pinebuds/rtos/rtx5/rtx_kernel.c

/*
 * Copyright (c) 2013-2019 Arm Limited. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * -----------------------------------------------------------------------------
 *
 * Project:     CMSIS-RTOS RTX
 * Title:       Kernel functions
 *
 * -----------------------------------------------------------------------------
 */

#include "hal_timer.h"
#include "hal_trace.h"
#include "os_tick.h"
#include "rtx_lib.h"

//  OS Runtime Information
osRtxInfo_t osRtxInfo __attribute__((section(".data.os"))) =
    // lint -e{785} "Initialize only OS ID, OS Version and Kernel State"
    {.os_id = osRtxKernelId,
     .version = osRtxVersionKernel,
     .kernel.state = osRtxKernelInactive};

#define OS_BSS_LOC __attribute__((section(".bss.os")))
OS_BSS_LOC static uint32_t systick_lock_val;
OS_BSS_LOC static uint32_t systick_lock_ts;

//  ==== Helper functions ====

/// Block Kernel (disable: thread switching, time tick, post ISR processing).
static void KernelBlock(void) {

  OS_Tick_Disable();

  osRtxInfo.kernel.blocked = 1U;
  __DSB();

  if (GetPendSV() != 0U) {
    ClrPendSV();
    osRtxInfo.kernel.pendSV = 1U;
  }
}

/// Unblock Kernel
static void KernelUnblock(void) {

  osRtxInfo.kernel.blocked = 0U;
  __DSB();

  if (osRtxInfo.kernel.pendSV != 0U) {
    osRtxInfo.kernel.pendSV = 0U;
    SetPendSV();
  }

  OS_Tick_Enable();
}

//  ==== Service Calls ====

/// Initialize the RTOS Kernel.
/// \note API identical to osKernelInitialize
static osStatus_t svcRtxKernelInitialize(void) {

  if (osRtxInfo.kernel.state == osRtxKernelReady) {
    EvrRtxKernelInitialized();
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return osOK;
  }
  if (osRtxInfo.kernel.state != osRtxKernelInactive) {
    EvrRtxKernelError((int32_t)osError);
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return osError;
  }

#if (DOMAIN_NS == 1)
  // Initialize Secure Process Stack
  if (TZ_InitContextSystem_S() == 0U) {
    EvrRtxKernelError(osRtxErrorTZ_InitContext_S);
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return osError;
  }
#endif

  // Initialize osRtxInfo
  memset((uint8_t *)&osRtxInfo + offsetof(osRtxInfo_t, kernel), 0,
         sizeof(osRtxInfo) - offsetof(osRtxInfo_t, kernel));

  osRtxInfo.isr_queue.data = osRtxConfig.isr_queue.data;
  osRtxInfo.isr_queue.max = osRtxConfig.isr_queue.max;

  osRtxInfo.thread.robin.timeout = osRtxConfig.robin_timeout;

  // Initialize Memory Pools (Variable Block Size)
  if (osRtxMemoryInit(osRtxConfig.mem.common_addr,
                      osRtxConfig.mem.common_size) != 0U) {
    osRtxInfo.mem.common = osRtxConfig.mem.common_addr;
  }
  if (osRtxMemoryInit(osRtxConfig.mem.stack_addr, osRtxConfig.mem.stack_size) !=
      0U) {
    osRtxInfo.mem.stack = osRtxConfig.mem.stack_addr;
  } else {
    osRtxInfo.mem.stack = osRtxInfo.mem.common;
  }
  if (osRtxMemoryInit(osRtxConfig.mem.mp_data_addr,
                      osRtxConfig.mem.mp_data_size) != 0U) {
    osRtxInfo.mem.mp_data = osRtxConfig.mem.mp_data_addr;
  } else {
    osRtxInfo.mem.mp_data = osRtxInfo.mem.common;
  }
  if (osRtxMemoryInit(osRtxConfig.mem.mq_data_addr,
                      osRtxConfig.mem.mq_data_size) != 0U) {
    osRtxInfo.mem.mq_data = osRtxConfig.mem.mq_data_addr;
  } else {
    osRtxInfo.mem.mq_data = osRtxInfo.mem.common;
  }

  // Initialize Memory Pools (Fixed Block Size)
  if (osRtxConfig.mpi.stack != NULL) {
    (void)osRtxMemoryPoolInit(
        osRtxConfig.mpi.stack, osRtxConfig.mpi.stack->max_blocks,
        osRtxConfig.mpi.stack->block_size, osRtxConfig.mpi.stack->block_base);
    osRtxInfo.mpi.stack = osRtxConfig.mpi.stack;
  }
  if (osRtxConfig.mpi.thread != NULL) {
    (void)osRtxMemoryPoolInit(
        osRtxConfig.mpi.thread, osRtxConfig.mpi.thread->max_blocks,
        osRtxConfig.mpi.thread->block_size, osRtxConfig.mpi.thread->block_base);
    osRtxInfo.mpi.thread = osRtxConfig.mpi.thread;
  }
  if (osRtxConfig.mpi.timer != NULL) {
    (void)osRtxMemoryPoolInit(
        osRtxConfig.mpi.timer, osRtxConfig.mpi.timer->max_blocks,
        osRtxConfig.mpi.timer->block_size, osRtxConfig.mpi.timer->block_base);
    osRtxInfo.mpi.timer = osRtxConfig.mpi.timer;
  }
  if (osRtxConfig.mpi.event_flags != NULL) {
    (void)osRtxMemoryPoolInit(osRtxConfig.mpi.event_flags,
                              osRtxConfig.mpi.event_flags->max_blocks,
                              osRtxConfig.mpi.event_flags->block_size,
                              osRtxConfig.mpi.event_flags->block_base);
    osRtxInfo.mpi.event_flags = osRtxConfig.mpi.event_flags;
  }
  if (osRtxConfig.mpi.mutex != NULL) {
    (void)osRtxMemoryPoolInit(
        osRtxConfig.mpi.mutex, osRtxConfig.mpi.mutex->max_blocks,
        osRtxConfig.mpi.mutex->block_size, osRtxConfig.mpi.mutex->block_base);
    osRtxInfo.mpi.mutex = osRtxConfig.mpi.mutex;
  }
  if (osRtxConfig.mpi.semaphore != NULL) {
    (void)osRtxMemoryPoolInit(osRtxConfig.mpi.semaphore,
                              osRtxConfig.mpi.semaphore->max_blocks,
                              osRtxConfig.mpi.semaphore->block_size,
                              osRtxConfig.mpi.semaphore->block_base);
    osRtxInfo.mpi.semaphore = osRtxConfig.mpi.semaphore;
  }
  if (osRtxConfig.mpi.memory_pool != NULL) {
    (void)osRtxMemoryPoolInit(osRtxConfig.mpi.memory_pool,
                              osRtxConfig.mpi.memory_pool->max_blocks,
                              osRtxConfig.mpi.memory_pool->block_size,
                              osRtxConfig.mpi.memory_pool->block_base);
    osRtxInfo.mpi.memory_pool = osRtxConfig.mpi.memory_pool;
  }
  if (osRtxConfig.mpi.message_queue != NULL) {
    (void)osRtxMemoryPoolInit(osRtxConfig.mpi.message_queue,
                              osRtxConfig.mpi.message_queue->max_blocks,
                              osRtxConfig.mpi.message_queue->block_size,
                              osRtxConfig.mpi.message_queue->block_base);
    osRtxInfo.mpi.message_queue = osRtxConfig.mpi.message_queue;
  }

  osRtxInfo.kernel.state = osRtxKernelReady;

  EvrRtxKernelInitialized();

  return osOK;
}

///  Get RTOS Kernel Information.
/// \note API identical to osKernelGetInfo
static osStatus_t svcRtxKernelGetInfo(osVersion_t *version, char *id_buf,
                                      uint32_t id_size) {
  uint32_t size;

  if (version != NULL) {
    version->api = osRtxVersionAPI;
    version->kernel = osRtxVersionKernel;
  }

  if ((id_buf != NULL) && (id_size != 0U)) {
    if (id_size > sizeof(osRtxKernelId)) {
      size = sizeof(osRtxKernelId);
    } else {
      size = id_size;
    }
    memcpy(id_buf, osRtxKernelId, size);
  }

  EvrRtxKernelInfoRetrieved(version, id_buf, id_size);

  return osOK;
}

/// Get the current RTOS Kernel state.
/// \note API identical to osKernelGetState
static osKernelState_t svcRtxKernelGetState(void) {
  osKernelState_t state = osRtxKernelState();
  EvrRtxKernelGetState(state);
  return state;
}

/// Start the RTOS Kernel scheduler.
/// \note API identical to osKernelStart
static osStatus_t svcRtxKernelStart(void) {
  os_thread_t *thread;

  if (osRtxInfo.kernel.state != osRtxKernelReady) {
    EvrRtxKernelError(osRtxErrorKernelNotReady);
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return osError;
  }

  // Thread startup (Idle and Timer Thread)
  if (!osRtxThreadStartup()) {
    EvrRtxKernelError((int32_t)osError);
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return osError;
  }

  // Setup SVC and PendSV System Service Calls
  SVC_Setup();

  // Setup RTOS Tick
  if (OS_Tick_Setup(osRtxConfig.tick_freq, OS_TICK_HANDLER) != 0) {
    EvrRtxKernelError((int32_t)osError);
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return osError;
  }
  osRtxInfo.tick_irqn = OS_Tick_GetIRQn();

  // Enable RTOS Tick
  OS_Tick_Enable();

  // Switch to Ready Thread with highest Priority
  thread = osRtxThreadListGet(&osRtxInfo.thread.ready);
  osRtxThreadSwitch(thread);

  if ((osRtxConfig.flags & osRtxConfigPrivilegedMode) != 0U) {
    // Privileged Thread mode & PSP
    __set_CONTROL(0x02U);
  } else {
    // Unprivileged Thread mode & PSP
    __set_CONTROL(0x03U);
  }

  osRtxInfo.kernel.state = osRtxKernelRunning;

  EvrRtxKernelStarted();

  return osOK;
}

/// Lock the RTOS Kernel scheduler.
/// \note API identical to osKernelLock
static int32_t svcRtxKernelLock(void) {
  int32_t lock;

  switch (osRtxInfo.kernel.state) {
  case osRtxKernelRunning:
    osRtxInfo.kernel.state = osRtxKernelLocked;
    EvrRtxKernelLocked(0);
    lock = 0;
    break;
  case osRtxKernelLocked:
    EvrRtxKernelLocked(1);
    lock = 1;
    break;
  default:
    EvrRtxKernelError((int32_t)osError);
    lock = (int32_t)osError;
    break;
  }
  return lock;
}

/// Unlock the RTOS Kernel scheduler.
/// \note API identical to osKernelUnlock
static int32_t svcRtxKernelUnlock(void) {
  int32_t lock;

  switch (osRtxInfo.kernel.state) {
  case osRtxKernelRunning:
    EvrRtxKernelUnlocked(0);
    lock = 0;
    break;
  case osRtxKernelLocked:
    osRtxInfo.kernel.state = osRtxKernelRunning;
    EvrRtxKernelUnlocked(1);
    lock = 1;
    break;
  default:
    EvrRtxKernelError((int32_t)osError);
    lock = (int32_t)osError;
    break;
  }
  return lock;
}

/// Restore the RTOS Kernel scheduler lock state.
/// \note API identical to osKernelRestoreLock
static int32_t svcRtxKernelRestoreLock(int32_t lock) {
  int32_t lock_new;

  switch (osRtxInfo.kernel.state) {
  case osRtxKernelRunning:
  case osRtxKernelLocked:
    switch (lock) {
    case 0:
      osRtxInfo.kernel.state = osRtxKernelRunning;
      EvrRtxKernelLockRestored(0);
      lock_new = 0;
      break;
    case 1:
      osRtxInfo.kernel.state = osRtxKernelLocked;
      EvrRtxKernelLockRestored(1);
      lock_new = 1;
      break;
    default:
      EvrRtxKernelError((int32_t)osError);
      lock_new = (int32_t)osError;
      break;
    }
    break;
  default:
    EvrRtxKernelError((int32_t)osError);
    lock_new = (int32_t)osError;
    break;
  }
  return lock_new;
}

/// Suspend the RTOS Kernel scheduler.
/// \note API identical to osKernelSuspend
static uint32_t svcRtxKernelSuspend(void) {
  const os_thread_t *thread;
  const os_timer_t *timer;
  uint32_t delay;

  if (osRtxInfo.kernel.state != osRtxKernelRunning) {
    EvrRtxKernelError(osRtxErrorKernelNotRunning);
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return 0U;
  }

  KernelBlock();

  systick_lock_val = OS_Tick_GetInterval() - 1 - OS_Tick_GetCount();
  systick_lock_ts = hal_sys_timer_get();

  delay = osWaitForever;

  // Check Thread Delay list
  thread = osRtxInfo.thread.delay_list;
  if (thread != NULL) {
    delay = thread->delay;
  }

  // Check Active Timer list
  timer = osRtxInfo.timer.list;
  if (timer != NULL) {
    if (timer->tick < delay) {
      delay = timer->tick;
    }
  }

  osRtxInfo.kernel.state = osRtxKernelSuspended;

  EvrRtxKernelSuspended(delay);

  return delay;
}

/// Resume the RTOS Kernel scheduler.
/// \note API identical to osKernelResume
static void svcRtxKernelResume(uint32_t sleep_ticks) {
  os_thread_t *thread;
  os_timer_t *timer;
  uint32_t delay;
  uint32_t ticks;

  uint32_t resume_ts;
  uint32_t tick_interval;
  uint32_t sysclk_remain;
  uint32_t delta_clk;
  uint32_t sleep_clk;

  if (osRtxInfo.kernel.state != osRtxKernelSuspended) {
    EvrRtxKernelResumed();
    // lint -e{904} "Return statement before end of function" [MISRA Note 1]
    return;
  }

  tick_interval = OS_Tick_GetInterval();
  resume_ts = hal_sys_timer_get();
  sleep_clk = (resume_ts - systick_lock_ts) *
              (OS_CLOCK_NOMINAL / CONFIG_SYSTICK_HZ_NOMINAL);
  if (systick_lock_val == 0) {
    sleep_ticks = sleep_clk / tick_interval;
    sysclk_remain = sleep_clk % tick_interval;
  } else if (sleep_clk >= systick_lock_val) {
    delta_clk = sleep_clk - systick_lock_val;
    sleep_ticks = delta_clk / tick_interval + 1;
    sysclk_remain = tick_interval - delta_clk % tick_interval;
  } else {
    sleep_ticks = 0;
    sysclk_remain = systick_lock_val - sleep_clk;
  }
#if __RTX_CPU_STATISTICS__
  osRtxInfo.thread.run.curr->rtime += sleep_ticks;
#endif
  osRtxInfo.kernel.tick += sleep_ticks;

  // Process Thread Delay list
  thread = osRtxInfo.thread.delay_list;
  if (thread != NULL) {
    delay = sleep_ticks;
    do {
      if (delay >= thread->delay) {
        delay -= thread->delay;
        thread->delay = 1U;
        osRtxThreadDelayTick();
        thread = osRtxInfo.thread.delay_list;
      } else {
        thread->delay -= delay;
        delay = 0U;
      }
    } while ((thread != NULL) && (delay != 0U));
  }

  // Process Active Timer list
  timer = osRtxInfo.timer.list;
  if (timer != NULL) {
    ticks = sleep_ticks;
    do {
      if (ticks >= timer->tick) {
        ticks -= timer->tick;
        timer->tick = 1U;
        osRtxInfo.timer.tick();
        timer = osRtxInfo.timer.list;
      } else {
        timer->tick -= ticks;
        ticks = 0U;
      }
    } while ((timer != NULL) && (ticks != 0U));
  }

  osRtxInfo.kernel.state = osRtxKernelRunning;

  osRtxThreadDispatch(NULL);

  if (sysclk_remain == tick_interval) {
    sysclk_remain = 0;
  }
  if (sysclk_remain) {
    SysTick->LOAD = sysclk_remain;
    SysTick->VAL = 0;
    SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk;
    while (SysTick->VAL == 0)
      ;
    SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
    SysTick->LOAD = tick_interval - 1;
  } else
    SysTick->VAL = 0;

#if defined(DEBUG_SLEEP) && (DEBUG_SLEEP >= 1)
  if (sleep_clk > 0) {
    TRACE(7, "[%u/0x%X][%2u/%u] resume: suspend tick:%u, sleep_clk=%u ticks=%u",
          TICKS_TO_MS(hal_sys_timer_get()), hal_sys_timer_get(), sysclk_remain,
          SysTick->VAL, systick_lock_val, sleep_clk, sleep_ticks);
  }
#endif

  KernelUnblock();

  EvrRtxKernelResumed();
}

/// Get the RTOS kernel tick count.
/// \note API identical to osKernelGetTickCount
static uint32_t svcRtxKernelGetTickCount(void) {
  EvrRtxKernelGetTickCount(osRtxInfo.kernel.tick);
  return osRtxInfo.kernel.tick;
}

/// Get the RTOS kernel tick frequency.
/// \note API identical to osKernelGetTickFreq
static uint32_t svcRtxKernelGetTickFreq(void) {
  EvrRtxKernelGetTickFreq(osRtxConfig.tick_freq);
  return osRtxConfig.tick_freq;
}

/// Get the RTOS kernel system timer count.
/// \note API identical to osKernelGetSysTimerCount
static uint32_t svcRtxKernelGetSysTimerCount(void) {
  uint32_t tick;
  uint32_t count;

  tick = (uint32_t)osRtxInfo.kernel.tick;
  count = OS_Tick_GetCount();
  if (OS_Tick_GetOverflow() != 0U) {
    count = OS_Tick_GetCount();
    tick++;
  }
  count += tick * OS_Tick_GetInterval();
  EvrRtxKernelGetSysTimerCount(count);
  return count;
}

/// Get the RTOS kernel system timer frequency.
/// \note API identical to osKernelGetSysTimerFreq
static uint32_t svcRtxKernelGetSysTimerFreq(void) {
  uint32_t freq = OS_Tick_GetClock();
  EvrRtxKernelGetSysTimerFreq(freq);
  return freq;
}

//  Service Calls definitions
// lint ++flb "Library Begin" [MISRA Note 11]
SVC0_0(KernelInitialize, osStatus_t)
SVC0_3(KernelGetInfo, osStatus_t, osVersion_t *, char *, uint32_t)
SVC0_0(KernelStart, osStatus_t)
SVC0_0(KernelLock, int32_t)
SVC0_0(KernelUnlock, int32_t)
SVC0_1(KernelRestoreLock, int32_t, int32_t)
SVC0_0(KernelSuspend, uint32_t)
SVC0_1N(KernelResume, void, uint32_t)
SVC0_0(KernelGetState, osKernelState_t)
SVC0_0(KernelGetTickCount, uint32_t)
SVC0_0(KernelGetTickFreq, uint32_t)
SVC0_0(KernelGetSysTimerCount, uint32_t)
SVC0_0(KernelGetSysTimerFreq, uint32_t)
// lint --flb "Library End"

//  ==== Library functions ====

/// RTOS Kernel Pre-Initialization Hook
// lint -esym(759,osRtxKernelPreInit) "Prototype in header"
// lint -esym(765,osRtxKernelPreInit) "Global scope (can be overridden)"
// lint -esym(522,osRtxKernelPreInit) "Can be overridden (do not lack
// side-effects)"
__WEAK void osRtxKernelPreInit(void) {}

//  ==== Public API ====

/// Initialize the RTOS Kernel.
osStatus_t osKernelInitialize(void) {
  osStatus_t status;

  osRtxKernelPreInit();
  EvrRtxKernelInitialize();
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
    status = osErrorISR;
  } else {
    status = __svcKernelInitialize();
  }
  return status;
}

///  Get RTOS Kernel Information.
osStatus_t osKernelGetInfo(osVersion_t *version, char *id_buf,
                           uint32_t id_size) {
  osStatus_t status;

  EvrRtxKernelGetInfo(version, id_buf, id_size);
  if (IsIrqMode() || IsIrqMasked() || IsPrivileged()) {
    status = svcRtxKernelGetInfo(version, id_buf, id_size);
  } else {
    status = __svcKernelGetInfo(version, id_buf, id_size);
  }
  return status;
}

/// Get the current RTOS Kernel state.
osKernelState_t osKernelGetState(void) {
  osKernelState_t state;

  if (IsIrqMode() || IsIrqMasked() || IsPrivileged()) {
    state = svcRtxKernelGetState();
  } else {
    state = __svcKernelGetState();
  }
  return state;
}

/// Start the RTOS Kernel scheduler.
osStatus_t osKernelStart(void) {
  osStatus_t status;

  EvrRtxKernelStart();
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
    status = osErrorISR;
  } else {
    status = __svcKernelStart();
  }
  return status;
}

/// Lock the RTOS Kernel scheduler.
int32_t osKernelLock(void) {
  int32_t lock;

  EvrRtxKernelLock();
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
    lock = (int32_t)osErrorISR;
  } else {
    lock = __svcKernelLock();
  }
  return lock;
}

/// Unlock the RTOS Kernel scheduler.
int32_t osKernelUnlock(void) {
  int32_t lock;

  EvrRtxKernelUnlock();
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
    lock = (int32_t)osErrorISR;
  } else {
    lock = __svcKernelUnlock();
  }
  return lock;
}

/// Restore the RTOS Kernel scheduler lock state.
int32_t osKernelRestoreLock(int32_t lock) {
  int32_t lock_new;

  EvrRtxKernelRestoreLock(lock);
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
    lock_new = (int32_t)osErrorISR;
  } else {
    lock_new = __svcKernelRestoreLock(lock);
  }
  return lock_new;
}

/// Suspend the RTOS Kernel scheduler.
uint32_t osKernelSuspend(void) {
  uint32_t ticks;

  EvrRtxKernelSuspend();
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
    ticks = 0U;
  } else {
    ticks = __svcKernelSuspend();
  }
  return ticks;
}

/// Resume the RTOS Kernel scheduler.
void osKernelResume(uint32_t sleep_ticks) {

  EvrRtxKernelResume(sleep_ticks);
  if (IsIrqMode() || IsIrqMasked()) {
    EvrRtxKernelError((int32_t)osErrorISR);
  } else {
    __svcKernelResume(sleep_ticks);
  }
}

/// Get the RTOS kernel tick count.
uint32_t osKernelGetTickCount(void) {
  uint32_t count;

  if (IsIrqMode() || IsIrqMasked()) {
    count = svcRtxKernelGetTickCount();
  } else {
    count = __svcKernelGetTickCount();
  }
  return count;
}

/// Get the RTOS kernel tick frequency.
uint32_t osKernelGetTickFreq(void) {
  uint32_t freq;

  if (IsIrqMode() || IsIrqMasked()) {
    freq = svcRtxKernelGetTickFreq();
  } else {
    freq = __svcKernelGetTickFreq();
  }
  return freq;
}

/// Get the RTOS kernel system timer count.
uint32_t osKernelGetSysTimerCount(void) {
  uint32_t count;

  if (IsIrqMode() || IsIrqMasked()) {
    count = svcRtxKernelGetSysTimerCount();
  } else {
    count = __svcKernelGetSysTimerCount();
  }
  return count;
}

/// Get the RTOS kernel system timer frequency.
uint32_t osKernelGetSysTimerFreq(void) {
  uint32_t freq;

  if (IsIrqMode() || IsIrqMasked()) {
    freq = svcRtxKernelGetSysTimerFreq();
  } else {
    freq = __svcKernelGetSysTimerFreq();
  }
  return freq;
}