shell 物理内存，虚拟内存，VDSO，文件操作 部分注释说明

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项目给鸿蒙内核源码逐行加上中文注解,详细阐述框架和代码细节, 精读 HarmonyOS 内核源码, 将迅速拔高对计算机整体理解,从此高屋建瓴看问题.

compat/posix/src/socket.c

@@ -37,14 +37,14 @@
 #include <lwip/sockets.h>
 
 #if !LWIP_COMPAT_SOCKETS
-
+//	详见： ..\vendor_hisi_hi3861_hi3861\hi3861\third_party\lwip_sack\include\lwip\sockets.h
 #define CHECK_NULL_PTR(ptr) do { if (ptr == NULL) { set_errno(EFAULT); return -1; } } while (0)
-
+//接受连接 
 int accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 {
     return lwip_accept(s, addr, addrlen);
 }
-
+//socket与IP地址绑定。
 int bind(int s, const struct sockaddr *name, socklen_t namelen)
 {
     CHECK_NULL_PTR(name);
@@ -54,41 +54,41 @@ int bind(int s, const struct sockaddr *name, socklen_t namelen)
     }
     return lwip_bind(s, name, namelen);
 }
-
+//关闭连接
 int shutdown(int s, int how)
 {
     return lwip_shutdown(s, how);
 }
-
+//获取对端地址
 int getpeername(int s, struct sockaddr *name, socklen_t *namelen)
 {
     CHECK_NULL_PTR(name);
     CHECK_NULL_PTR(namelen);
     return lwip_getpeername(s, name, namelen);
 }
-
+//获取本地地址
 int getsockname(int s, struct sockaddr *name, socklen_t *namelen)
 {
     CHECK_NULL_PTR(name);
     CHECK_NULL_PTR(namelen);
     return lwip_getsockname(s, name, namelen);
 }
-
+//获取socket属性信息
 int getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
 {
     return lwip_getsockopt(s, level, optname, optval, optlen);
 }
-
+//配置socket属性
 int setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
 {
     return lwip_setsockopt(s, level, optname, optval, optlen);
 }
-
+//关闭socket
 int closesocket(int s)
 {
     return lwip_close(s);
 }
-
+//	连接到指定的目的IP
 int connect(int s, const struct sockaddr *name, socklen_t namelen)
 {
     CHECK_NULL_PTR(name);
@@ -98,25 +98,25 @@ int connect(int s, const struct sockaddr *name, socklen_t namelen)
     }
     return lwip_connect(s, name, namelen);
 }
-
+//监听本socket的请求
 int listen(int s, int backlog)
 {
     return lwip_listen(s, backlog);
 }
-
+//接收socket上收到的数据
 ssize_t recv(int s, void *mem, size_t len, int flags)
 {
     CHECK_NULL_PTR(mem);
     return lwip_recv(s, mem, len, flags);
 }
-
+//接收socket上收到的数据，可同时获得数据来源IP地址
 ssize_t recvfrom(int s, void *mem, size_t len, int flags,
                  struct sockaddr *from, socklen_t *fromlen)
 {
     CHECK_NULL_PTR(mem);
     return lwip_recvfrom(s, mem, len, flags, from, fromlen);
 }
-
+//接收socket上收到的数据，可使用更丰富的参数
 ssize_t recvmsg(int s, struct msghdr *message, int flags)
 {
     CHECK_NULL_PTR(message);
@@ -125,18 +125,18 @@ ssize_t recvmsg(int s, struct msghdr *message, int flags)
     }
     return lwip_recvmsg(s, message, flags);
 }
-
+//通过socket发送数据
 ssize_t send(int s, const void *dataptr, size_t size, int flags)
 {
     CHECK_NULL_PTR(dataptr);
     return  lwip_send(s, dataptr, size, flags);
 }
-
+//	通过socket发送数据，可使用更丰富的参数
 ssize_t sendmsg(int s, const struct msghdr *message, int flags)
 {
     return lwip_sendmsg(s, message, flags);
 }
-
+//通过socket发送数据，可指定发送的目的IP地址
 ssize_t sendto(int s, const void *dataptr, size_t size, int flags,
                const struct sockaddr *to, socklen_t tolen)
 {
@@ -147,17 +147,17 @@ ssize_t sendto(int s, const void *dataptr, size_t size, int flags,
     }
     return lwip_sendto(s, dataptr, size, flags, to, tolen);
 }
-
+//	创建socket
 int socket(int domain, int type, int protocol)
 {
     return lwip_socket(domain, type, protocol);
 }
-
+//网络地址格式转换：将二进制格式IP地址转换为字符串格式。
 const char *inet_ntop(int af, const void *src, char *dst, socklen_t size)
 {
     return lwip_inet_ntop(af, src, dst, size);
 }
-
+//	网络地址格式转换：将字符串格式IP地址转换为二进制格式。
 int inet_pton(int af, const char *src, void *dst)
 {
     return lwip_inet_pton(af, src, dst);

fs/vfs/operation/fs_init.c

@@ -37,7 +37,8 @@
 #include "sys/statfs.h"
 #include "linux/spinlock.h"
 #include "disk_pri.h"
-
+//VFS是Virtual File System（虚拟文件系统）的缩写，它不是一个实际的文件系统，而是一个异构文件系统之上的软件粘合层
+//虚拟文件系统初始化
 void los_vfs_init(void)
 {
     int err;

kernel/common/los_config.c

@@ -329,8 +329,8 @@ LITE_OS_SEC_TEXT_INIT INT32 OsMain(VOID)
     }
 #endif
 
-#ifdef LOSCFG_KERNEL_PIPE
-    OsDriverPipeInit();
+#ifdef LOSCFG_KERNEL_PIPE	//打开管道宏
+    OsDriverPipeInit();//管道init
 #endif
 
     ret = OsSystemInit();//系统初始化
@@ -338,8 +338,8 @@ LITE_OS_SEC_TEXT_INIT INT32 OsMain(VOID)
         return ret;
     }
 
-#if LOSCFG_DRIVERS_HIEVENT
-    OsDriverHiEventInit();
+#if LOSCFG_DRIVERS_HIEVENT //打开HIEVENT宏
+    OsDriverHiEventInit();//HiEvent 初始化
 #endif
 
 #if (LOSCFG_KERNEL_TRACE == YES)
@@ -380,22 +380,22 @@ LITE_OS_SEC_TEXT_INIT INT32 OsMain(VOID)
 
     return LOS_OK;
 }
-
+//创建系统初始化任务
 STATIC UINT32 OsSystemInitTaskCreate(VOID)
 {
     UINT32 taskID;
     TSK_INIT_PARAM_S sysTask;
 
     (VOID)memset_s(&sysTask, sizeof(TSK_INIT_PARAM_S), 0, sizeof(TSK_INIT_PARAM_S));
-    sysTask.pfnTaskEntry = (TSK_ENTRY_FUNC)SystemInit;
+    sysTask.pfnTaskEntry = (TSK_ENTRY_FUNC)SystemInit;//外部函数，
     sysTask.uwStackSize = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
     sysTask.pcName = "SystemInit";
-    sysTask.usTaskPrio = LOSCFG_BASE_CORE_TSK_DEFAULT_PRIO;
-    sysTask.uwResved = LOS_TASK_STATUS_DETACHED;
+    sysTask.usTaskPrio = LOSCFG_BASE_CORE_TSK_DEFAULT_PRIO;// 10 
+    sysTask.uwResved = LOS_TASK_STATUS_DETACHED;//任务分离模式
 #if (LOSCFG_KERNEL_SMP == YES)
     sysTask.usCpuAffiMask = CPUID_TO_AFFI_MASK(ArchCurrCpuid());
 #endif
-    return LOS_TaskCreate(&taskID, &sysTask);
+    return LOS_TaskCreate(&taskID, &sysTask);//创建任务
 }
 
 #ifdef LOSCFG_MEM_RECORDINFO
@@ -418,17 +418,17 @@ UINT32 OsSystemInit(VOID)
 {
     UINT32 ret;
 #ifdef LOSCFG_FS_VFS
-    los_vfs_init();
+    los_vfs_init(); //虚拟文件初始化
 #endif
 #ifdef LOSCFG_COMPAT_LINUXKPI
     g_pstSystemWq = create_workqueue("system_wq");
 #endif
-    ret = OsSystemInitTaskCreate();
+    ret = OsSystemInitTaskCreate();//创建 "SystemInit" 任务
     if (ret != LOS_OK) {
         return ret;
     }
 #ifdef LOSCFG_MEM_RECORDINFO
-    ret = OsMemShowTaskCreate();
+    ret = OsMemShowTaskCreate();//创建 "memshow_task"任务，用于显示虚拟内存使用
     if (ret != LOS_OK) {
         PRINTK("create memshow_Task error %u\n", ret);
         return ret;

kernel/extended/trace/los_trace.c

@@ -50,7 +50,7 @@ STATIC SPIN_LOCK_S g_traceCpuSpin[LOSCFG_KERNEL_CORE_NUM];
 #define TRACE_CPU_LOCK(state, cpuID)       LOS_SpinLockSave(&g_traceCpuSpin[(cpuID)], &(state))
 #define TRACE_CPU_UNLOCK(state, cpuID)     LOS_SpinUnlockRestore(&g_traceCpuSpin[(cpuID)], (state))
 
-STATIC TraceBuffer g_traceBuf[LOSCFG_KERNEL_CORE_NUM];
+STATIC TraceBuffer g_traceBuf[LOSCFG_KERNEL_CORE_NUM];//每个CPU core都有traceBuf
 STATIC TraceHook *g_traceInfo[LOS_TRACE_TYPE_NUM];
 STATIC UINT16 g_frameSize[LOS_TRACE_TYPE_NUM];
 

kernel/include/los_trace.h

@@ -121,40 +121,40 @@ typedef UINT16 (*WriteHook)(UINT8 *inBuf, UINT32 newID, UINT32 oldID);
  * Stands for the trace type can be registered.
  */
 typedef enum {
-    LOS_TRACE_SWITCH    = 0,                /**< trace for task switch, 0 is reserved for taskswitch */
-    LOS_TRACE_INTERRUPT = 1,                /**< trace for Interrrupt, 1 is reserved for interrupt */
+    LOS_TRACE_SWITCH    = 0,                /**< trace for task switch, 0 is reserved for taskswitch */ //任务切换的跟踪，0是为taskswitch保留的
+    LOS_TRACE_INTERRUPT = 1,                /**< trace for Interrrupt, 1 is reserved for interrupt */	//中断，1表示为中断保留
     LOS_TRACE_TYPE_NUM  = 5,                /**< num for the register type, user can use 2~ LOS_TRACE_TYPE_NUM-1 */
 } TraceType;
 
 /**
  * @ingroup los_trace
- * struct to store the trace infomation
+ * struct to store the trace infomation	//结构来存储跟踪信息
  */
 typedef struct {
-    UINTPTR tracePos;                       /**< Data buffer current index position */
-    UINTPTR traceWrapPos;                   /**< Data buffer last loop end position */
-    UINT8   dataBuf[LOS_TRACE_BUFFER_SIZE]; /**< Data buffer */
+    UINTPTR tracePos;                       /**< Data buffer current index position */	//数据缓冲区当前索引位置
+    UINTPTR traceWrapPos;                   /**< Data buffer last loop end position */	//数据缓冲区最后一个循环结束位置
+    UINT8   dataBuf[LOS_TRACE_BUFFER_SIZE]; /**< Data buffer */		//数据缓存区
 } TraceBuffer;
 
 /**
  * @ingroup los_trace
- * struct to store the task switch infomation
+ * struct to store the task switch infomation	//结构来存储任务切换的信息
  */
 typedef struct {
-    UINT32  srcTaskId;                      /**< source taskid */
-    UINT32  destTaskId;                     /**< destination taskid */
-    UINT64  currentTick;                    /**< Time at which the task switch happens */
+    UINT32  srcTaskId;                      /**< source taskid */	//源任务ID
+    UINT32  destTaskId;                     /**< destination taskid */	//目标任务ID
+    UINT64  currentTick;                    /**< Time at which the task switch happens */	//任务上下文切换时发生的时间
 } TaskTraceFrame;
 
 /**
  * @ingroup los_trace
- * struct to store the interrupt infomation
+ * struct to store the interrupt infomation	//结构来存储中断信息
  */
 typedef struct {
-    UINT32  irqDirection;                   /**< IRQ_DIRECT_IN  stands for entering the irq handler */
-                                            /**< IRQ_DIRECT_OUT stands for leaving the previous irq handler */
-    UINT32  irqNum;                         /**< IRQ number which trigger the interrupt */
-    UINT64  currentTick;                    /**< Time at which the the trace is called */
+    UINT32  irqDirection;                   /**< IRQ_DIRECT_IN  stands for entering the irq handler */	//IRQ_DIRECT_IN代表进入IRQ处理程序
+                                            /**< IRQ_DIRECT_OUT stands for leaving the previous irq handler *///IRQ_DIRECT_OUT代表离开IRQ之前的处理程序
+    UINT32  irqNum;                         /**< IRQ number which trigger the interrupt */	//触发中断的IRQ号
+    UINT64  currentTick;                    /**< Time at which the the trace is called */ //trace被调用的时间
 } IntTraceFrame;
 
 /**

net/lwip-2.1/enhancement/src/api_shell.c

@@ -1338,7 +1338,21 @@ LWIP_STATIC void lwip_arp_usage(const char *cmd)
          "\n%s [-i IF] -d IPADDR\n",
            cmd, cmd, cmd);
 }
-
+/****************************************************************
+命令功能
+在以太网中，主机之间的通信是直接使用MAC地址（非IP地址）来通信的，所以，对于使用IP通信的协议，
+必须能够将IP地址转换成MAC地址，才能在局域网（以太网）内通信。解决这个问题的方法就是主机存储
+一张IP和MAC地址对应的表，即ARP缓存，主机要往一个局域网内的目的IP地址发送IP包时，就可以从ARP
+缓存表中查询到目的MAC地址。ARP缓存是由TCP/IP协议栈维护的，用户可通过ARP命令查看和修改ARP表。
+命令格式
+arp
+arp [-i IF] -s IPADDR HWADDR
+arp [-i IF] -d IPADDR
+使用指南
+arp命令用来查询和修改TCP/IP协议栈的ARP缓存表，增加非同一子网内的IP地址的ARP表项是没有意义的，协议栈会返回失败。
+命令需要启动TCP/IP协议栈后才能使用。
+shell arp 打印整个 ARP 缓存表
+****************************************************************/
 u32_t lwip_arp(int argc, const char **argv)
 {
     int i;
@@ -1364,7 +1378,7 @@ u32_t lwip_arp(int argc, const char **argv)
 
     i = 0;
     while (argc > 0) {
-        if (strcmp("-i", argv[i]) == 0 && (argc > 1)) {
+        if (strcmp("-i", argv[i]) == 0 && (argc > 1)) {//指定的网络接口（可选参数）
             /* get the network interface's name */
             interface_len = strlen(argv[i + 1]);
             if (interface_len < IFNAMSIZ) {
@@ -1383,7 +1397,8 @@ u32_t lwip_arp(int argc, const char **argv)
             }
             i += 2;
             argc -= 2;
-        } else if (strcmp("-d", argv[i]) == 0 && (argc > 1)) {
+        } else if (strcmp("-d", argv[i]) == 0 && (argc > 1)) {//删除一条ARP表项。
+			
             /* arp delete */
             arp_cmd.option = ARP_OPTION_DEL;
             arp_cmd.ipaddr = inet_addr(argv[i + 1]);
@@ -1395,7 +1410,7 @@ u32_t lwip_arp(int argc, const char **argv)
 
             i += 2;
             argc -= 2;
-        } else if (strcmp("-s", argv[i]) == 0 && (argc > 2)) {
+        } else if (strcmp("-s", argv[i]) == 0 && (argc > 2)) {//增加一条ARP表项，后面的参数是局域网中另一台主机的IP地址及其对应的MAC地址。
             /* arp add */
             char *digit = NULL;
             u32_t macaddrlen = strlen(argv[i + 2]) + 1;