text: /*
  *********************************************************************************************************
  *                                              uC/OS-II
  *                                        The Real-Time Kernel
  *
  *                    Copyright 1992-2021 Silicon Laboratories Inc. www.silabs.com
  *
  *                                 SPDX-License-Identifier: APACHE-2.0
  *
  *               This software is subject to an open source license and is distributed by
  *                Silicon Laboratories Inc. pursuant to the terms of the Apache License,
  *                    Version 2.0 available at www.apache.org/licenses/LICENSE-2.0.
  *
  *********************************************************************************************************
  */
  
  
  /*
  *********************************************************************************************************
  *
  *                                   ATMEL  AVR32 AP7000 Specific code
  *
  * Filename : os_cpu_c.c
  * Version  : V2.93.01
  *********************************************************************************************************
  */
  
  #define   OS_CPU_GLOBALS
  #include  <ucos_ii.h>
  
  
  /*
  *********************************************************************************************************
  *                                          LOCAL VARIABLES
  *********************************************************************************************************
  */
  
  #if      (OS_VERSION >= 281) && (OS_TMR_EN > 0)
    static  INT16U  OSTmrCtr;
  #endif                                                                  /* #if (OS_VERSION >= 281) && (OS_TMR_EN > 0)               */
  
  /*
  **************************************************************************************************************
  *                                         STATUS REGISTER MASKS
  **************************************************************************************************************
  */
  
  #define  OS_CPU_SR_M0_MASK              0x00400000                      /* Status Register, Supervisor Execution Mode Mask          */
  
  /*
  *********************************************************************************************************
  *                                       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_VERSION >= 281) && (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)
  {
  }
  #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_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_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_APP_HOOKS_EN > 0
      App_TaskIdleHook();
  #endif
  }
  #endif
  
  /*
  *********************************************************************************************************
  *                                            TASK RETURN HOOK
  *
  * Description: This function is called if a task accidentally returns.  In other words, a task should
  *              either be an infinite loop or delete itself when done.
  *
  * Arguments  : ptcb      is a pointer to the task control block of the task that is returning.
  *
  * Note(s)    : none
  *********************************************************************************************************
  */
  
  #if OS_CPU_HOOKS_EN > 0u
  void  OSTaskReturnHook (OS_TCB  *ptcb)
  {
  #if OS_APP_HOOKS_EN > 0u
      App_TaskReturnHook(ptcb);
  #else
      (void)ptcb;
  #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 the
  *                            highest valid address on the stack.
  *
  *              opt           specifies options that can be used to alter the behavior of OSTaskStkInit().
  *                            (see uCOS_II.H for OS_TASK_OPT_???).
  *
  * 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) Avoid AVR32Studio warning "Target request failed: cannot access memory at address #" at debug mode.
  *
  *              2) Prevent AVR32Studio prematurely exiting from debug mode at OSCtxRestore due to invalid memory access.
  **********************************************************************************************************
  */
  
  OS_STK  *OSTaskStkInit (void (*task)(void *pd), void *p_arg, OS_STK *ptos, INT16U opt)
  {
      OS_STK *stk;
  
  
      (void)opt;                                                          /* 'opt' is not used, prevent warning                       */
  
       stk   =          ptos;
  
  #if __GNUC__
      *stk-- = (INT32U) 0x00000000;                                       /* R14/LR (reset vector for GNU C) (note 1)                 */
  #else
      *stk-- = (INT32U) 0x14141414;                                       /* R14/LR                                                   */
  #endif
      *stk-- = (INT32U) 0xFF0000FF;                                       /* R0                                                       */
      *stk-- = (INT32U) 0x01010101;                                       /* R1                                                       */
      *stk-- = (INT32U) 0x02020202;                                       /* R2                                                       */
      *stk-- = (INT32U) 0x03030303;                                       /* R3                                                       */
      *stk-- = (INT32U) 0x04040404;                                       /* R4                                                       */
      *stk-- = (INT32U) 0x05050505;                                       /* R5                                                       */
      *stk-- = (INT32U) 0x06060606;                                       /* R6                                                       */
  #if __GNUC__
      *stk-- = (INT32U) 0x00000000;                                       /* R7 (note 2)                                              */
  #else
      *stk-- = (INT32U) 0x07070707;                                       /* R7                                                       */
  #endif
      *stk-- = (INT32U) 0x08080808;                                       /* R8                                                       */
      *stk-- = (INT32U) 0x09090909;                                       /* R9                                                       */
      *stk-- = (INT32U) 0x10101010;                                       /* R10                                                      */
      *stk-- = (INT32U) 0x11111111;                                       /* R11                                                      */
      *stk-- = (INT32U) p_arg;                                            /* R12                                                      */
  
      *stk-- = (INT32U) task;                                             /* R15/PC                                                   */
      *stk   = (INT32U) OS_CPU_SR_M0_MASK;                                /* SR: Supervisor 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_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_VERSION >= 281) && (OS_TMR_EN > 0)
      OSTmrCtr++;
      if (OSTmrCtr >= (OS_TICKS_PER_SEC / OS_TMR_CFG_TICKS_PER_SEC)) {
          OSTmrCtr = 0;
          OSTmrSignal();
      }
  #endif
  }
  #endif
  
  
  
  /*
  *********************************************************************************************************
  *                                    INTERRUPT LEVEL CONTEXT SWITCH
  *
  * Description: This function is called by OSIntExit() to perform a context switch from an ISR.
  *
  * Arguments  : none
  *
  * Note(s)    : 1) OSIntCtxSw() MUST:
  *                      a) Call OSTaskSwHook() then,
  *                      b) Set OSTCBCur = OSTCBHighRdy,
  *                      c) Set OSPrioCur = OSPrioHighRdy,
  *                      d) Switch to the highest priority task.
  *********************************************************************************************************
  */
  
  void  OSIntCtxSw (void)
  {
      OSTaskSwHook();
  
      OSTCBCur  =  OSTCBHighRdy;
      OSPrioCur =  OSPrioHighRdy;
  
      OSIntCtxRestore(OSTCBHighRdy->OSTCBStkPtr);
  }
  
  
  /*
  *********************************************************************************************************
  *                              START HIGHEST PRIORITY TASK READY-TO-RUN
  *
  * Description: This function is called by OSStart() to start the highest priority task that was created
  *              by your application before calling OSStart().
  *
  * Arguments  : none
  *
  * Note(s)    : 1) OSStartHighRdy() MUST:
  *                      a) Call OSTaskSwHook() then,
  *                      b) Set OSRunning to TRUE,
  *                      c) Switch to the highest priority task.
  *********************************************************************************************************
  */
  
  void  OSStartHighRdy (void)
  {
      OSTaskSwHook();
      OSRunning =  1;
      OSCtxRestore(OSTCBHighRdy->OSTCBStkPtr);
  }
  