/*
*********************************************************************************************************
*                                              uC/OS-III
*                                        The Real-Time Kernel
*
*                    Copyright 2009-2021 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.
*
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*
*                                             ARMv7-A Port
*
* File    : os_cpu_c.c
* Version : V3.08.01
*********************************************************************************************************
* For     : ARMv7-A Cortex-A
* Mode    : ARM or Thumb
*********************************************************************************************************
*/

#define   OS_CPU_GLOBALS

#ifdef VSC_INCLUDE_SOURCE_FILE_NAMES
const  CPU_CHAR  *os_cpu_c__c = "$Id: $";
#endif

/*
*********************************************************************************************************
*                                             INCLUDE FILES
*********************************************************************************************************
*/

#include  "../../../Source/os.h"
#include  "os_cpu.h"


#ifdef __cplusplus
extern  "C" {
#endif


/*
*********************************************************************************************************
*                                           LOCAL CONSTANTS
*
* Note(s) : 1) ARM_MODE_ARM       is the CPSR bit mask for ARM Mode
*           2) ARM_MODE_THUMB     is the CPSR bit mask for THUMB Mode
*           3) ARM_SVC_MODE_THUMB is the CPSR bit mask for SVC MODE + THUMB Mode
*           4) ARM_SVC_MODE_ARM   is the CPSR bit mask for SVC MODE + ARM Mode
*********************************************************************************************************
*/

#if (CPU_CFG_ENDIAN_TYPE == CPU_ENDIAN_TYPE_LITTLE)
#define  ARM_MODE_ARM           0x00000000u
#define  ARM_MODE_THUMB         0x00000020u
#else                                                           /* Set bit 9 in big-endian mode.                        */
#define  ARM_MODE_ARM           0x00000200u
#define  ARM_MODE_THUMB         0x00000220u
#endif

#define  ARM_SVC_MODE_THUMB    (0x00000013u + ARM_MODE_THUMB)
#define  ARM_SVC_MODE_ARM      (0x00000013u + ARM_MODE_ARM)


/*
*********************************************************************************************************
*                                           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)    : None.
*********************************************************************************************************
*/

void  OSIdleTaskHook (void)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppIdleTaskHookPtr != (OS_APP_HOOK_VOID)0) {
        (*OS_AppIdleTaskHookPtr)();
    }
#endif
}


/*
*********************************************************************************************************
*                                       OS INITIALIZATION HOOK
*
* Description: This function is called by OSInit() at the beginning of OSInit().
*
* Arguments  : None.
*
* Note(s)    : None.
*********************************************************************************************************
*/

void  OSInitHook (void)
{
    CPU_STK_SIZE   i;
    CPU_STK       *p_stk;


    p_stk = OSCfg_ISRStkBasePtr;                            /* Clear the ISR stack                                    */
    for (i = 0u; i < OSCfg_ISRStkSize; i++) {
        *p_stk++ = (CPU_STK)0u;
    }
    OS_CPU_ExceptStkBase = (CPU_STK *)(OSCfg_ISRStkBasePtr + OSCfg_ISRStkSize - 1u);

    OS_CPU_ARM_DRegCnt = OS_CPU_ARM_DRegCntGet();
}


/*
*********************************************************************************************************
*                                           REDZONE HIT HOOK
*
* Description: This function is called when a task's stack overflowed.
*
* Arguments  : p_tcb        Pointer to the task control block of the offending task. NULL if ISR.
*
* Note(s)    : None.
*********************************************************************************************************
*/
#if (OS_CFG_TASK_STK_REDZONE_EN > 0u)
void  OSRedzoneHitHook (OS_TCB  *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppRedzoneHitHookPtr != (OS_APP_HOOK_TCB)0) {
        (*OS_AppRedzoneHitHookPtr)(p_tcb);
    } else {
        CPU_SW_EXCEPTION(;);
    }
#else
    (void)p_tcb;                                                /* Prevent compiler warning                             */
    CPU_SW_EXCEPTION(;);
#endif
}
#endif


/*
*********************************************************************************************************
*                                         STATISTIC TASK HOOK
*
* Description: This function is called every second by uC/OS-III's statistics task.  This allows your
*              application to add functionality to the statistics task.
*
* Arguments  : None.
*
* Note(s)    : None.
*********************************************************************************************************
*/

void  OSStatTaskHook (void)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppStatTaskHookPtr != (OS_APP_HOOK_VOID)0) {
        (*OS_AppStatTaskHookPtr)();
    }
#endif
}


/*
*********************************************************************************************************
*                                          TASK CREATION HOOK
*
* Description: This function is called when a task is created.
*
* Arguments  : p_tcb        Pointer to the task control block of the task being created.
*
* Note(s)    : None.
*********************************************************************************************************
*/

void  OSTaskCreateHook (OS_TCB  *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppTaskCreateHookPtr != (OS_APP_HOOK_TCB)0) {
        (*OS_AppTaskCreateHookPtr)(p_tcb);
    }
#else
    (void)p_tcb;                                            /* Prevent compiler warning                               */
#endif
}


/*
*********************************************************************************************************
*                                           TASK DELETION HOOK
*
* Description: This function is called when a task is deleted.
*
* Arguments  : p_tcb        Pointer to the task control block of the task being deleted.
*
* Note(s)    : None.
*********************************************************************************************************
*/

void  OSTaskDelHook (OS_TCB  *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppTaskDelHookPtr != (OS_APP_HOOK_TCB)0) {
        (*OS_AppTaskDelHookPtr)(p_tcb);
    }
#else
    (void)p_tcb;                                            /* Prevent compiler warning                               */
#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  : p_tcb        Pointer to the task control block of the task that is returning.
*
* Note(s)    : None.
*********************************************************************************************************
*/

void  OSTaskReturnHook (OS_TCB  *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppTaskReturnHookPtr != (OS_APP_HOOK_TCB)0) {
        (*OS_AppTaskReturnHookPtr)(p_tcb);
    }
#else
    (void)p_tcb;                                            /* Prevent compiler warning                               */
#endif
}


/*
**********************************************************************************************************
*                                       INITIALIZE A TASK'S STACK
*
* Description: This function is called by OS_Task_Create() or OSTaskCreateExt() to initialize the stack
*              frame of the task being created. This function is highly processor specific.
*
* Arguments  : p_task       Pointer to the task entry point address.
*
*              p_arg        Pointer to a user supplied data area that will be passed to the task
*                               when the task first executes.
*
*              p_stk_base   Pointer to the base address of the stack.
*
*              stk_size     Size of the stack, in number of CPU_STK elements.
*
*              opt          Options used to alter the behavior of OS_Task_StkInit().
*                            (see OS.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 task starts executing.
*
*              2) All tasks run in SVC mode.
**********************************************************************************************************
*/

CPU_STK  *OSTaskStkInit (OS_TASK_PTR    p_task,
                         void          *p_arg,
                         CPU_STK       *p_stk_base,
                         CPU_STK       *p_stk_limit,
                         CPU_STK_SIZE   stk_size,
                         OS_OPT         opt)
{
    CPU_STK    *p_stk;
    CPU_STK     task_addr;
    CPU_INT32U  i;
    CPU_INT32U  fpu_reg_cnt;


    (void)opt;                                                  /* Prevent compiler warning                             */
    (void)p_stk_limit;

    p_stk     = &p_stk_base[stk_size];                          /* Load stack pointer                                   */

    p_stk     = (CPU_STK *)((CPU_STK)p_stk & ~(CPU_CFG_STK_ALIGN_BYTES - 1u)); /* Align stack pointer.                  */

    task_addr = (CPU_STK)p_task & ~1u;                          /* Mask off lower bit in case task is thumb mode        */

    *--p_stk  = (CPU_STK)task_addr;                             /* Entry Point                                          */
    *--p_stk  = (CPU_STK)OS_TaskReturn;                         /* Reg R14 (LR)                                         */
    *--p_stk  = (CPU_STK)0x12121212u;                           /* Reg R12                                              */
    *--p_stk  = (CPU_STK)0x11111111u;                           /* Reg R11                                              */
    *--p_stk  = (CPU_STK)0x10101010u;                           /* Reg R10                                              */
    *--p_stk  = (CPU_STK)0x09090909u;                           /* Reg R9                                               */
    *--p_stk  = (CPU_STK)0x08080808u;                           /* Reg R8                                               */
    *--p_stk  = (CPU_STK)0x07070707u;                           /* Reg R7                                               */
    *--p_stk  = (CPU_STK)0x06060606u;                           /* Reg R6                                               */
    *--p_stk  = (CPU_STK)0x05050505u;                           /* Reg R5                                               */
    *--p_stk  = (CPU_STK)0x04040404u;                           /* Reg R4                                               */
    *--p_stk  = (CPU_STK)0x03030303u;                           /* Reg R3                                               */
    *--p_stk  = (CPU_STK)0x02020202u;                           /* Reg R2                                               */
    *--p_stk  = (CPU_STK)0x01010101u;                           /* Reg R1                                               */
    *--p_stk  = (CPU_STK)p_arg;                                 /* Reg R0 : argument                                    */

    if (((CPU_STK)p_task & 0x01u) == 0x01u) {                   /* See if task runs in Thumb or ARM mode                */
       *--p_stk = (CPU_STK)ARM_SVC_MODE_THUMB;                  /* CPSR  (Enable IRQ and FIQ interrupts, THUMB-mode)    */
    } else {
       *--p_stk = (CPU_STK)ARM_SVC_MODE_ARM;                    /* CPSR  (Enable IRQ and FIQ interrupts, ARM-mode)      */
    }

    fpu_reg_cnt = OS_CPU_ARM_DRegCntGet();

    if (fpu_reg_cnt != 0u) {
        *--p_stk = (CPU_STK)0;                                   /* Initialize Floating point status & control register  */
                                                                 /* Initialize general-purpose Floating point registers  */
         for (i = 0u; i < fpu_reg_cnt * 2u; i++) {
             *--p_stk = (CPU_STK)0;
         }

        *--p_stk = (CPU_STK)(0x40000000);                        /* Initialize Floating-Point Exception Register (Enable)*/
    }

    return (p_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 'OSTCBHighRdyPtr' points to the TCB of the task
*                 that will be 'switched in' (i.e. the highest priority task) and, 'OSTCBCurPtr' points
*                 to the task being switched out (i.e. the preempted task).
*********************************************************************************************************
*/

void  OSTaskSwHook (void)
{
#if OS_CFG_TASK_PROFILE_EN > 0u
    CPU_TS  ts;
#endif
#ifdef  CPU_CFG_INT_DIS_MEAS_EN
    CPU_TS  int_dis_time;
#endif
#if (OS_CFG_TASK_STK_REDZONE_EN > 0u)
    CPU_BOOLEAN  stk_status;
#endif


#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppTaskSwHookPtr != (OS_APP_HOOK_VOID)0) {
        (*OS_AppTaskSwHookPtr)();
    }
#endif

    OS_TRACE_TASK_SWITCHED_IN(OSTCBHighRdyPtr);

#if OS_CFG_TASK_PROFILE_EN > 0u
    ts = OS_TS_GET();
    if (OSTCBCurPtr != OSTCBHighRdyPtr) {
        OSTCBCurPtr->CyclesDelta  = ts - OSTCBCurPtr->CyclesStart;
        OSTCBCurPtr->CyclesTotal += (OS_CYCLES)OSTCBCurPtr->CyclesDelta;
    }

    OSTCBHighRdyPtr->CyclesStart = ts;
#endif

#ifdef  CPU_CFG_INT_DIS_MEAS_EN
    int_dis_time = CPU_IntDisMeasMaxCurReset();                   /* Keep track of per-task interrupt disable time    */
    if (OSTCBCurPtr->IntDisTimeMax < int_dis_time) {
        OSTCBCurPtr->IntDisTimeMax = int_dis_time;
    }
#endif

#if OS_CFG_SCHED_LOCK_TIME_MEAS_EN > 0u
    if (OSTCBCurPtr->SchedLockTimeMax < OSSchedLockTimeMaxCur) {  /* Keep track of per-task scheduler lock time       */
        OSTCBCurPtr->SchedLockTimeMax = OSSchedLockTimeMaxCur;
    }
    OSSchedLockTimeMaxCur = (CPU_TS)0;                            /* Reset the per-task value                         */
#endif

#if (OS_CFG_TASK_STK_REDZONE_EN > 0u)
                                                                /* Check if stack overflowed.                           */
    stk_status = OSTaskStkRedzoneChk((OS_TCB *)0);
    if (stk_status != OS_TRUE) {
        OSRedzoneHitHook(OSTCBCurPtr);
    }
#endif
}


/*
*********************************************************************************************************
*                                              TICK HOOK
*
* Description: This function is called every tick.
*
* Arguments  : None.
*
* Note(s)    : 1) This function is assumed to be called from the Tick ISR.
*********************************************************************************************************
*/

void  OSTimeTickHook (void)
{
#if OS_CFG_APP_HOOKS_EN > 0u
    if (OS_AppTimeTickHookPtr != (OS_APP_HOOK_VOID)0) {
        (*OS_AppTimeTickHookPtr)();
    }
#endif
}

#ifdef __cplusplus
}
#endif
