os_cpu.h

《嵌入式系统-使用HCS12微控制器的设计与应用》在CodeWarrior开发环境下的源程序。

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                        The Real-Time Kernel
*
*                         (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
*                                          All Rights Reserved
*
*                                       80x86/80x88 Specific code
*                                          LARGE MEMORY MODEL
*
*                                          Borland C/C++ V4.51
*
* File         : OS_CPU.H
* By           : Jean J. Labrosse
*********************************************************************************************************
*/

#ifdef  OS_CPU_GLOBALS
#define OS_CPU_EXT
#else
#define OS_CPU_EXT  extern
#endif

/*
*********************************************************************************************************
*                                              DATA TYPES
*                                         (Compiler Specific)
*********************************************************************************************************
*/
#ifndef _TYPES
#define _TYPES

typedef unsigned char  BOOLEAN;
typedef unsigned char  INT8U;                    /* Unsigned  8 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                           */
typedef float          FP32;                     /* Single precision floating point                    */
typedef double         FP64;                     /* Double precision floating point                    */

//定义了S12 CPU中的堆栈入口的数据长度
typedef unsigned int   OS_STK;
//typedef unsigned int   OS_STK;                 /* Each stack entry is 16-bit wide                    */
//定义了S12 CPU中的CCR的长度
typedef unsigned char  OS_CPU_SR;
//typedef unsigned short OS_CPU_SR;              /* Define size of CPU status register (PSW = 16 bits) */

#endif

//去掉重复定义
//#define BYTE           INT8S                   /* Define data 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

/* 
*********************************************************************************************************
*                              Intel 80x86 (Real-Mode, Large Model)
*
* Method #1:  Disable/Enable interrupts using simple instructions.  After critical section, interrupts
*             will be enabled even if they were disabled before entering the critical section.
*
* Method #2:  Disable/Enable interrupts by preserving the state of interrupts.  In other words, if 
*             interrupts were disabled before entering the critical section, they will be disabled when
*             leaving the critical section.
*
* Method #3:  Disable/Enable interrupts by preserving the state of interrupts.  Generally speaking you
*             would store the state of the interrupt disable flag in the local variable 'cpu_sr' and then
*             disable interrupts.  'cpu_sr' is allocated in all of uC/OS-II's functions that need to 
*             disable interrupts.  You would restore the interrupt disable state by copying back 'cpu_sr'
*             into the CPU's status register.
*********************************************************************************************************
*/

//定义进入临界区代码的方法
//#define  OS_CRITICAL_METHOD    2
#define  OS_CRITICAL_METHOD      3

//修改方法1
#if      OS_CRITICAL_METHOD == 1
#define  OS_ENTER_CRITICAL()   asm  sei                            /* Disable interrupts */
#define  OS_EXIT_CRITICAL()    asm  cli                            /* Enable  interrupts */
#endif

//修改方法2
#if      OS_CRITICAL_METHOD == 2
#define  OS_ENTER_CRITICAL()   asm  pshc; sei                      /* Disable interrupts */
#define  OS_EXIT_CRITICAL()    asm  pulc                           /* Enable  interrupts */
#endif

//修改方法3
#if      OS_CRITICAL_METHOD == 3
#define  OS_ENTER_CRITICAL()   asm tpa; asm sei; asm staa cpu_sr   /* Disable interrupts */
#define  OS_EXIT_CRITICAL()    asm ldaa cpu_sr; asm tap            /* Enable  interrupts */
#endif

//保存堆栈指针的宏定义
#define OS_SAVE_SP();   if(OSIntNesting==1) {asm ldx OSTCBCur; asm sts 0,x;}

/*
*********************************************************************************************************
*                                (Real-Mode, Large Model) Miscellaneous
*********************************************************************************************************
*/

#define  OS_STK_GROWTH        1                       /* Stack grows from HIGH to LOW memory   */

#define  uCOS                 0x80                    /* Interrupt vector # used for context switch  */

//定义任务切换的指令
#define  OS_TASK_SW()         asm swi

/*
*********************************************************************************************************
*                                            GLOBAL VARIABLES
*********************************************************************************************************
*/

//编译不通过，去掉DOS相关代码
//OS_CPU_EXT  INT8U  OSTickDOSCtr;       /* Counter used to invoke DOS's tick handler every 'n' ticks  */

/*
*********************************************************************************************************
*                                              PROTOTYPES
*********************************************************************************************************
*/

//void  OSTaskStkInit_FPE_x86(OS_STK **pptos, OS_STK **ppbos, INT32U *psize);

//#if OS_CRITICAL_METHOD == 3                /* Allocate storage for CPU status register */
//OS_CPU_SR  OSCPUSaveSR(void);
//void       OSCPURestoreSR(OS_CPU_SR cpu_sr);
//#endif