📄 os_cpu_c.c
字号:
#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 IRQ and FIQ interrupts, THUMB-mode) */
} else {
*(--stk) = (INT32U)ARM_SVC_MODE_ARM; /* CPSR (Enable 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
*
* Note(s) : 1) Interrupts are disabled during this call.
* 2) It is assumed that the global pointer 'OSTCBHighRdy' points to the TCB of the task that
* will be 'switched in' (i.e. the highest priority task) and, 'OSTCBCur' points to the
* task being switched out (i.e. the preempted task).
*********************************************************************************************************
*/
#if (OS_CPU_HOOKS_EN > 0) && (OS_TASK_SW_HOOK_EN > 0)
void OSTaskSwHook (void)
{
#if OS_CPU_FPU_EN > 0
void *pblk;
#endif
#if OS_CPU_FPU_EN > 0 /* Save VFP context of preempted task */
if (OSRunning == OS_TRUE) { /* Don't save on OSStart()! */
if (OSTCBCur->OSTCBOpt & OS_TASK_OPT_SAVE_FP) { /* See if task used FP */
pblk = OSTCBCur->OSTCBExtPtr; /* Yes, Get pointer to FP storage area */
if (pblk != (void *)0) { /* Make sure we have storage */
OS_CPU_FP_Save(pblk); /* Save the VFP registers in block */
}
}
}
/* Restore VFP context of new task */
if (OSTCBHighRdy->OSTCBOpt & OS_TASK_OPT_SAVE_FP) { /* See if new task uses FP */
pblk = OSTCBHighRdy->OSTCBExtPtr; /* Yes, Get pointer to FP storage area */
if (pblk != (void *)0) { /* Make sure we have storage */
OS_CPU_FP_Restore(pblk); /* Get contents of VFP registers */
}
}
#endif
#if OS_APP_HOOKS_EN > 0
App_TaskSwHook();
#endif
}
#endif
/*
*********************************************************************************************************
* OS_TCBInit() HOOK
*
* Description: This function is called by OS_TCBInit() after setting up most of the TCB.
*
* Arguments : ptcb is a pointer to the TCB of the task being created.
*
* Note(s) : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void OSTCBInitHook (OS_TCB *ptcb)
{
#if OS_APP_HOOKS_EN > 0
App_TCBInitHook(ptcb);
#else
(void)ptcb; /* Prevent compiler warning */
#endif
}
#endif
/*
*********************************************************************************************************
* TICK HOOK
*
* Description: This function is called every tick.
*
* Arguments : none
*
* Note(s) : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/
#if (OS_CPU_HOOKS_EN > 0) && (OS_TIME_TICK_HOOK_EN > 0)
void OSTimeTickHook (void)
{
#if OS_APP_HOOKS_EN > 0
App_TimeTickHook();
#endif
#if OS_TMR_EN > 0
OSTmrCtr++;
if (OSTmrCtr >= (OS_TICKS_PER_SEC / OS_TMR_CFG_TICKS_PER_SEC)) {
OSTmrCtr = 0;
OSTmrSignal();
}
#endif
#if OS_CPU_ARM_DCC_EN > 0
OSDCC_Handler();
#endif
}
#endif
/*
*********************************************************************************************************
* INTERRUPT DISABLE TIME MEASUREMENT, START
*********************************************************************************************************
*/
#if OS_CPU_INT_DIS_MEAS_EN > 0
void OS_CPU_IntDisMeasInit (void)
{
OS_CPU_IntDisMeasNestingCtr = 0;
OS_CPU_IntDisMeasCntsEnter = 0;
OS_CPU_IntDisMeasCntsExit = 0;
OS_CPU_IntDisMeasCntsMax = 0;
OS_CPU_IntDisMeasCntsDelta = 0;
OS_CPU_IntDisMeasCntsOvrhd = 0;
OS_CPU_IntDisMeasStart(); /* Measure the overhead of the functions */
OS_CPU_IntDisMeasStop();
OS_CPU_IntDisMeasCntsOvrhd = OS_CPU_IntDisMeasCntsDelta;
}
void OS_CPU_IntDisMeasStart (void)
{
OS_CPU_IntDisMeasNestingCtr++;
if (OS_CPU_IntDisMeasNestingCtr == 1) { /* Only measure at the first nested level */
OS_CPU_IntDisMeasCntsEnter = OS_CPU_IntDisMeasTmrRd();
}
}
void OS_CPU_IntDisMeasStop (void)
{
OS_CPU_IntDisMeasNestingCtr--; /* Decrement nesting ctr */
if (OS_CPU_IntDisMeasNestingCtr == 0) {
OS_CPU_IntDisMeasCntsExit = OS_CPU_IntDisMeasTmrRd();
OS_CPU_IntDisMeasCntsDelta = OS_CPU_IntDisMeasCntsExit - OS_CPU_IntDisMeasCntsEnter;
if (OS_CPU_IntDisMeasCntsDelta > OS_CPU_IntDisMeasCntsOvrhd) { /* Ensure overhead < delta */
OS_CPU_IntDisMeasCntsDelta -= OS_CPU_IntDisMeasCntsOvrhd;
} else {
OS_CPU_IntDisMeasCntsDelta = OS_CPU_IntDisMeasCntsOvrhd;
}
if (OS_CPU_IntDisMeasCntsDelta > OS_CPU_IntDisMeasCntsMax) { /* Track MAXIMUM */
OS_CPU_IntDisMeasCntsMax = OS_CPU_IntDisMeasCntsDelta;
}
}
}
#endif
/*
*********************************************************************************************************
* INITIALIZE EXCEPTION VECTORS
*
* Description : This function initialize exception vectors to the default handlers.
*
* Arguments : None.
*********************************************************************************************************
*/
void OS_CPU_InitExceptVect (void)
{
(*(INT32U *)OS_CPU_ARM_EXCEPT_UNDEF_INSTR_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_UNDEF_INSTR_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptUndefInstrHndlr;
(*(INT32U *)OS_CPU_ARM_EXCEPT_SWI_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_SWI_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptSwiHndlr;
(*(INT32U *)OS_CPU_ARM_EXCEPT_PREFETCH_ABORT_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_PREFETCH_ABORT_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptPrefetchAbortHndlr;
(*(INT32U *)OS_CPU_ARM_EXCEPT_DATA_ABORT_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_DATA_ABORT_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptDataAbortHndlr;
(*(INT32U *)OS_CPU_ARM_EXCEPT_ADDR_ABORT_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_ADDR_ABORT_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptAddrAbortHndlr;
(*(INT32U *)OS_CPU_ARM_EXCEPT_IRQ_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_IRQ_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptIrqHndlr;
(*(INT32U *)OS_CPU_ARM_EXCEPT_FIQ_VECT_ADDR) = OS_CPU_ARM_INSTR_JUMP_TO_HANDLER;
(*(INT32U *)OS_CPU_ARM_EXCEPT_FIQ_HANDLER_ADDR) = (INT32U)OS_CPU_ARM_ExceptFiqHndlr;
}
/*
*********************************************************************************************************
* GET NUMBER OF FREE ENTRIES IN EXCEPTION STACK
*
* Description : This function computes the number of free entries in the exception stack.
*
* Arguments : None.
*
* Returns : The number of free entries in the exception stack.
*********************************************************************************************************
*/
INT32U OS_CPU_ExceptStkChk (void)
{
OS_STK *pchk;
INT32U nfree;
INT32U size;
nfree = 0;
size = OS_CPU_EXCEPT_STK_SIZE;
#if OS_STK_GROWTH == 1
pchk = &OS_CPU_ExceptStk[0];
while ((*pchk++ == (OS_STK)0) && (size > 0)) { /* Compute the number of zero entries on the stk */
nfree++;
size--;
}
#else
pchk = &OS_CPU_ExceptStk[OS_CPU_EXCEPT_STK_SIZE - 1];
while ((*pchk-- == (OS_STK)0) && (size > 0)) { /* Compute the number of zero entries on the stk */
nfree++;
size--;
}
#endif
return (nfree);
}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -