uCOSII在ARM微处理器上的移植和编译课程设计报告书.docx

1、uCOSII在ARM微处理器上的移植和编译课程设计报告书ARM原理与应用报告一、设计内容1.用ADS1.2 IDE软件进行程序代码编译设计，生成可执行的输出文件，并显示运行结果，实现uC/OS-II内核在ARM处理器上移植。2.uC/OS-II在ARM微处理器上的移植及编译。二、 设计目的与要求目的:ARM原理与应用课程设计是学生理论联系实际的重要实践教学环节，是对学生进行的一次专业训练，也是对学生掌握和应用嵌入式系统相关知识能力的有效测试。通过ARM原理与应用课程设计，使学生初步了解嵌入式系统软件开发的一般过程和基本设计方法，使学生进一步巩固和加深所学的专业理论知识，培养学生文献查阅、报告撰

2、写等基本技能；培养学生独立分析和解决工程实际问题的能力；培养学生的团队协作精神、创新意识、严肃认真的治学态度和严谨求实的工作作风。要求:1) 了解uC/OS-II 内核的主要结构。2) 掌握将uC/OS-II 内核移植到ARM 处理器上的基本方法。3）在给定的设备（UP-TECH PXA270-S嵌入式开发平台、PC 机 、WinXP、ADS1.2 集成开发环境、仿真器驱动程序、超级终端通讯程序）上加以实验，学会自己分析、找出解决问题的方法。4）对设计中遇到的问题和困难，独立思考，查阅资料，分析、观察、判断、试验、再判断以寻找答案。5）分析结果，写出设计总结报告论述自己的观点，并应将参考资料列

3、在报告后面以备查询。内容尽量翔实(如上机过程、环境搭建)，其中必须有按自己所理解、用自己的语言所描述的内容。三、 设计环境或器材、原理与说明环境:硬件：PC机，博创UP-TECHPXA27-S目标板ARM7TDMI微处理器，串口线，并口JTAG 转换线；软件：MS.Virtual.PC.2004，Windows XP系统，ADS1.2 IDE编译环境，LPC2000 Flash Utility烧写程序、超级终端通讯程序.原理与说明:1.ARM原理与应用课程设计题目涉及ARM应用的诸多方面，须经过思考和认真的学习，有一定难度，在深度方面主要要求学生对具体ARM指令的分析理解，目标板ARM处理器的

4、硬件认识了解，ADS1.2 IDE软件的操作能力，解读uC/OS-II 内核的自学能力以及自我解决问题的能力。2.c/os-ii是一个完整的，可移植、可固化、可裁减的占先式实时多任务内核，它功能强大，支持56个用户任务，支持信号量、邮箱、消息队列等多种常用的进程间通信机制。公开源代码，程序可读性强、移植性好，同时可免费获得。lpc2119是由philips生产的一款32位arm7tdmi-s微处理器，其核心为高性能的32位risc体系结构，并具有高密度的16位指令集和极低的功耗。具有零等待128K字节的片内Flash，16k的Sram，无需扩展存储器，使系统更为简单、可靠。四、 设计过程（步骤

5、）或程序代码源代码:1. OS_CPU.H文件该文件定义了和处理器相关的定义及一些全局函数声明。由于ARM7 处理器字长为32位，半字长为16位，字节为8位，因此在OS_CPU.h文件修改了一些相关定义以确保uC/OS-的可移植性：#ifndef _OS_CPU_H_#define _OS_CPU_H_#ifdef OS_CPU_GLOBALS#define OS_CPU_EXT#else#define OS_CPU_EXT extern#endiftypedef unsigned char BOOLEAN;typedef unsigned char INT8U; /* Unsigned 8

6、bit quantity */typedef signed char INT8S; /* Signed 8 bit quantity */typedef unsigned int INT16U; /* Unsigned 16 bit quantity */typedef signed int INT16S; /* Signed 16 bit quantity */typedef unsigned long INT32U; /* Unsigned 32 bit quantity */typedef signed long INT32S; /* Signed 32 bit quantity */t

7、ypedef float FP32; /* Single precision floating point */typedef double FP64; /* Double precision floating point */typedef unsigned int OS_STK; /* Each stack entry is 16-bit wide */typedef unsigned int OS_CPU_SR; /* Define size of CPU status register (PSR = 32 bits) */#define BYTE INT8S /* Define dat

8、a types for backward compatibility . */#define UBYTE INT8U /* . to uC/OS V1.xx. Not actually needed for . */#define WORD INT16S /* . uC/OS-II. */#define UWORD INT16U#define LONG INT32S#define ULONG INT32U从上面定义可看出，uC/OS-代码不使用C的short，int和long等数据类型，这是因为它们是与编译器相关的，不可移植。uC/OS-需要先禁止中断再访问代码的临界段，并且在访问后重新允许中

9、断，这就使得uC/OS-能够保护临界段代码免受多任务或中断服务例程的破坏。uC/OS-对关中断以及开中断的宏定义如下：#define OS_CRITICAL_METHOD 3#if OS_CRITICAL_METHOD = 3 /* critical section macros use method 3 (save to local var cpu_sr) */extern int INTS_OFF(void); /* ASM routines to twiddle bits */extern void INTS_ON(void);#define OS_ENTER_CRITICAL() cp

10、u_sr = INTS_OFF(); #define OS_EXIT_CRITICAL() if(cpu_sr = 0) INTS_ON(); #else #error please define critical method#endif#define OS_STK_GROWTH 1 /* Stack grows from HIGH to LOW memory on 80x86 */#define OS_TASK_SW() OSCtxSw()#endif /*_OS_CPU_H_*/uC/OS-可以处理从下往上长以及从上往下长两种堆栈方式，但由于ARM处理器的堆栈都是从上往下生长，也就是高地

11、址到低地址的生长方向，因此宏定义如下：#define OS_STK_GROWTH 1 /*堆栈从上往下增长,1向上,0向下*/2. OS_CPU_C.C文件在这个文件里主要是OSTaskStkInit()函数和一些钩子函数，需要关心的是OSTaskStkInit()。OSTaskStkInit()是任务堆栈初始化函数，它由任务建立函数OSTaskCreateExt()调用，用于初始化任务的堆栈，堆栈的结构初始化成看起来刚刚发生过中断一样，所有的寄存器都被入栈。在ARM体系结构下，任务堆栈空间由高至低依次将保存着pc、lr、r12、r11、r10、r1、r0、cpsr、spsr。OSTaskSt

12、kInit()函数有四个参数，task，pdata，ptos，opt，它们和建立任务所使用的参数是一致的。函数返回堆栈指针所指的地址。当我们使用OSTaskCreateExt()来建立任务时，就把上述四个参数传递给OSTaskStkInit()函数，初始化好堆栈，再返回给OSTaskCreateExt()堆栈指针，继续走下去。OSTaskStkInit()函数代码最后，使用R0来传递参数，这是符合ARM汇编的规范，使用R0来传递第一个参数。#include includes.h /* from uCOS directory */#include ipport.h /* from Interni

13、che directory */* ARM CPU supervisor mode for PSR registers, with INTs enabled */#define SUPMODE 0x13OS_STK * OSTaskStkInit (void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt) unsigned int * stk; stk = (unsigned int *)ptos; /* 加载堆栈指针 */ /USE_ARG(opt); opt+; /* build a stack for the new t

14、ask */*建立任务环境，ADS1.2使用满递减堆栈*/ *-stk = (unsigned int) task; /* pc */ *-stk = (unsigned int) task; /* lr */ *-stk = 12; /* r12 */ *-stk = 11; /* r11 */ *-stk = 10; /* r10 */ *-stk = 9; /* r9 */ *-stk = 8; /* r8 */ *-stk = 7; /* r7 */ *-stk = 6; /* r6 */ *-stk = 5; /* r5 */ *-stk = 4; /* r4 */ *-stk =

15、3; /* r3 */ *-stk = 2; /* r2 */ *-stk = 1; /* r1 */ *-stk = (unsigned int) pdata; /* r0, 第一个参数使用R0传递*/ *-stk = (SUPMODE); /* cpsr */ *-stk = (SUPMODE); /* spsr */ return (OS_STK *)stk);#if OS_CPU_HOOKS_ENvoid OSTaskCreateHook (OS_TCB *ptcb) /*任务创建钩子函数,当任务被创建时调用该函数*/ ptcb = ptcb; /* ptcb没有用,是为了防止编译器警

16、告*/void OSTaskDelHook (OS_TCB *ptcb) /*任务删除钩子函数,当任务被删除时调用该函数*/ptcb = ptcb; /* ptcb没有用,是为了防止编译器警告*/void OSTaskSwHook (void) /*任务切换函数,可以在执行其他操作时进行上下文切换。*/void OSTaskStatHook (void) /*任务统计钩子函数*/void OSTimeTickHook (void)void OSTCBInitHook (OS_TCB *ptcb) ptcb = ptcb; /* Prevent Compiler warning */void O

17、STaskIdleHook (void)void OSInitHookEnd (void)void OSInitHookBegin (void)#endif3.OS_CPU_A.S文件该文件的是移植的关键所在，在本文件中必须完成四个函数的编写工作，它们分别为OSIntCtxSw( )，OSCtxSw( )， OSStartHighRdy( )和OSTickISR( )。其中前两个函数是重中之重，它们必须用汇编语言编写，主要完成任务环境的切换工作。 AREA |subr|, CODE, READONLY EXPORT OSIntCtxSw EXPORT OS_TASK_SW EXPORT INT

18、S_OFF EXPORT INTS_ONINTS_OFF mrs r0, cpsr ; current CSR mov r1, r0 ; make a copy for masking orr r1, r1, #0xC0 ; mask off int bits msr CPSR_cxsf, r1 ; disable ints (IRQ and FIQ) and r0, r0, #0x80 ; return FIQ bit from original CSR mov pc,lr ; returnINTS_ON mrs r0, cpsr ; current CSR bic r0, r0, #0xC

19、0 ; mask on ints msr CPSR_cxsf, r0 ; enable ints (IRQ and FIQ) mov pc,lr ; return ; External symbols we need the addresses of IMPORT OSTCBCuraddr_OSTCBCur DCD OSTCBCur IMPORT OSTCBHighRdyaddr_OSTCBHighRdy DCD OSTCBHighRdy IMPORT OSPrioCuraddr_OSPrioCur DCD OSPrioCur IMPORT OSPrioHighRdyaddr_OSPrioHi

20、ghRdy DCD OSPrioHighRdy IMPORT IRQStack ;FIQ_STACKOSIntCtxSw; post FIQ Context switcher. This is called from OSIntExit when a hooked ISR; wants to return in the context of another task. We load the new tasks context; (from OSPrioHighRdy) and do the return from interrupt. ; Get pointer to stack where

21、 ISR_FiqHandler saved interrupted context ; ISR entry only saves first seven regs and LR. ; ;add r7, sp, #24 ; save pointer to register file, we must adjust this pointer to the position that just Enter Interrupt LDR sp, =IRQStack ;IRQ_STACK ;test to del it sub r7, sp, #4 ;r7 is the position that jus

22、t Enter Interrupt ; Change ARM CPU to SVC mode for stack operations. ; This gets the CPU off the interrupt stack and back to the ; interrupted tasks stack, which is the one we want to alter. ; mrs r1, SPSR ; get suspended PSR orr r1, r1, #0xC0 ; disable IRQ, FIQ. msr CPSR_cxsf, r1 ; switch mode (sho

23、ld be SVC_MODE) ; PSR, SP, LR regs are now restored to the interrupted SVC_MODE. ; now set up the tasks stack frame as OS_TASK_SW does.; ldr r0, r7, #52 ; get IRQs LR (tasks PC) from IRQ stack /r0-r12 ldr r0, r7 ; get IRQs LR (tasks PC) from IRQ stack sub r0, r0, #4 ; Actual PC address is (saved_LR

24、- 4) STMFD sp!, r0 ; save task PC STMFD sp!, lr ; save LR sub lr, r7, #52 ;/we save the r0-r12 when we enter IRQ.; mov lr, r7 ; save FIQ stack ptr in LR (going to nuke r7) ldmfd lr!, r0-r12 ; get saved registers from FIQ stack STMFD sp!, r0-r12 ; save registers on task stack ; save PSR and PSR for t

25、ask on tasks stack MRS r4, CPSR bic r4, r4, #0xC0 ; leave interrupt bits in enabled mode STMFD sp!, r4 ; save tasks current PSR MRS r4, SPSR STMFD sp!, r4 ; SPSR too ; OSPrioCur = OSPrioHighRdy / change the current process LDR r4, addr_OSPrioCur LDR r5, addr_OSPrioHighRdy LDRB r6, r5 STRB r6, r4 ; G

26、et preempted taskss TCB LDR r4, addr_OSTCBCur LDR r5, r4 STR sp, r5 ; store sp in preempted taskss TCB ; Get new task TCB address LDR r6, addr_OSTCBHighRdy LDR r6, r6 LDR sp, r6 ; get new tasks stack pointer ; OSTCBCur = OSTCBHighRdy STR r6, r4 ; set new current task TCB address LDMFD sp!, r4 MSR SP

27、SR_cxsf, r4 LDMFD sp!, r4 BIC r4, r4, #0xC0 ; we must exit to new task with ints enabled MSR CPSR_cxsf, r4 LDMFD sp!, r0-r12, lr, pc; void OS_TASK_SW(void) ; Perform a context switch.; On entry, OSTCBCur and OSPrioCur hold the current TCB and priority; and OSTCBHighRdy and OSPrioHighRdy contain the

28、same for the task; to be switched to.; The following code assumes that the virtual memory is directly; mapped into physical memory. If this is not true, the cache must ; be flushed at context switch to avoid address aliasing.OS_TASK_SW STMFD sp!, lr ; save pc STMFD sp!, lr ; save lr STMFD sp!, r0-r1

29、2 ; save registers and ret address MRS r4, CPSR STMFD sp!, r4 ; save current PSR MRS r4, SPSR STMFD sp!, r4 ; save SPSR ; OSPrioCur = OSPrioHighRdy LDR r4, addr_OSPrioCur LDR r5, addr_OSPrioHighRdy LDRB r6, r5 STRB r6, r4 ; Get current task TCB address LDR r4, addr_OSTCBCur LDR r5, r4 STR sp, r5 ; s

30、tore sp in preempted taskss TCB ; Get highest priority task TCB address LDR r6, addr_OSTCBHighRdy LDR r6, r6 LDR sp, r6 ; get new tasks stack pointer ; OSTCBCur = OSTCBHighRdy STR r6, r4 ; set new current task TCB address ; restore tasks mode regsiters LDMFD sp!, r4 MSR SPSR_cxsf, r4 LDMFD sp!, r4 M

31、SR CPSR_cxsf, r4 ; return in new task context LDMFD sp!, r0-r12, lr, pc; void OSStartHighRdy(void) ; Start the task with the highest priority; EXPORT OSStartHighRdyOSStartHighRdy LDR r4, addr_OSTCBCur ; Get current task TCB address LDR r5, addr_OSTCBHighRdy ; Get highest priority task TCB address LDR r5, r5