nuttx

組員

• 翁振育
• 黃亮穎
• 蘇偉嘉
• 李英碩

Nuttx 參考應用

• PX4 autopilot<http://pixhawk.org/dev/nuttx/start>_

NuttX 架構

＊ 可混用task跟thread。 ＊ 支援FPU。 ＊ 可混用FIFO跟RR。

與平台相關

Run FreeRTOS on STM32F4-Discovery

Task state

.. code-block:: c

enum tstate_e { TSTATE_TASK_INVALID = 0, /* INVALID - The TCB is uninitialized / TSTATE_TASK_PENDING, / READY_TO_RUN - Pending preemption unlock / TSTATE_TASK_READYTORUN, / READY-TO-RUN - But not running / TSTATE_TASK_RUNNING, / READY_TO_RUN - And running / TSTATE_TASK_INACTIVE, / BLOCKED - Initialized but not yet activated / TSTATE_WAIT_SEM, / BLOCKED - Waiting for a semaphore / #ifndef CONFIG_DISABLE_SIGNALS TSTATE_WAIT_SIG, / BLOCKED - Waiting for a signal / #endif #ifndef CONFIG_DISABLE_MQUEUE TSTATE_WAIT_MQNOTEMPTY, / BLOCKED - Waiting for a MQ to become not empty. / TSTATE_WAIT_MQNOTFULL, / BLOCKED - Waiting for a MQ to become not full. / #endif #ifdef CONFIG_PAGING TSTATE_WAIT_PAGEFILL, / BLOCKED - Waiting for page fill / #endif NUM_TASK_STATES / Must be last */ };

Task list

.. code-block:: c

typedef struct tasklist_s tasklist_t;

extern volatile dq_queue_t g_readytorun; extern volatile dq_queue_t g_pendingtasks; extern volatile dq_queue_t g_waitingforsemaphore; #ifndef CONFIG_DISABLE_SIGNALS extern volatile dq_queue_t g_waitingforsignal; #endif #ifndef CONFIG_DISABLE_MQUEUE extern volatile dq_queue_t g_waitingformqnotempty; #endif #ifndef CONFIG_DISABLE_MQUEUE extern volatile dq_queue_t g_waitingformqnotfull; #endif #ifdef CONFIG_PAGING extern volatile dq_queue_t g_waitingforfill; #endif extern volatile dq_queue_t g_inactivetasks; extern volatile sq_queue_t g_delayed_kufree; #if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP) extern volatile sq_queue_t g_delayed_kfree; #endif extern volatile pid_t g_lastpid; extern pidhash_t g_pidhash[CONFIG_MAX_TASKS]; extern const tasklist_t g_tasklisttable[NUM_TASK_STATES];

TCB

.. code-block:: c

struct tcb_s { /* Fields used to support list management *************************************/ FAR struct tcb_s flink; / Doubly linked list / FAR struct tcb_s blink;

/* Task Management Fields *****************************************************/

pid_t pid; /* This is the ID of the thread */

start_t start; /* Thread start function / entry_t entry; / Entry Point into the thread / uint8_t sched_priority; / Current priority of the thread */

uint8_t task_state; /* Current state of the thread / uint16_t flags; / Misc. general status flags / int16_t lockcount; / 0=preemptable (not-locked) */

#if CONFIG_RR_INTERVAL > 0 int timeslice; /* RR timeslice interval remaining */ #endif

/* Stack-Related Fields *******************************************************/

#ifndef CONFIG_CUSTOM_STACK size_t adj_stack_size; /* Stack size after adjustment / / for hardware, processor, etc. / / (for debug purposes only) / FAR void stack_alloc_ptr; /* Pointer to allocated stack / / Need to deallocate stack / FAR void adj_stack_ptr; /* Adjusted stack_alloc_ptr for HW / / The initial stack pointer value */ #endif

/* POSIX Semaphore Control Fields *********************************************/

sem_t waitsem; / Semaphore ID waiting on */

/* POSIX Signal Control Fields ************************************************/

#ifndef CONFIG_DISABLE_SIGNALS sigset_t sigprocmask; /* Signals that are blocked / sigset_t sigwaitmask; / Waiting for pending signals / sq_queue_t sigactionq; / List of actions for signals / sq_queue_t sigpendactionq; / List of pending signal actions / sq_queue_t sigpostedq; / List of posted signals / siginfo_t sigunbinfo; / Signal info when task unblocked */ #endif

/* POSIX Named Message Queue Fields *******************************************/

#ifndef CONFIG_DISABLE_MQUEUE FAR msgq_t msgwaitq; / Waiting for this message queue */ #endif

/* The form and content of these fields are processor-specific. */

struct xcptcontext xcp; /* Interrupt register save area */

#if CONFIG_TASK_NAME_SIZE > 0 char name[CONFIG_TASK_NAME_SIZE]; /* Task name */ #endif };

Communication

Scheduling

Interrupt handler

測試環境架設

硬體驅動原理

• UART<embedded/USART>_
• FPU (Floating Point Unit)

效能表現

參考資料

• https://github.com/deadbeefcafe/nuttx-stm32f4disc-bb
• http://bibliodigital.itcr.ac.cr/xmlui/bitstream/handle/2238/3051/FinalReport.pdf