📄 os_core.c
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/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* CORE FUNCTIONS
*
* (c) Copyright 1992-2008, Micrium, Weston, FL
* All Rights Reserved
*
* File : OS_CORE.C
* By : Jean J. Labrosse
* Version : V2.87
*
* LICENSING TERMS:
* ---------------
* uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research.
* If you plan on using uC/OS-II in a commercial product you need to contact Micri祄 to properly license
* its use in your product. We provide ALL the source code for your convenience and to help you experience
* uC/OS-II. The fact that the source is provided does NOT mean that you can use it without paying a
* licensing fee.
*********************************************************************************************************
*/
#ifndef OS_MASTER_FILE
#define OS_GLOBALS
#include "includes.h"
#endif
extern void OSIntCtxSw(void);
extern void OSStartHighRdy(void);
/*
*********************************************************************************************************
* 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)
*********************************************************************************************************
*/
INT8U const OSUnMapTbl[256] = {
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 */
};
/*$PAGE*/
/*
*********************************************************************************************************
* FUNCTION PROTOTYPES
*********************************************************************************************************
*/
static void OS_InitEventList(void);
static void OS_InitMisc(void);
static void OS_InitRdyList(void);
static void OS_InitTaskIdle(void);
#if OS_TASK_STAT_EN > 0
static void OS_InitTaskStat(void);
#endif
static void OS_InitTCBList(void);
static void OS_SchedNew(void);
/*$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
*********************************************************************************************************
*/
void OSInit (void)
{
OSInitHookBegin(); /* Call port specific initialization code */
OS_InitMisc(); /* Initialize miscellaneous variables */
OS_InitRdyList(); /* Initialize the Ready List */
OS_InitTCBList(); /* Initialize the free list of OS_TCBs */
OS_InitEventList(); /* Initialize the free list of OS_EVENTs */
#if (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
OS_FlagInit(); /* Initialize the event flag structures */
#endif
#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)
OS_MemInit(); /* Initialize the memory manager */
#endif
#if (OS_Q_EN > 0) && (OS_MAX_QS > 0)
OS_QInit(); /* Initialize the message queue structures */
#endif
OS_InitTaskIdle(); /* Create the Idle Task */
#if OS_TASK_STAT_EN > 0
OS_InitTaskStat(); /* Create the Statistic Task */
#endif
#if OS_TMR_EN > 0
OSTmr_Init(); /* Initialize the Timer Manager */
#endif
OSInitHookEnd(); /* Call port specific init. code */
#if OS_DEBUG_EN > 0
OSDebugInit();
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* ENTER ISR
*
* Description: This function is used to notify uC/OS-II that you are about to service an interrupt
* service routine (ISR). This allows uC/OS-II to keep track of interrupt nesting and thus
* only perform rescheduling at the last nested ISR.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) This function should be called ith interrupts already disabled
* 2) Your ISR can directly increment OSIntNesting without calling this function because
* OSIntNesting has been declared 'global'.
* 3) You MUST still call OSIntExit() even though you increment OSIntNesting directly.
* 4) You MUST invoke OSIntEnter() and OSIntExit() in pair. In other words, for every call
* to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
* end of the ISR.
* 5) You are allowed to nest interrupts up to 255 levels deep.
* 6) I removed the OS_ENTER_CRITICAL() and OS_EXIT_CRITICAL() around the increment because
* OSIntEnter() is always called with interrupts disabled.
*********************************************************************************************************
*/
void OSIntEnter (void)
{
if (OSRunning == OS_TRUE) {
if (OSIntNesting < 255u) {
OSIntNesting++; /* Increment ISR nesting level */
}
}
}
/*$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())
*********************************************************************************************************
*/
void OSIntExit (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
if (OSRunning == OS_TRUE) {
OS_ENTER_CRITICAL();
if (OSIntNesting > 0) { /* Prevent OSIntNesting from wrapping */
OSIntNesting--;
}
if (OSIntNesting == 0) { /* Reschedule only if all ISRs complete ... */
if (OSLockNesting == 0) { /* ... and not locked. */
OS_SchedNew();
if (OSPrioHighRdy != OSPrioCur) { /* No Ctx Sw if current task is highest rdy */
OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];
#if OS_TASK_PROFILE_EN > 0
OSTCBHighRdy->OSTCBCtxSwCtr++; /* Inc. # of context switches to this task */
#endif
OSCtxSwCtr++; /* Keep track of the number of ctx switches */
OSIntCtxSw(); /* Perform interrupt level ctx switch */
}
}
}
OS_EXIT_CRITICAL();
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* PREVENT SCHEDULING
*
* Description: This function is used to prevent rescheduling to take place. This allows your application
* to prevent context switches until you are ready to permit context switching.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) You MUST invoke OSSchedLock() and OSSchedUnlock() in pair. In other words, for every
* call to OSSchedLock() you MUST have a call to OSSchedUnlock().
*********************************************************************************************************
*/
#if OS_SCHED_LOCK_EN > 0
void OSSchedLock (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
if (OSRunning == OS_TRUE) { /* Make sure multitasking is running */
OS_ENTER_CRITICAL();
if (OSIntNesting == 0) { /* Can't call from an ISR */
if (OSLockNesting < 255u) { /* Prevent OSLockNesting from wrapping back to 0 */
OSLockNesting++; /* Increment lock nesting level */
}
}
OS_EXIT_CRITICAL();
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* ENABLE SCHEDULING
*
* Description: This function is used to re-allow rescheduling.
*
* 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().
*********************************************************************************************************
*/
#if OS_SCHED_LOCK_EN > 0
void OSSchedUnlock (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
if (OSRunning == OS_TRUE) { /* Make sure multitasking is running */
OS_ENTER_CRITICAL();
if (OSLockNesting > 0) { /* Do not decrement if already 0 */
OSLockNesting--; /* Decrement lock nesting level */
if (OSLockNesting == 0) { /* See if scheduler is enabled and ... */
if (OSIntNesting == 0) { /* ... not in an ISR */
OS_EXIT_CRITICAL();
OS_Sched(); /* See if a HPT is ready */
} else {
OS_EXIT_CRITICAL();
}
} else {
OS_EXIT_CRITICAL();
}
} else {
OS_EXIT_CRITICAL();
}
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* START MULTITASKING
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