rt-thread/src/kservice.c

/*
 * Copyright (c) 2006-2024, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-03-16     Bernard      the first version
 * 2006-05-25     Bernard      rewrite vsprintf
 * 2006-08-10     Bernard      add rt_show_version
 * 2010-03-17     Bernard      remove rt_strlcpy function
 *                             fix gcc compiling issue.
 * 2010-04-15     Bernard      remove weak definition on ICCM16C compiler
 * 2012-07-18     Arda         add the alignment display for signed integer
 * 2012-11-23     Bernard      fix IAR compiler error.
 * 2012-12-22     Bernard      fix rt_kprintf issue, which found by Grissiom.
 * 2013-06-24     Bernard      remove rt_kprintf if RT_USING_CONSOLE is not defined.
 * 2013-09-24     aozima       make sure the device is in STREAM mode when used by rt_kprintf.
 * 2015-07-06     Bernard      Add rt_assert_handler routine.
 * 2021-02-28     Meco Man     add RT_KSERVICE_USING_STDLIB
 * 2021-12-20     Meco Man     implement rt_strcpy()
 * 2022-01-07     Gabriel      add __on_rt_assert_hook
 * 2022-06-04     Meco Man     remove strnlen
 * 2022-08-24     Yunjie       make rt_memset word-independent to adapt to ti c28x (16bit word)
 * 2022-08-30     Yunjie       make rt_vsnprintf adapt to ti c28x (16bit int)
 * 2023-02-02     Bernard      add Smart ID for logo version show
 * 2023-10-16     Shell        Add hook point for rt_malloc services
 * 2023-12-10     xqyjlj       perf rt_hw_interrupt_disable/enable, fix memheap lock
 * 2024-03-10     Meco Man     move std libc related functions to rtklibc
 */

#include <rtthread.h>
#include <rthw.h>

#define DBG_TAG           "kernel.service"
#ifdef RT_DEBUG_DEVICE
#define DBG_LVL           DBG_LOG
#else
#define DBG_LVL           DBG_WARNING
#endif /* defined (RT_DEBUG_DEVICE) */
#include <rtdbg.h>

#ifdef RT_USING_MODULE
#include <dlmodule.h>
#endif /* RT_USING_MODULE */

#ifdef RT_USING_SMART
#include <lwp.h>
#include <lwp_user_mm.h>
#endif

/**
 * @addtogroup KernelService
 * @{
 */

#if defined(RT_USING_DEVICE) && defined(RT_USING_CONSOLE)
static rt_device_t _console_device = RT_NULL;
#endif

rt_weak void rt_hw_us_delay(rt_uint32_t us)
{
    (void) us;
    LOG_W("rt_hw_us_delay() doesn't support for this board."
        "Please consider implementing rt_hw_us_delay() in another file.");
}

rt_weak void rt_hw_cpu_reset(void)
{
    LOG_W("rt_hw_cpu_reset() doesn't support for this board."
        "Please consider implementing rt_hw_cpu_reset() in another file.");
    return;
}

rt_weak void rt_hw_cpu_shutdown(void)
{
    rt_base_t level;
    LOG_I("CPU shutdown...");
    LOG_W("Using default rt_hw_cpu_shutdown()."
        "Please consider implementing rt_hw_cpu_reset() in another file.");
    level = rt_hw_interrupt_disable();
    while (level)
    {
        RT_ASSERT(RT_NULL);
    }
    return;
}

rt_weak rt_err_t rt_hw_backtrace_frame_get(rt_thread_t thread, struct rt_hw_backtrace_frame *frame)
{
    RT_UNUSED(thread);
    RT_UNUSED(frame);

    LOG_W("%s is not implemented", __func__);
    return -RT_ENOSYS;
}

rt_weak rt_err_t rt_hw_backtrace_frame_unwind(rt_thread_t thread, struct rt_hw_backtrace_frame *frame)
{
    RT_UNUSED(thread);
    RT_UNUSED(frame);

    LOG_W("%s is not implemented", __func__);
    return -RT_ENOSYS;
}

rt_weak const char *rt_hw_cpu_arch(void)
{
    return "unknown";
}

/**
 * @brief This function will show the version of rt-thread rtos
 */
void rt_show_version(void)
{
    rt_kprintf("\n \\ | /\n");
#if defined(RT_USING_SMART)
    rt_kprintf("- RT -     Thread Smart Operating System\n");
#elif defined(RT_USING_NANO)
    rt_kprintf("- RT -     Thread Nano Operating System\n");
#else
    rt_kprintf("- RT -     Thread Operating System\n");
#endif
    rt_kprintf(" / | \\     %d.%d.%d build %s %s\n",
               (rt_int32_t)RT_VERSION_MAJOR, (rt_int32_t)RT_VERSION_MINOR, (rt_int32_t)RT_VERSION_PATCH, __DATE__, __TIME__);
    rt_kprintf(" 2006 - 2024 Copyright by RT-Thread team\n");
}
RTM_EXPORT(rt_show_version);

#ifdef RT_USING_CONSOLE
#ifdef RT_USING_DEVICE
/**
 * @brief  This function returns the device using in console.
 *
 * @return Returns the console device pointer or RT_NULL.
 */
rt_device_t rt_console_get_device(void)
{
    return _console_device;
}
RTM_EXPORT(rt_console_get_device);

/**
 * @brief  This function will set a device as console device.
 * After set a device to console, all output of rt_kprintf will be
 * redirected to this new device.
 *
 * @param  name is the name of new console device.
 *
 * @return the old console device handler on successful, or RT_NULL on failure.
 */
rt_device_t rt_console_set_device(const char *name)
{
    rt_device_t new_device, old_device;

    /* save old device */
    old_device = _console_device;

    /* find new console device */
    new_device = rt_device_find(name);

    /* check whether it's a same device */
    if (new_device == old_device) return RT_NULL;

    if (new_device != RT_NULL)
    {
        if (_console_device != RT_NULL)
        {
            /* close old console device */
            rt_device_close(_console_device);
        }

        /* set new console device */
        rt_device_open(new_device, RT_DEVICE_OFLAG_RDWR | RT_DEVICE_FLAG_STREAM);
        _console_device = new_device;
    }

    return old_device;
}
RTM_EXPORT(rt_console_set_device);
#endif /* RT_USING_DEVICE */

rt_weak void rt_hw_console_output(const char *str)
{
    /* empty console output */
    RT_UNUSED(str);
}
RTM_EXPORT(rt_hw_console_output);

#ifdef RT_USING_THREADSAFE_PRINTF

/* system console lock */
static struct rt_spinlock _syscon_lock = RT_SPINLOCK_INIT;
/* lock of kprintf buffer */
static struct rt_spinlock _prbuf_lock = RT_SPINLOCK_INIT;
/* current user of system console */
static rt_thread_t _pr_curr_user;

#ifdef RT_USING_DEBUG
static rt_base_t _pr_critical_level;
#endif /* RT_USING_DEBUG */

/* nested level of current user */
static volatile int _pr_curr_user_nested;

rt_thread_t rt_console_current_user(void)
{
    return _pr_curr_user;
}

static void _console_take(void)
{
    rt_ubase_t level = rt_spin_lock_irqsave(&_syscon_lock);
    rt_thread_t self_thread = rt_thread_self();
    rt_base_t critical_level;
    RT_UNUSED(critical_level);

    while (_pr_curr_user != self_thread)
    {
        if (_pr_curr_user == RT_NULL)
        {
            /* no preemption is allowed to avoid dead lock */
            critical_level = rt_enter_critical();
#ifdef RT_USING_DEBUG
            _pr_critical_level = _syscon_lock.critical_level;
            _syscon_lock.critical_level = critical_level;
#endif
            _pr_curr_user = self_thread;
            break;
        }
        else
        {
            rt_spin_unlock_irqrestore(&_syscon_lock, level);
            rt_thread_yield();
            level = rt_spin_lock_irqsave(&_syscon_lock);
        }
    }

    _pr_curr_user_nested++;

    rt_spin_unlock_irqrestore(&_syscon_lock, level);
}

static void _console_release(void)
{
    rt_ubase_t level = rt_spin_lock_irqsave(&_syscon_lock);
    rt_thread_t self_thread = rt_thread_self();
    RT_UNUSED(self_thread);

    RT_ASSERT(_pr_curr_user == self_thread);

    _pr_curr_user_nested--;
    if (!_pr_curr_user_nested)
    {
        _pr_curr_user = RT_NULL;

#ifdef RT_USING_DEBUG
        rt_exit_critical_safe(_syscon_lock.critical_level);
        _syscon_lock.critical_level = _pr_critical_level;
#else
        rt_exit_critical();
#endif
    }
    rt_spin_unlock_irqrestore(&_syscon_lock, level);
}

#define CONSOLE_TAKE          _console_take()
#define CONSOLE_RELEASE       _console_release()
#define PRINTF_BUFFER_TAKE    rt_ubase_t level = rt_spin_lock_irqsave(&_prbuf_lock)
#define PRINTF_BUFFER_RELEASE rt_spin_unlock_irqrestore(&_prbuf_lock, level)
#else

#define CONSOLE_TAKE
#define CONSOLE_RELEASE
#define PRINTF_BUFFER_TAKE
#define PRINTF_BUFFER_RELEASE
#endif /* RT_USING_THREADSAFE_PRINTF */

/**
 * @brief This function will put string to the console.
 *
 * @param str is the string output to the console.
 */
static void _kputs(const char *str, long len)
{
    RT_UNUSED(len);

    CONSOLE_TAKE;

#ifdef RT_USING_DEVICE
    if (_console_device == RT_NULL)
    {
        rt_hw_console_output(str);
    }
    else
    {
        rt_device_write(_console_device, 0, str, len);
    }
#else
    rt_hw_console_output(str);
#endif /* RT_USING_DEVICE */

    CONSOLE_RELEASE;
}

/**
 * @brief This function will put string to the console.
 *
 * @param str is the string output to the console.
 */
void rt_kputs(const char *str)
{
    if (!str)
    {
        return;
    }

    _kputs(str, rt_strlen(str));
}

/**
 * @brief This function will print a formatted string on system console.
 *
 * @param fmt is the format parameters.
 *
 * @return The number of characters actually written to buffer.
 */
rt_weak int rt_kprintf(const char *fmt, ...)
{
    va_list args;
    rt_size_t length = 0;
    static char rt_log_buf[RT_CONSOLEBUF_SIZE];

    va_start(args, fmt);
    PRINTF_BUFFER_TAKE;

    /* the return value of vsnprintf is the number of bytes that would be
     * written to buffer had if the size of the buffer been sufficiently
     * large excluding the terminating null byte. If the output string
     * would be larger than the rt_log_buf, we have to adjust the output
     * length. */
    length = rt_vsnprintf(rt_log_buf, sizeof(rt_log_buf) - 1, fmt, args);
    if (length > RT_CONSOLEBUF_SIZE - 1)
    {
        length = RT_CONSOLEBUF_SIZE - 1;
    }

    _kputs(rt_log_buf, length);

    PRINTF_BUFFER_RELEASE;
    va_end(args);

    return length;
}
RTM_EXPORT(rt_kprintf);
#endif /* RT_USING_CONSOLE */

#ifdef __GNUC__
rt_weak rt_err_t rt_backtrace(void)
{
    struct rt_hw_backtrace_frame frame = {
        .fp = (rt_base_t)__builtin_frame_address(0U),
        .pc = ({__label__ pc; pc: (rt_base_t)&&pc;})
    };
    rt_hw_backtrace_frame_unwind(rt_thread_self(), &frame);
    return rt_backtrace_frame(&frame);
}

#else /* otherwise not implemented */
rt_weak rt_err_t rt_backtrace(void)
{
   /* LOG_W cannot work under this environment */
    rt_kprintf("%s is not implemented\n", __func__);
    return -RT_ENOSYS;
}
#endif

rt_err_t rt_backtrace_frame(struct rt_hw_backtrace_frame *frame)
{
    long nesting = 0;

    rt_kprintf("please use: addr2line -e rtthread.elf -a -f");

    while (nesting < RT_BACKTRACE_LEVEL_MAX_NR)
    {
        rt_kprintf(" 0x%lx", (rt_ubase_t)frame->pc);
        if (rt_hw_backtrace_frame_unwind(rt_thread_self(), frame))
        {
            break;
        }
        nesting++;
    }
    rt_kprintf("\n");
    return RT_EOK;
}

rt_err_t rt_backtrace_thread(rt_thread_t thread)
{
    rt_err_t rc;
    struct rt_hw_backtrace_frame frame;
    if (thread)
    {
        rc = rt_hw_backtrace_frame_get(thread, &frame);
        if (rc == RT_EOK)
        {
            rc = rt_backtrace_frame(&frame);
        }
    }
    else
    {
        rc = -RT_EINVAL;
    }
    return rc;
}

#if defined(RT_USING_LIBC) && defined(RT_USING_FINSH)
#include <stdlib.h> /* for string service */

static void cmd_backtrace(int argc, char** argv)
{
    rt_ubase_t pid;
    char *end_ptr;

    if (argc != 2)
    {
        if (argc == 1)
        {
            rt_kprintf("[INFO] No thread specified\n"
                "[HELP] You can use commands like: backtrace %p\n"
                "Printing backtrace of calling stack...\n",
                rt_thread_self());
            rt_backtrace();
            return ;
        }
        else
        {
            rt_kprintf("please use: backtrace [thread_address]\n");
            return;
        }
    }

    pid = strtoul(argv[1], &end_ptr, 0);
    if (end_ptr == argv[1])
    {
        rt_kprintf("Invalid input: %s\n", argv[1]);
        return ;
    }

    if (pid && rt_object_get_type((void *)pid) == RT_Object_Class_Thread)
    {
        rt_thread_t target = (rt_thread_t)pid;
        rt_kprintf("backtrace %s(0x%lx), from %s\n", target->parent.name, pid, argv[1]);
        rt_backtrace_thread(target);
    }
    else
        rt_kprintf("Invalid pid: %ld\n", pid);
}
MSH_CMD_EXPORT_ALIAS(cmd_backtrace, backtrace, print backtrace of a thread);

#endif /* RT_USING_LIBC */

#if defined(RT_USING_HEAP) && !defined(RT_USING_USERHEAP)
#ifdef RT_USING_HOOK
static void (*rt_malloc_hook)(void **ptr, rt_size_t size);
static void (*rt_realloc_entry_hook)(void **ptr, rt_size_t size);
static void (*rt_realloc_exit_hook)(void **ptr, rt_size_t size);
static void (*rt_free_hook)(void **ptr);

/**
 * @addtogroup Hook
 * @{
 */

/**
 * @brief This function will set a hook function, which will be invoked when a memory
 *        block is allocated from heap memory.
 *
 * @param hook the hook function.
 */
void rt_malloc_sethook(void (*hook)(void **ptr, rt_size_t size))
{
    rt_malloc_hook = hook;
}

/**
 * @brief This function will set a hook function, which will be invoked when a memory
 *        block is allocated from heap memory.
 *
 * @param hook the hook function.
 */
void rt_realloc_set_entry_hook(void (*hook)(void **ptr, rt_size_t size))
{
    rt_realloc_entry_hook = hook;
}

/**
 * @brief This function will set a hook function, which will be invoked when a memory
 *        block is allocated from heap memory.
 *
 * @param hook the hook function.
 */
void rt_realloc_set_exit_hook(void (*hook)(void **ptr, rt_size_t size))
{
    rt_realloc_exit_hook = hook;
}

/**
 * @brief This function will set a hook function, which will be invoked when a memory
 *        block is released to heap memory.
 *
 * @param hook the hook function
 */
void rt_free_sethook(void (*hook)(void **ptr))
{
    rt_free_hook = hook;
}

/**@}*/

#endif /* RT_USING_HOOK */

#if defined(RT_USING_HEAP_ISR)
static struct rt_spinlock _heap_spinlock;
#elif defined(RT_USING_MUTEX)
static struct rt_mutex _lock;
#endif

rt_inline void _heap_lock_init(void)
{
#if defined(RT_USING_HEAP_ISR)
    rt_spin_lock_init(&_heap_spinlock);
#elif defined(RT_USING_MUTEX)
    rt_mutex_init(&_lock, "heap", RT_IPC_FLAG_PRIO);
#endif
}

rt_inline rt_base_t _heap_lock(void)
{
#if defined(RT_USING_HEAP_ISR)
    return rt_spin_lock_irqsave(&_heap_spinlock);
#elif defined(RT_USING_MUTEX)
    if (rt_thread_self())
        return rt_mutex_take(&_lock, RT_WAITING_FOREVER);
    else
        return RT_EOK;
#else
    rt_enter_critical();
    return RT_EOK;
#endif
}

rt_inline void _heap_unlock(rt_base_t level)
{
#if defined(RT_USING_HEAP_ISR)
    rt_spin_unlock_irqrestore(&_heap_spinlock, level);
#elif defined(RT_USING_MUTEX)
    RT_ASSERT(level == RT_EOK);
    if (rt_thread_self())
        rt_mutex_release(&_lock);
#else
    rt_exit_critical();
#endif
}

#ifdef RT_USING_UTESTCASES
/* export to utest to observe the inner statements */
#ifdef _MSC_VER
#define rt_heap_lock() _heap_lock()
#define rt_heap_unlock() _heap_unlock()
#else
rt_base_t rt_heap_lock(void) __attribute__((alias("_heap_lock")));
void rt_heap_unlock(rt_base_t level) __attribute__((alias("_heap_unlock")));
#endif /* _MSC_VER */
#endif

#if defined(RT_USING_SMALL_MEM_AS_HEAP)
static rt_smem_t system_heap;
rt_inline void _smem_info(rt_size_t *total,
    rt_size_t *used, rt_size_t *max_used)
{
    if (total)
        *total = system_heap->total;
    if (used)
        *used = system_heap->used;
    if (max_used)
        *max_used = system_heap->max;
}
#define _MEM_INIT(_name, _start, _size) \
    system_heap = rt_smem_init(_name, _start, _size)
#define _MEM_MALLOC(_size)  \
    rt_smem_alloc(system_heap, _size)
#define _MEM_REALLOC(_ptr, _newsize)\
    rt_smem_realloc(system_heap, _ptr, _newsize)
#define _MEM_FREE(_ptr) \
    rt_smem_free(_ptr)
#define _MEM_INFO(_total, _used, _max)  \
    _smem_info(_total, _used, _max)
#elif defined(RT_USING_MEMHEAP_AS_HEAP)
static struct rt_memheap system_heap;
void *_memheap_alloc(struct rt_memheap *heap, rt_size_t size);
void _memheap_free(void *rmem);
void *_memheap_realloc(struct rt_memheap *heap, void *rmem, rt_size_t newsize);
#define _MEM_INIT(_name, _start, _size) \
    do {\
        rt_memheap_init(&system_heap, _name, _start, _size); \
        system_heap.locked = RT_TRUE; \
    } while(0)
#define _MEM_MALLOC(_size)  \
    _memheap_alloc(&system_heap, _size)
#define _MEM_REALLOC(_ptr, _newsize)    \
    _memheap_realloc(&system_heap, _ptr, _newsize)
#define _MEM_FREE(_ptr)   \
    _memheap_free(_ptr)
#define _MEM_INFO(_total, _used, _max)   \
    rt_memheap_info(&system_heap, _total, _used, _max)
#elif defined(RT_USING_SLAB_AS_HEAP)
static rt_slab_t system_heap;
rt_inline void _slab_info(rt_size_t *total,
    rt_size_t *used, rt_size_t *max_used)
{
    if (total)
        *total = system_heap->total;
    if (used)
        *used = system_heap->used;
    if (max_used)
        *max_used = system_heap->max;
}
#define _MEM_INIT(_name, _start, _size) \
    system_heap = rt_slab_init(_name, _start, _size)
#define _MEM_MALLOC(_size)  \
    rt_slab_alloc(system_heap, _size)
#define _MEM_REALLOC(_ptr, _newsize)    \
    rt_slab_realloc(system_heap, _ptr, _newsize)
#define _MEM_FREE(_ptr) \
    rt_slab_free(system_heap, _ptr)
#define _MEM_INFO       _slab_info
#else
#define _MEM_INIT(...)
#define _MEM_MALLOC(...)     RT_NULL
#define _MEM_REALLOC(...)    RT_NULL
#define _MEM_FREE(...)
#define _MEM_INFO(...)
#endif

static void _rt_system_heap_init(void *begin_addr, void *end_addr)
{
    rt_ubase_t begin_align = RT_ALIGN((rt_ubase_t)begin_addr, RT_ALIGN_SIZE);
    rt_ubase_t end_align   = RT_ALIGN_DOWN((rt_ubase_t)end_addr, RT_ALIGN_SIZE);

    RT_ASSERT(end_align > begin_align);

    /* Initialize system memory heap */
    _MEM_INIT("heap", (void *)begin_align, end_align - begin_align);
    /* Initialize multi thread contention lock */
    _heap_lock_init();
}

/**
 * @brief This function will init system heap.
 *
 * @param begin_addr the beginning address of system page.
 *
 * @param end_addr the end address of system page.
 */
rt_weak void rt_system_heap_init(void *begin_addr, void *end_addr)
{
    _rt_system_heap_init(begin_addr, end_addr);
}

/**
 * @brief Allocate a block of memory with a minimum of 'size' bytes.
 *
 * @param size is the minimum size of the requested block in bytes.
 *
 * @return the pointer to allocated memory or NULL if no free memory was found.
 */
rt_weak void *rt_malloc(rt_size_t size)
{
    rt_base_t level;
    void *ptr;

    /* Enter critical zone */
    level = _heap_lock();
    /* allocate memory block from system heap */
    ptr = _MEM_MALLOC(size);
    /* Exit critical zone */
    _heap_unlock(level);
    /* call 'rt_malloc' hook */
    RT_OBJECT_HOOK_CALL(rt_malloc_hook, (&ptr, size));
    return ptr;
}
RTM_EXPORT(rt_malloc);

/**
 * @brief This function will change the size of previously allocated memory block.
 *
 * @param ptr is the pointer to memory allocated by rt_malloc.
 *
 * @param newsize is the required new size.
 *
 * @return the changed memory block address.
 */
rt_weak void *rt_realloc(void *ptr, rt_size_t newsize)
{
    rt_base_t level;
    void *nptr;

    /* Entry hook */
    RT_OBJECT_HOOK_CALL(rt_realloc_entry_hook, (&ptr, newsize));
    /* Enter critical zone */
    level = _heap_lock();
    /* Change the size of previously allocated memory block */
    nptr = _MEM_REALLOC(ptr, newsize);
    /* Exit critical zone */
    _heap_unlock(level);
    /* Exit hook */
    RT_OBJECT_HOOK_CALL(rt_realloc_exit_hook, (&nptr, newsize));
    return nptr;
}
RTM_EXPORT(rt_realloc);

/**
 * @brief  This function will contiguously allocate enough space for count objects
 *         that are size bytes of memory each and returns a pointer to the allocated
 *         memory.
 *
 * @note   The allocated memory is filled with bytes of value zero.
 *
 * @param  count is the number of objects to allocate.
 *
 * @param  size is the size of one object to allocate.
 *
 * @return pointer to allocated memory / NULL pointer if there is an error.
 */
rt_weak void *rt_calloc(rt_size_t count, rt_size_t size)
{
    void *p;

    /* allocate 'count' objects of size 'size' */
    p = rt_malloc(count * size);
    /* zero the memory */
    if (p)
    {
        rt_memset(p, 0, count * size);
    }
    return p;
}
RTM_EXPORT(rt_calloc);

/**
 * @brief This function will release the previously allocated memory block by
 *        rt_malloc. The released memory block is taken back to system heap.
 *
 * @param ptr the address of memory which will be released.
 */
rt_weak void rt_free(void *ptr)
{
    rt_base_t level;

    /* call 'rt_free' hook */
    RT_OBJECT_HOOK_CALL(rt_free_hook, (&ptr));
    /* NULL check */
    if (ptr == RT_NULL) return;
    /* Enter critical zone */
    level = _heap_lock();
    _MEM_FREE(ptr);
    /* Exit critical zone */
    _heap_unlock(level);
}
RTM_EXPORT(rt_free);

/**
* @brief This function will caculate the total memory, the used memory, and
*        the max used memory.
*
* @param total is a pointer to get the total size of the memory.
*
* @param used is a pointer to get the size of memory used.
*
* @param max_used is a pointer to get the maximum memory used.
*/
rt_weak void rt_memory_info(rt_size_t *total,
                            rt_size_t *used,
                            rt_size_t *max_used)
{
    rt_base_t level;

    /* Enter critical zone */
    level = _heap_lock();
    _MEM_INFO(total, used, max_used);
    /* Exit critical zone */
    _heap_unlock(level);
}
RTM_EXPORT(rt_memory_info);

#if defined(RT_USING_SLAB) && defined(RT_USING_SLAB_AS_HEAP)
void *rt_page_alloc(rt_size_t npages)
{
    rt_base_t level;
    void *ptr;

    /* Enter critical zone */
    level = _heap_lock();
    /* alloc page */
    ptr = rt_slab_page_alloc(system_heap, npages);
    /* Exit critical zone */
    _heap_unlock(level);
    return ptr;
}

void rt_page_free(void *addr, rt_size_t npages)
{
    rt_base_t level;

    /* Enter critical zone */
    level = _heap_lock();
    /* free page */
    rt_slab_page_free(system_heap, addr, npages);
    /* Exit critical zone */
    _heap_unlock(level);
}
#endif

/**
 * @brief  This function allocates a memory block, which address is aligned to the
 * specified alignment size.
 *
 * @param  size is the allocated memory block size.
 *
 * @param  align is the alignment size.
 *
 * @return The memory block address was returned successfully, otherwise it was
 *         returned empty RT_NULL.
 */
rt_weak void *rt_malloc_align(rt_size_t size, rt_size_t align)
{
    void *ptr = RT_NULL;
    void *align_ptr = RT_NULL;
    int uintptr_size = 0;
    rt_size_t align_size = 0;

    /* sizeof pointer */
    uintptr_size = sizeof(void*);
    uintptr_size -= 1;

    /* align the alignment size to uintptr size byte */
    align = ((align + uintptr_size) & ~uintptr_size);

    /* get total aligned size */
    align_size = ((size + uintptr_size) & ~uintptr_size) + align;
    /* allocate memory block from heap */
    ptr = rt_malloc(align_size);
    if (ptr != RT_NULL)
    {
        /* the allocated memory block is aligned */
        if (((rt_ubase_t)ptr & (align - 1)) == 0)
        {
            align_ptr = (void *)((rt_ubase_t)ptr + align);
        }
        else
        {
            align_ptr = (void *)(((rt_ubase_t)ptr + (align - 1)) & ~(align - 1));
        }

        /* set the pointer before alignment pointer to the real pointer */
        *((rt_ubase_t *)((rt_ubase_t)align_ptr - sizeof(void *))) = (rt_ubase_t)ptr;

        ptr = align_ptr;
    }

    return ptr;
}
RTM_EXPORT(rt_malloc_align);

/**
 * @brief This function release the memory block, which is allocated by
 * rt_malloc_align function and address is aligned.
 *
 * @param ptr is the memory block pointer.
 */
rt_weak void rt_free_align(void *ptr)
{
    void *real_ptr = RT_NULL;

    /* NULL check */
    if (ptr == RT_NULL) return;
    real_ptr = (void *) * (rt_ubase_t *)((rt_ubase_t)ptr - sizeof(void *));
    rt_free(real_ptr);
}
RTM_EXPORT(rt_free_align);
#endif /* RT_USING_HEAP */

#ifndef RT_USING_CPU_FFS
#ifdef RT_USING_TINY_FFS
const rt_uint8_t __lowest_bit_bitmap[] =
{
    /*  0 - 7  */  0,  1,  2, 27,  3, 24, 28, 32,
    /*  8 - 15 */  4, 17, 25, 31, 29, 12, 32, 14,
    /* 16 - 23 */  5,  8, 18, 32, 26, 23, 32, 16,
    /* 24 - 31 */ 30, 11, 13,  7, 32, 22, 15, 10,
    /* 32 - 36 */  6, 21,  9, 20, 19
};

/**
 * @brief This function finds the first bit set (beginning with the least significant bit)
 * in value and return the index of that bit.
 *
 * Bits are numbered starting at 1 (the least significant bit).  A return value of
 * zero from any of these functions means that the argument was zero.
 *
 * @param value is the value to find the first bit set in.
 *
 * @return return the index of the first bit set. If value is 0, then this function
 * shall return 0.
 */
int __rt_ffs(int value)
{
    return __lowest_bit_bitmap[(rt_uint32_t)(value & (value - 1) ^ value) % 37];
}
#else
const rt_uint8_t __lowest_bit_bitmap[] =
{
    /* 00 */ 0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 10 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 20 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 30 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 40 */ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 50 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 60 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 70 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 80 */ 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* 90 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* A0 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* B0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* C0 */ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* D0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* E0 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
    /* F0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
};

/**
 * @brief This function finds the first bit set (beginning with the least significant bit)
 * in value and return the index of that bit.
 *
 * Bits are numbered starting at 1 (the least significant bit).  A return value of
 * zero from any of these functions means that the argument was zero.
 *
 * @param value is the value to find the first bit set in.
 *
 * @return Return the index of the first bit set. If value is 0, then this function
 *         shall return 0.
 */
int __rt_ffs(int value)
{
    if (value == 0)
    {
        return 0;
    }

    if (value & 0xff)
    {
        return __lowest_bit_bitmap[value & 0xff] + 1;
    }

    if (value & 0xff00)
    {
        return __lowest_bit_bitmap[(value & 0xff00) >> 8] + 9;
    }

    if (value & 0xff0000)
    {
        return __lowest_bit_bitmap[(value & 0xff0000) >> 16] + 17;
    }

    return __lowest_bit_bitmap[(value & 0xff000000) >> 24] + 25;
}
#endif /* RT_USING_TINY_FFS */
#endif /* RT_USING_CPU_FFS */

#ifdef RT_DEBUGING_ASSERT
/* RT_ASSERT(EX)'s hook */

void (*rt_assert_hook)(const char *ex, const char *func, rt_size_t line);

/**
 * This function will set a hook function to RT_ASSERT(EX). It will run when the expression is false.
 *
 * @param hook is the hook function.
 */
void rt_assert_set_hook(void (*hook)(const char *ex, const char *func, rt_size_t line))
{
    rt_assert_hook = hook;
}

/**
 * The RT_ASSERT function.
 *
 * @param ex_string is the assertion condition string.
 *
 * @param func is the function name when assertion.
 *
 * @param line is the file line number when assertion.
 */
void rt_assert_handler(const char *ex_string, const char *func, rt_size_t line)
{
    volatile char dummy = 0;

    if (rt_assert_hook == RT_NULL)
    {
#ifdef RT_USING_MODULE
        if (dlmodule_self())
        {
            /* close assertion module */
            dlmodule_exit(-1);
        }
        else
#endif /*RT_USING_MODULE*/
        {
            rt_kprintf("(%s) assertion failed at function:%s, line number:%d \n", ex_string, func, line);
            rt_backtrace();
            while (dummy == 0);
        }
    }
    else
    {
        rt_assert_hook(ex_string, func, line);
    }
}
RTM_EXPORT(rt_assert_handler);
#endif /* RT_DEBUGING_ASSERT */

/**@}*/