?? os_core.c
字號:
/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* CORE FUNCTIONS
*
* (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
* All Rights Reserved
*
* File : OS_CORE.C
* By : Jean J. Labrosse
*********************************************************************************************************
*/
#ifndef OS_MASTER_FILE//防止一些文件加入到includes.h當中
#define OS_GLOBALS
#include "includes.h"
#endif
/*
*********************************************************************************************************
* MAPPING TABLE TO MAP BIT POSITION TO BIT MASK
*
* Note: Index into table is desired bit position, 0..7
* Indexed value corresponds to bit mask
*********************************************************************************************************
*/
/*
*********************************************************************************************************
映射位位置映射到位掩碼的映射表
備注：表的索引是想得到的位的位置（0到7）
索引得到的值是位的掩碼
*********************************************************************************************************
*/
INT8U const OSMapTbl[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
/*
*********************************************************************************************************
* PRIORITY RESOLUTION TABLE
*
* Note: Index into table is bit pattern to resolve highest priority
* Indexed value corresponds to highest priority bit position (i.e. 0..7)
*********************************************************************************************************
*/
/*
**********************************************************************************************
優先級分辨表
備注：索引表是最高優先級的位模式
索引值對應于最高優先級的位位置（0到7）
***********************************************************************************************
*/
INT8U const OSUnMapTbl[] = {
0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x00 to 0x0F */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x10 to 0x1F */
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x20 to 0x2F */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x30 to 0x3F */
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x40 to 0x4F */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x50 to 0x5F */
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x60 to 0x6F */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x70 to 0x7F */
7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x80 to 0x8F */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x90 to 0x9F */
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0xA0 to 0xAF */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0xB0 to 0xBF */
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0xC0 to 0xCF */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0xD0 to 0xDF */
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0xE0 to 0xEF */
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 /* 0xF0 to 0xFF */
};//256個東東，干嘛呢？
/*
*********************************************************************************************************
* FUNCTION PROTOTYPES
*********************************************************************************************************
*/
//以下為初始化函數
static void OS_InitEventList(void);//初始化事件控制塊的空表
static void OS_InitMisc(void);//初始化其它約定的值
static void OS_InitRdyList(void);//初始化就緒列表
static void OS_InitTaskIdle(void);//建立空閑任務
static void OS_InitTaskStat(void);//建立一個統計任務
static void OS_InitTCBList(void);//初始化任務控制塊的空閑表
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
*
* Description: This function is used to initialize the internals of uC/OS-II and MUST be called prior to
* creating any uC/OS-II object and, prior to calling OSStart().
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
/*
*********************************************************************************************************
初始化
功能：要先在調用 OSStart()后，再初始化uxosII內核，要先建立ucos任何一個任務
*********************************************************************************************************
*/
void OSInit (void)
{
#if OS_VERSION >= 204
OSInitHookBegin(); /* Call port specific initialization code */
//調用特定通信口初始化代碼
#endif
OS_InitMisc(); /* Initialize miscellaneous variables */
//初始化多種變量
OS_InitRdyList(); /* Initialize the Ready List */
//初始化就緒鏈表
OS_InitTCBList(); /* Initialize the free list of OS_TCBs */
//初始化TCB空閑鏈表
OS_InitEventList(); /* Initialize the free list of OS_EVENTs */
//初始化事件空閑鏈表
#if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
OS_FlagInit(); /* Initialize the event flag structures */
//初始化事件標志結構
#endif
#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)
OS_MemInit(); /* Initialize the memory manager */
//初始化存在管理
#endif
#if (OS_Q_EN > 0) && (OS_MAX_QS > 0)
OS_QInit(); /* Initialize the message queue structures */
//初始化消息隊列結構
#endif
OS_InitTaskIdle(); /* Create the Idle Task */
//建立空閑任務
#if OS_TASK_STAT_EN > 0
OS_InitTaskStat(); /* Create the Statistic Task */
//建立統計任務
#endif
#if OS_VERSION >= 204
OSInitHookEnd(); /* Call port specific init. code */
//調用專用通信口初始化代碼
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* ENTER ISR
*
* Description: This function is used to notify uC/OS-II that you are about to service an interrupt
* service routine (ISR). This allows uC/OS-II to keep track of interrupt nesting and thus
* only perform rescheduling at the last nested ISR.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) This function should be called ith interrupts already disabled
* 2) Your ISR can directly increment OSIntNesting without calling this function because
* OSIntNesting has been declared 'global'.
* 3) You MUST still call OSIntExit() even though you increment OSIntNesting directly.
* 4) You MUST invoke OSIntEnter() and OSIntExit() in pair. In other words, for every call
* to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
* end of the ISR.
* 5) You are allowed to nest interrupts up to 255 levels deep.
* 6) I removed the OS_ENTER_CRITICAL() and OS_EXIT_CRITICAL() around the increment because
* OSIntEnter() is always called with interrupts disabled.
進入中斷服務程序
描述：通知ucosII將進入中斷服務程序，它允許ucos跟蹤中斷嵌套，所以只有
//在最后一層中斷嵌套才重新安排。
參數：無
返回：無
注意：1、只有在關中斷的時候才調用
2、因為中斷嵌套定義為全局變量，所以在沒有調用此函數的時候
也可以增加中斷嵌套數
3、即使你增加了中斷嵌套數，你也要調用OSIntExit()
4、你必須成對調用OSIntEnter() and OSIntExit()，即：每次在ISR開始時調用OSIntEnter()
你將在ISR結束時調用OSIntExit()
5、你可以嵌套255層深
6、因為每次調用時中斷是關的，所以我去掉了OS_ENTER_CRITICAL() and OS_EXIT_CRITICAL()
*********************************************************************************************************
*/
void OSIntEnter (void)
{
if (OSRunning == TRUE) {
if (OSIntNesting < 255) {
OSIntNesting++; /* Increment ISR nesting level */
}//增加中斷嵌套數
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* EXIT ISR
*
* Description: This function is used to notify uC/OS-II that you have completed serviving an ISR. When
* the last nested ISR has completed, uC/OS-II will call the scheduler to determine whether
* a new, high-priority task, is ready to run.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) You MUST invoke OSIntEnter() and OSIntExit() in pair. In other words, for every call
* to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
* end of the ISR.
* 2) Rescheduling is prevented when the scheduler is locked (see OS_SchedLock())
退出中斷
描述：通知ucos你已經完成中斷服務程序，當最后一層嵌套完成后，ucos將
重新調度看是否一個新的，高優先級任務將就緒。
參數：無
返回：無
備注：1、你必須成對調用OSIntEnter() and OSIntExit()，即：每次在ISR開始時調用OSIntEnter()
你將在ISR結束時調用OSIntExit()
2、當調度上鎖的話，重新調度是不允許的。見OS_SchedLock()(就在下面)
*********************************************************************************************************
*/
void OSIntExit (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
if (OSRunning == TRUE) {//如果正在運行
OS_ENTER_CRITICAL();
if (OSIntNesting > 0) { /* Prevent OSIntNesting from wrapping */
//防止減到比0還小
OSIntNesting--;
}
if ((OSIntNesting == 0) && (OSLockNesting == 0)) { /* Reschedule only if all ISRs complete ... */
OSIntExitY = OSUnMapTbl[OSRdyGrp]; /* ... and not locked. */
OSPrioHighRdy = (INT8U)((OSIntExitY << 3) + OSUnMapTbl[OSRdyTbl[OSIntExitY]]);
//看到幾遍了，就是不會算啊！哪交要算算
//終于明白了！！！！！！！！！！！！！！
if (OSPrioHighRdy != OSPrioCur) { /* No Ctx Sw if current task is highest rdy */
OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];
//如果當前任務不是最高優先級，將最高優先級放入最高優先級標志中。
OSCtxSwCtr++; /* Keep track of the number of ctx switches */
//跟蹤任務轉換次數
OSIntCtxSw(); /* Perform interrupt level ctx switch */
//執行中斷水平任務切換？？？
}
}
OS_EXIT_CRITICAL();
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* PREVENT SCHEDULING
*
* Description: This function is used to prevent rescheduling to take place. This allows your application
* to prevent context switches until you are ready to permit context switching.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) You MUST invoke OSSchedLock() and OSSchedUnlock() in pair. In other words, for every
* call to OSSchedLock() you MUST have a call to OSSchedUnlock().
調度上鎖函數
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