32 compareLow;  /* Comparator Value Registers, low bits */
    UINT32 compareHigh; /* Comparator Value Registers, high bits */

--- a/platform/hw/hisoc/timer/timer.c
+++ b/platform/hw/hisoc/timer/timer.c
--- a/zzz/git/push.sh
+++ b/zzz/git/push.sh
 git add -A
-git commit -m  '内核哪种任务的优先级是最高的 ?.
+git commit -m  '初始化硬时钟.
    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