📄 os_cpu_c.c
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/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
*
*
* (c) Copyright 1992-2007, Micrium, Weston, FL
* All Rights Reserved
*
* Generic ARM Port
*
* File : OS_CPU_C.C
* Version : V1.82
* By : Jean J. Labrosse
* Jean-Denis Hatier
*
* For : ARM7 or ARM9
* Mode : ARM or Thumb
* Toolchain : RealView Development Suite
* RealView Microcontroller Development Kit (MDK)
* ARM Developer Suite (ADS)
* Keil uVision
*********************************************************************************************************
*/
#define OS_CPU_GLOBALS
#include <ucos_ii.h>
/*$PAGE*/
/*
*********************************************************************************************************
* 本地常量
*********************************************************************************************************
*/
#define ARM_MODE_ARM 0x00000000 //CPSR位被设置为ARM模式
#define ARM_MODE_THUMB 0x00000020 //CPSR位被设置为THUMB模式
#define ARM_SVC_MODE_THUMB (0x00000013L + ARM_MODE_THUMB) //CPSR位被设置为SVC模式+THUMB模式
#define ARM_SVC_MODE_ARM (0x00000013L + ARM_MODE_ARM) //CPSR位被设置为SVC模式+ARM模式
#define OS_NTASKS_FP (OS_MAX_TASKS + OS_N_SYS_TASKS - 1) //有能力处理浮点的任务数
#define OS_FP_STORAGE_SIZE 128L //浮点数存储空间大小
/*
*********************************************************************************************************
* 本地变量
*********************************************************************************************************
*/
#if OS_TMR_EN > 0 //判断是否使能时间管理
static INT16U OSTmrCtr; //定义时间计数器
#endif
#if OS_CPU_FPU_EN > 0 //判断是否使能浮点运算单元(本实例中未使用)
static OS_MEM *OSFPPartPtr;//指向保存浮点运算寄存器存储空间的指针
static INT32U OSFPPart[OS_NTASKS_FP][OS_FP_STORAGE_SIZE / sizeof(INT32U)];
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZE FP SUPPORT
*
* 功能描述: 这个函数用来初始化用来保存浮点运算寄存器的那些存储空间
在上下文切换的过程中，这个函数必须在OSInit()被调用后调用
为了能编译浮点运算模块必须将 OS_CPU_FPU_EN定义为大于0
*
*入口参数: 无
*
*返回参数: 无
*
注意事项: 1)用到浮点运算功能的任务必须用OSTaskCreateExt()创建。
* 2)对于ARM的浮点协处理器要求用128 bytes来保存浮点协处理器的上下文切换。
* 3)如果你需要从OSStatTaskHook()内部完成浮点运算任务，你必须建立这个statistics任务的时候
改变OSTaskCreatExt()的属性选项。这只需要OS_TaskStat()用OSTaskCreateExt()建立。
*********************************************************************************************************
*/
#if OS_CPU_FPU_EN > 0
void OS_CPU_FP_Init (void)
{
INT8U err;
#if OS_TASK_STAT_EN && OS_TASK_CREATE_EXT_EN
OS_TCB *ptcb;
void *pblk;
#endif
OSFPPartPtr = OSMemCreate(&OSFPPart[0][0], OS_NTASKS_FP, OS_FP_STORAGE_SIZE, &err);
#if OS_TASK_STAT_EN && OS_TASK_CREATE_EXT_EN /* CHANGE 'OPTIONS' for OS_TaskStat() */
ptcb = OSTCBPrioTbl[OS_TASK_STAT_PRIO];
ptcb->OSTCBOpt |= OS_TASK_OPT_SAVE_FP; /* Allow floating-point support for Statistic task */
pblk = OSMemGet(OSFPPartPtr, &err); /* Get storage for VFP registers */
if (pblk != (void *)0) { /* Did we get a memory block? */
ptcb->OSTCBExtPtr = pblk; /* Yes, Link to task's TCB */
OS_CPU_FP_Save(pblk); /* Save the VFP registers in block */
}
#endif
}
#endif
/*
*********************************************************************************************************
* OS INITIALIZATION HOOK
* (BEGINNING)
*
* Description: This function is called by OSInit() at the beginning of OSInit().
*
* Arguments : none
*
* Note(s) : 1) Interrupts should be disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void OSInitHookBegin (void)
{
#if OS_TMR_EN > 0
OSTmrCtr = 0;
#endif
}
#endif
/*
*********************************************************************************************************
* OS INITIALIZATION HOOK
* (END)
*
* Description: This function is called by OSInit() at the end of OSInit().
*
* Arguments : none
*
* Note(s) : 1) Interrupts should be disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void OSInitHookEnd (void)
{
#if OS_CPU_INT_DIS_MEAS_EN > 0
OS_CPU_IntDisMeasInit();
#endif
#if OS_CPU_FPU_EN > 0
OS_CPU_FP_Init(); /* Initialize support for VFP register save / restore */
#endif
}
#endif
/*
*********************************************************************************************************
* TASK CREATION HOOK
*
* Description: This function is called when a task is created.
*
* Arguments : ptcb is a pointer to the task control block of the task being created.
*
* Note(s) : 1) Interrupts are disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void OSTaskCreateHook (OS_TCB *ptcb)
{
#if OS_CPU_FPU_EN > 0
INT8U err;
void *pblk;
#endif
#if OS_CPU_FPU_EN > 0
if (ptcb->OSTCBOpt & OS_TASK_OPT_SAVE_FP) { /* See if task needs FP support */
pblk = OSMemGet(OSFPPartPtr, &err); /* Yes, Get storage for VFP registers */
if (pblk != (void *)0) { /* Did we get a memory block? */
ptcb->OSTCBExtPtr = pblk; /* Yes, Link to task's TCB */
OS_CPU_FP_Save(pblk); /* Save the VFP registers in block */
}
}
#endif
#if OS_APP_HOOKS_EN > 0
App_TaskCreateHook(ptcb);
#else
(void)ptcb; /* Prevent compiler warning */
#endif
}
#endif
/*
*********************************************************************************************************
* TASK DELETION HOOK
*
* Description: This function is called when a task is deleted.
*
* Arguments : ptcb is a pointer to the task control block of the task being deleted.
*
* Note(s) : 1) Interrupts are disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void OSTaskDelHook (OS_TCB *ptcb)
{
#if OS_CPU_FPU_EN > 0
if (ptcb->OSTCBOpt & OS_TASK_OPT_SAVE_FP) { /* See if task had FP support */
if (ptcb->OSTCBExtPtr != (void *)0) { /* Yes, OSTCBExtPtr must not be NULL */
OSMemPut(OSFPPartPtr, ptcb->OSTCBExtPtr); /* Return memory block to free pool */
}
}
#endif
#if OS_APP_HOOKS_EN > 0
App_TaskDelHook(ptcb);
#else
(void)ptcb; /* Prevent compiler warning */
#endif
}
#endif
/*
*********************************************************************************************************
* IDLE TASK HOOK
*
* Description: This function is called by the idle task. This hook has been added to allow you to do
* such things as STOP the CPU to conserve power.
*
* Arguments : none
*
* Note(s) : 1) Interrupts are enabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION >= 251
void OSTaskIdleHook (void)
{
#if OS_CPU_ARM_DCC_EN > 0
OSDCC_Handler();
#endif
#if OS_APP_HOOKS_EN > 0
App_TaskIdleHook();
#endif
}
#endif
/*
*********************************************************************************************************
* STATISTIC TASK HOOK
*
* Description: This function is called every second by uC/OS-II's statistics task. This allows your
* application to add functionality to the statistics task.
*
* Arguments : none
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void OSTaskStatHook (void)
{
#if OS_APP_HOOKS_EN > 0
App_TaskStatHook();
#endif
}
#endif
/*
*********************************************************************************************************
* INITIALIZE A TASK'S STACK
*
* Description: This function is called by either OSTaskCreate() or OSTaskCreateExt() to initialize the
* stack frame of the task being created. This function is highly processor specific.
*
* Arguments : task is a pointer to the task code
*
* p_arg is a pointer to a user supplied data area that will be passed to the task
* when the task first executes.
*
* ptos is a pointer to the top of stack. It is assumed that 'ptos' points to
* a 'free' entry on the task stack. If OS_STK_GROWTH is set to 1 then
* 'ptos' will contain the HIGHEST valid address of the stack. Similarly, if
* OS_STK_GROWTH is set to 0, the 'ptos' will contains the LOWEST valid address
* of the stack.
*
* opt specifies options that can be used to alter the behavior of OSTaskStkInit().
* (see uCOS_II.H for OS_TASK_OPT_xxx).
*
* Returns : Always returns the location of the new top-of-stack' once the processor registers have
* been placed on the stack in the proper order.
*
* Note(s) : 1) Interrupts are enabled when your task starts executing.
* 2) All tasks run in SVC mode.
*********************************************************************************************************
*/
OS_STK *OSTaskStkInit (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT16U opt)
{
OS_STK *stk;
INT32U task_addr;
opt = opt; /* 'opt' is not used, prevent warning */
stk = ptos; /* Load stack pointer */
task_addr = (INT32U)task & ~1; /* Mask off lower bit in case task is thumb mode */
*(stk) = (INT32U)task_addr; /* Entry Point */
*(--stk) = (INT32U)0x14141414L; /* R14 (LR) */
*(--stk) = (INT32U)0x12121212L; /* R12 */
*(--stk) = (INT32U)0x11111111L; /* R11 */
*(--stk) = (INT32U)0x10101010L; /* R10 */
*(--stk) = (INT32U)0x09090909L; /* R9 */
*(--stk) = (INT32U)0x08080808L; /* R8 */
*(--stk) = (INT32U)0x07070707L; /* R7 */
*(--stk) = (INT32U)0x06060606L; /* R6 */
*(--stk) = (INT32U)0x05050505L; /* R5 */
*(--stk) = (INT32U)0x04040404L; /* R4 */
*(--stk) = (INT32U)0x03030303L; /* R3 */
*(--stk) = (INT32U)0x02020202L; /* R2 */
*(--stk) = (INT32U)0x01010101L; /* R1 */
*(--stk) = (INT32U)p_arg; /* R0 : argument */
if ((INT32U)task & 0x01) { /* See if task runs in Thumb or ARM mode */
*(--stk) = (INT32U)ARM_SVC_MODE_THUMB; /* CPSR (Enable both IRQ and FIQ interrupts, THUMB-mode) */
} else {
*(--stk) = (INT32U)ARM_SVC_MODE_ARM; /* CPSR (Enable both IRQ and FIQ interrupts, ARM-mode) */
}
return (stk);
}
/*
*********************************************************************************************************
* TASK SWITCH HOOK
*
* Description: This function is called when a task switch is performed. This allows you to perform other
* operations during a context switch.
*
* Arguments : none
*
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