threadx学习重点笔记专业资料.doc

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1、threadx学习笔记（一）tx_ill.s文献用来解决初始化过程中汇编语言，它是面向解决器和开发工具。Void_tx_initialize_low_level1、CPSCR|= FIQ_ MODE,SET SP_fiq;2、CPSCR|=IRQ_MODE,SET SP_irp;3、CPSCR|=SVC_MODE,SET SP_svc;4、设立中断向量表IRQ_TABLE;5、设立内部TIMER线程堆栈起始地址，堆栈大小和优先级：tx_timer_stack_start,_tx_timer_stack_size,_tx_timer_priorit;6、设立初始化后未使用内存地址初始值_tx_i

2、nitialize_unused_memory;Tx_tcs.s负责在中断发生时对上次运营现场进行保存，它保存中断上下文，为了不覆盖R14_irq离得中断返回地址，TCS返回是通过跳到_tx_irq_processing_return地址做到。Tx_TCR.S负责中断解决程序执行完后解决。Void _tx_thread_context_save1、把表达中断嵌套个数变量_tx_thread_system_state+;2、if _tx_thread_system_state1,PUSH R0-R3,CPSR,R14 in IRQ stack,B _tx_irq_processing_retur

3、n;3、else if _tx_thread_current_ptr=0判断与否有线程正在运营，if not ,B _tx_irq_processing_return;4、else,PUSH Context_irq in threads stack,SP_thread=new SP,B _tx_irq_processing_return;由于R13和R14在不同CPU模式下相应是不同物理寄存器，因此若要得到中断前线程堆栈指针，需要先返回到该线程运营模式，同步禁止中断，取值后再返回到终端模式。R14_irq保存是终端发生时PC值+8，R14_svc保存得失中断前线程自己返回地址。因此在中段上下文

4、中，（R14_irq-4）应当存在中断地址，而R14_svc存在R14位置。Void _tx_thread_context_restore1、_tx_thread_system_state-,if _tx_thread_system_state0,POP R0-R3,CPSR,R14 from IRQ stack,BX R14;2、else if _tx_thread_current_ptr=0?if =0 CPSR|=VC_MODE,CPSR|=TX_INT_ENABLE,跳到线程调度程序B _tx_thread_schedule;3、if!=0,则判断线程抢占与否禁止 if _tx_thr

5、ead_preempt_disable=0?if!=0,POP Context_irq from threads stack,BX R14;4、if=0,_tx_timer_time_slice=new value,_tx_thread_current_ptr=0,CPSR|=SVC_MODE,设立堆栈指针为系统指针SP=SP_svc，CPSR|=TX_INT_ENABLE;5、B _tx_thread_schedule;Tx_tsr.s用于从线程退回到系统态，负责保存线程最小语境并退回到Threadx调度循环状态。它保存上下文是祈求上下文。Void _tx_thread_system_ret

6、urn1、 PUSH Context_request:in threads stack,CPSR|=TX_INT_DISABLE;2、 _tx_thread_current_ptr-SP=SP,CPSR|=SVC_MODE;3、 设立堆栈指针为系统指针SP=SP_svc，_tx_thread_current_ptr=0,CPSR|=TX_INT_ENABLE;4、 B _tx_thread_schedule;由于顾客模式不能直接更改CPSR来关断，因此要通过SWI指令进入特权模式，并且特权模式和顾客模式SP相应不同物理寄存器，因此要在转入系统模式获得顾客模式下SP，最后再回到特权模式。TX_T

7、S.S负责调度和恢复就绪优先级最高线程最后语境。Void _tx_thread_schedule1、 while(_tx_thread_execute_ptr=0);2、 CPSR|=TX_INT_DISABLE,_tx_threadx_current_ptr=_tx_thread_execute_ptr;3、 _tx_thread_current_ptr-TX_run_count+,_tx_timer_time_slice=_tx_thread_current_ptr-tx_time_slice;4、 If线程堆栈中断类型=1，restore Context_irq,else restore

8、 Context_request;Tx_tic.s用于开中断和关中断。Unint _tx_thread_interrupt_control(unint new _posture)1、 R1=CPSR;2、 SWI；3、 CPSR|=RO=new posture;4、 R0=R1,R0为返回值；移植该函数时，针对不同解决器，应盖依照准热爱寄存器CPSR中断禁止将来设立开关中断向量，重要修改TX_PORT.H中TX_INT_ENABLE和TX_INT_DISABLE.R0用来传递参数和成果。Tx_tsb.s负责创立每个线程初始堆栈构造，这个初始构造在线程创立时会引起中断上下文返回到_tx_thre

9、ad_shell_entry函数开头。然后这个函数调用指定线程入口函数。其中断类型设立为1，表达中断上下文。Void _tx_thread_stack_build(TXTHREAD *thread_ptr,void (*function)(void)1、 保证堆栈起始地址八字节对齐；2、 中断地址存入线程调用入口地址PUSH function_ptr;3、 R0-R12,R14初始值都设立为0，PUSH初始值；4、 要存入堆栈CPSR值设立为顾客模式，开中断，标志位清零，R1=USER_MODE,PUSH R1;5、 Thread_ptr-sp=new SP;当解决一种低档中断时，tx_tpc

10、.s决定与否发生抢占，它是可选，大多数端口都用不到。TX_TIMIN.S负责解决定期中断。这两个函数只要将它们翻译成相应ARM汇编语言就可以了。threadx学习笔记（二）-1tx_kernel_enter();进入threadx核tx_kernel_enter()void tx_kernel_enter(void)所属文献调用者开关量demo.C启动代码无操作系统一方面从从量表直接进入该函数，在函数此前没有进行任何硬件及软件初始化！该函数重要包括_tx_initialize_low_level()，_tx_initialize_high_level()，tx_application_defi

11、ne(_tx_initialize_unused_memory)，_tx_thread_schedule()。VOID _tx_initialize_kernel_enter(VOID)/*拟定编译器与否已经初始化过 */if (_tx_thread_system_state != TX_INITIALIZE_ALMOST_DONE)/* 没有初始化话执行下面程序 */* 设立系统状态变量来表达现正在解决过程中 注意该变量在后边中断嵌套中会使用*/_tx_thread_system_state = TX_INITIALIZE_IN_PROGRESS;/* 进行某些基本硬件设立，启动程序等 */

12、_tx_initialize_low_level();/*进行某些高档初始化*/_tx_initialize_high_level();/*设立系统状态变量来表达现正在解决过程中 注意该变量在后边中断嵌套中会使用*/_tx_thread_system_state = TX_INITIALIZE_IN_PROGRESS;/* 调用初始化中提供应用程序 把第一种未使用变量地址传送给它 */tx_application_define(_tx_initialize_unused_memory);/*设立系统壮伟进入线程调度做准备*/_tx_thread_system_state = TX_INITIA

13、LIZE_IS_FINISHED;/* 进入线程循环开始执行线程 */_tx_thread_schedule();_tx_initialize_low_level()void tx_kernel_enter(void)所属文献调用者开关量tx_till.s启动代码无该函数实现对FIQ、IRQ和SVC模式下sp寄存器初始化，并对定期堆栈基地址、大小和定期优先级变量进行初始化。/* 进行某些基本硬件设立，启动程序等 */*该函数在文献tx_ill.s文献中*/_tx_initialize_low_level();/* VOID _tx_initialize_low_level(VOID);EXPO

14、RT _tx_initialize_low_level_tx_initialize_low_level；/* 保存系统堆栈指针. */；/* _tx_thread_system_stack_ptr = (VOID_PTR) A7 (SP)；*/;/*设立各个模式下sp（堆栈指针）*/；/* We must be in SVC mode at this point！*/;LDR a2，=|Image$ZI$Limit| ；Get end of non-initialized RAM areaLDR a3，pc，#FIQ_STACK_SIZE-.-8 ；获得FIO堆栈地址（这里没有弄明白，有待？）

15、MOV a1，#FIQ_MODE ；设立FIQ_MODEMSR CPSR_c，a1 ；进入FIQ模式ADD a2，a2，a3 ;计算FIQ堆栈开始BIC a2，a2，#3 ；将a2低两位清零保证堆栈开始为long对齐SUB a2，a2，#4 ；往回退一种字MOV sp，a2 ；建立FIQ 堆栈指针（即FIQ模式sp）MOV sl，#0 ；Clear sl（R10）MOV fp，#0 ；Clear fp(R11)LDR a3，pc，#SYS_STACK_SIZE-.-8 ;获得 IRQ (system stack size)MOV a1，#IRQ_MODE ；建立IRQ模式 CPSRMSR CP

16、SR_c，a1 ；进入IRQ模式ADD a2，a2，a3 ；计算IRQ stack开始BIC a2，a2，#3 ；将a2低两位清零保证堆栈开始为long对齐SUB a2，a2，#4 ；往回退一种字MOV sp，a2 ；建立 IRQ 堆栈指针MOV a1，#SVC_MODE ；建立SVC模式CPSRMSR CPSR_c，a1 ；进入 SVC模式LDR a4，pc，#SYS_STACK_PTR-.-8 ；获得stack 指针STR a2，a4，#0 ；保存系统堆栈;；/* Save the system stack pointer. */；_tx_thread_system_stack_ptr =

17、 (VOID_PTR) (sp);LDR a2，pc，#SYS_STACK_PTR-.-8 ；获得系统堆栈指针地址LDR a1，a2，#0 ；获得系统堆栈指针 ADD a1，a1，#4 ；增长一种long长度;；/* Pickup the first available memory address. */;；/* Allocate space for the timer threads stack. */；_tx_timer_stack_start = first_available_memory;；_tx_timer_stack_size = stack_size;；_tx_timer_p

18、riority = 0;LDR a2，pc，#TIMER_STACK-.-8 ；获得定期堆栈指针地址LDR a4，pc，#TIMER_STACK_SIZE-.-8 ；获得定期堆栈大小地址LDR a3，pc，#TIM_STACK_SIZE-.-8 ；获得实际定期堆栈大小STR a1，a2，#0 ;将定期堆栈基地址放在堆栈指针地址所相应内存中STR a3，a4，#0 ；存储定期器堆栈大小ADD a1，a1，a3 ；新空内存地址LDR a2，pc，#TIMER_PRIORITY-.-8 ；获得定期器优先级地址MOV a3，#0 ；获得定期器线程优先级STR a3，a2，#0 ；存储定期器线程优先级；

19、/*保存第一种变量内存地址. */；_tx_initialize_unused_memory = (VOID_PTR) System Stack + Timer Stack;LDR a3，pc，#UNUSED_MEMORY-.-8 ;获得没有使用内存指针地址STR a1，a3，#0 ；保存第一种空内存地址；/* 建立周期性定期中断. */STMDB LR/让lr入栈，保护lrBLTargetInit/TargetInit（）为C语言编写中断定期函数LDMIA lr/让lr出栈在这里加上ARM定期器已实现周期性中断；/* Done，return to caller. */;MOV pc，lr ；

20、Return to caller;_tx_irq_handler所属文献调用者开关量tx_till.s IRQ中断无该函数是在定期中断后调用，该函数调用了_tx_thread_context_save函数（包括在tx_tcs.s中），该函数又调用到_tx_irq_processing_return函数处（包括在tx_till.s）EXPORT _tx_irq_handlerEXPORT _tx_irq_processing_return _tx_irq_handler;；/* 调用函数保存线程上下文环境. */B _tx_thread_context_save_tx_irq_processin

21、g_return;；/* At this point execution is still in the IRQ mode. The CPSR，point of；interrupt，and all C scratch registers are available for use. In ；addition，IRQ interrupts may be re-enabled - with certain restrictions -；if nested IRQ interrupts are desired. Interrupts may be re-enabled over；small code

22、 sequences where lr is saved before enabling interrupts and ；restored after interrupts are again disabled. */;；/* For debug purpose，execute the timer interrupt processing here. In；a real system，some kind of status indication would have to be checked；before the timer interrupt handler could be called

23、. */;BL clearflag;清除中断标志位很重要（自己移植时加，位置与否恰当？）BL _tx_timer_interrupt ；定期中断解决函数;；/* 系统线程上下文环境恢复函数 */B _tx_thread_context_restore_tx_timer_interrupt所属文献调用者开关量tx_timin.s启动代码无该函数重要是中断后将系统时钟加1，时间切片减1。定期某些比较多，没有完全看明白。IMPORT _tx_timer_time_sliceIMPORT _tx_timer_system_clockIMPORT _tx_timer_current_ptrIMPORT

24、_tx_timer_list_startIMPORT _tx_timer_list_endIMPORT _tx_timer_expired_time_sliceIMPORT _tx_timer_expiredIMPORT _tx_timer_threadIMPORT _tx_thread_current_ptrIMPORT _tx_thread_time_sliceIMPORT _tx_thread_resumeIMPORT _tx_thread_preempt_disable;PRESERVE8AREA |C$code|，CODE，READONLY|x$codeseg| DATA;VOID

25、_tx_timer_interrupt(VOID);EXPORT _tx_timer_interrupt_tx_timer_interrupt;；/* Upon entry to this routine，it is assumed that context save has already；been called，and therefore the compiler scratch registers are available；for use. */;；/* Increment the system clock. */；_tx_timer_system_clock+;LDR a2，pc，#

26、SYSTEM_CLOCK-.-8 ；获得系统时钟地址LDR a1，a2，#0 ；获得系统时钟ADD a1，a1，#1 ；将系统时钟加1STR a1，a2，#0 ；存储新系统时钟时间;；/* Test for time-slice expiration. */；if (_tx_timer_time_slice)；;LDR a4，pc，#TIME_SLICE-.-8 ；获得链表中定期切片数地址LDR a3，a4，#0 ；获得定期切片数值CMP a3，#0 ；定期切片与否有效，0有效，=0无效BEQ _tx_timer_no_time_slice ；=0时，跳到_tx_timer_no_time_s

27、lice处；/* 时间切片减1. */；_tx_timer_time_slice-;SUB a3，a3，#1 ；时间切片值减1STR a3，a4，#0 ；存储新时间切片值;；/* 检查与否到期. */；if (_tx_timer_time_slice = 0);CMP a3，#0 ；0还是=0？BNE _tx_timer_no_time_slice ；如果0,;当没有定期切片时，将定期切片数标志位置1，表达链表中没有切片了。；/* Set the time-slice expired flag. */；_tx_timer_expired_time_slice = TX_TRUE;LDR a4，

28、pc，#EXPIRED_TIME_SLICE-.-8 ；获得定期切片数与否为0标志地址MOV a1，#1 ；将标志设为1STR a1，a4，#0 ；设立届时标志;；;_tx_timer_no_time_slice;；/* Test for timer expiration. */；if (*_tx_timer_current_ptr)；;LDR a2，pc，#TIMER_CURRENT_PTR-.-8 ；获得是_tx_timer_current_ptr地址;而TIMER_DECLARE TX_INTERNAL_TIMER *_tx_timer_current_ptr;LDR a1，a2，#0

29、；获得当前_tx_timer_current_ptrLDR a3，a1，#0 ；获得定期列表入口定期切片指针CMP a3，#0 ;链表中与否有定期切片存在BEQ _tx_timer_no_timer ；不存在，调用_tx_timer_no_time将；_tx_timer_current_ptr+;；/* Set expiration flag. */；_tx_timer_expired = TX_TRUE;LDR a4，pc，#EXPIRED-.-8 ；Pickup expriation flag addressMOV a3，#1 ；Build expired valueSTR a3，a4，#

30、0 ；Set expired flagB _tx_timer_done ；Finished timer processing;；else；_tx_timer_no_timer;；/* No timer expired，increment the timer pointer. */；_tx_timer_current_ptr+;ADD a1，a1，#4 ；Move to next timer;；/* Check for wrap-around. */；if (_tx_timer_current_ptr = _tx_timer_list_end);LDR a4，pc，#LIST_END-.-8 ；

31、Pickup addr of timer list endLDR a3，a4，#0 ；Pickup list endCMP a1，a3 ；Are we at list end?BNE _tx_timer_skip_wrap ；No，skip wrap-around logic;；/* Wrap to beginning of list. */；_tx_timer_current_ptr = _tx_timer_list_start;LDR a4，pc，#LIST_START-.-8 ；Pickup addr of timer list startLDR a1，a4，#0 ；Set curren

32、t pointer to list start;_tx_timer_skip_wrap;STR a1，a2，#0 ；Store new current timer pointer；;_tx_timer_done;；/* See if anything has expired. */；if (_tx_timer_expired_time_slice) | (_tx_timer_expired)；;LDR a4，pc，#EXPIRED_TIME_SLICE-.-8 ；Pickup addr of expired flagLDR a3，a4，#0 ；Pickup time-slice expired

33、 flagCMP a3，#0 ；Did a time-slice expire?BNE _tx_something_expired ；If non-zero，time-slice expiredLDR a2，pc，#EXPIRED-.-8 ；Pickup addr of other expired flagLDR a1，a2，#0 ；Pickup timer expired flagCMP a1，#0 ；Did a timer expire?BEQ _tx_timer_nothing_expired ；No，nothing expired;_tx_something_expired;STR l

34、r，sp，#-4！；Save the lr register on the stack;；/* Did a timer expire?*/；if (_tx_timer_expired)；;LDR a2，pc，#EXPIRED-.-8 ；Pickup addr of expired flagLDR a1，a2，#0 ；Pickup timer expired flagCMP a1，#0 ；Check for timer expirationBEQ _tx_timer_dont_activate ；If not set，skip timer activation;；/* Increment the

35、 preempt disable counter in preparation for ；thread resumption. */；_tx_thread_preempt_disable+;LDR a4，pc，#PREEMPT_DISABLE-.-8 ；Pickup addr of preempt disable LDR a3，a4，#0 ；Pickup actual flagADD a3，a3，#1 ；Incrment the preempt disable countSTR a3，a4，#0 ；Store it back;；/* Activate the system timer thre

36、ad. */；_tx_thread_resume(&_tx_timer_thread);LDR a1，pc，#TIMER_THREAD-.-8 ；Get timer thread control block addrBL _tx_thread_resume ；Call thread resume to wake up the；timer thread;；_tx_timer_dont_activate;；/* Did time slice expire?*/；if (_tx_timer_expired_time_slice)；;LDR a4，pc，#EXPIRED_TIME_SLICE-.-8

37、；Pickup addr of time-slice expired LDR a3，a4，#0 ；Pickup the actual flagCMP a3，#0 ；See if the flag is setBEQ _tx_timer_not_ts_expiration ；No，skip time-slice processing;；/* Time slice interrupted thread. */；if (!_tx_thread_time_slice()；_tx_timer_time_slice = _tx_thread_current_ptr - tx_time_slice;BL _

38、tx_thread_time_slice ；Call time-slice processingCMP a1，#0 ；Check return statusBNE _tx_timer_not_ts_expiration ；If time-sliced，skip reset processingLDR a2，pc，#CURRENT_PTR-.-8 ；Pickup addr of current thread pointerLDR a1，a2，#0 ；Pickup thread pointerLDR a3，a1，#24 ；Pickup fresh time-slice for thread；(a

39、fresh time slice was setup in ；the _tx_thread_time_slice function)LDR a4，pc，#TIME_SLICE-.-8 ；Pickup addr of time-slice variableSTR a3，a4，#0 ；Setup new time-slice;；;_tx_timer_not_ts_expiration;LDR a4，pc，#EXPIRED_TIME_SLICE-.-8 ；Pickup address of expired time-slice flagMOV a1，#0 ；Clear valueSTR a1，a4，

40、#0 ；Clear time-slice expired flag;LDR lr，sp，#4 ；Recover lr register;；;_tx_timer_nothing_expired;MOV pc，lr ；Return to caller;TIME_SLICEDCD _tx_timer_time_sliceSYSTEM_CLOCKDCD _tx_timer_system_clockTIMER_CURRENT_PTRDCD _tx_timer_current_ptrLIST_STARTDCD _tx_timer_list_startLIST_ENDDCD _tx_timer_list_e

41、ndEXPIRED_TIME_SLICEDCD _tx_timer_expired_time_sliceEXPIREDDCD _tx_timer_expiredTIMER_THREADDCD _tx_timer_threadCURRENT_PTRDCD _tx_thread_current_ptrTHREAD_TIME_SLICEDCD _tx_thread_time_sliceRESUMEDCD _tx_thread_resumePREEMPT_DISABLEDCD _tx_thread_preempt_disableEND_tx_initialize_high_level()VOID _tx_initialize_high_level(VOID)所属文献调用者开关量tx_ihl.c启动代码无重要时对某些与硬件无关变量进行初始化，其中重要实现了线程初始化；定期初始化，这里定期也是一种线程，且优先级为最高0；尚有对信号量、队列、时间标志、块池、和字节池初始化。/*进行某些高档初始化*/_tx_initialize_high_level();VOID _tx_initialize_high_level(VOID)/* Initialize the event log，if enabled. */TX