/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*
*                             (c) Copyright 1992-2006, Micrium, Weston, FL
*                                          All Rights Reserved
*
*                                           Generic ARM Port
*
* File      : OS_CPU_C.C
* Version   : V1.70
* By        : Jean J. Labrosse
*
* For       : ARM7 or ARM9
* Mode      : ARM or Thumb
* Toolchain : IAR's EWARM V4.11a and higher
*********************************************************************************************************
*/

#define  OS_CPU_GLOBALS
#include <ucos_ii.h>

#if      OS_VIEW_MODULE > 0
#include <OS_VIEWc.H>
#include <OS_VIEW.H>
#endif

#define  ARM_MODE_ARM           0x00000000
#define  ARM_MODE_THUMB         0x00000020

#define  ARM_SVC_MODE_THUMB    (0x00000013L + ARM_MODE_THUMB)
#define  ARM_SVC_MODE_ARM      (0x00000013L + ARM_MODE_ARM)

/*
*********************************************************************************************************
*                                          LOCAL VARIABLES
*********************************************************************************************************
*/

#if OS_TMR_EN > 0
static  INT16U  OSTmrCtr;
#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
}
#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_VIEW_MODULE > 0
    OSView_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)
{
    (void)ptcb;                        /* Prevent compiler warning                                     */
}
#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)
{
}
#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)
{
}
#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
*
* 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_VIEW_MODULE > 0
    OSView_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)
{
    (void)ptcb;                                            /* Prevent Compiler warning                 */
}
#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_VIEW_MODULE > 0
    OSView_TickHook();
#endif

#if OS_TMR_EN > 0
    OSTmrCtr++;
    if (OSTmrCtr >= (OS_TICKS_PER_SEC / OS_TMR_CFG_TICKS_PER_SEC)) {
        OSTmrCtr = 0;
        OSTmrSignal();
    }
#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
