uc/os-ii移植笔记

(此部分参考了tomato的介绍)

os_cpu.h

与编译器相关的数据类型

typedef   unsigned char   BOOLEAN;

typedef   unsigned char   INT8U;                    /* Unsigned  8 bit quantity */

typedef   signed   char   INT8S;                    /* Signed    8 bit quantity  */

typedef   unsigned short   INT16U;                   /* Unsigned 16 bit quantity */

typedef   signed   short  INT16S;                   /* Signed   16 bit quantity */

typedef   unsigned int     INT32U;                   /* Unsigned 32 bit quantity */

typedef   signed   int    INT32S;                   /* Signed   32 bit quantity  */

typedef   float           FP32;                     /* Single precision floating point*/

typedef   double         FP64;                     /* Double precision floating point */

typedef   unsigned int    OS_STK;                   /* 堆栈类型为32位 Each stack entry is 32-bit wide */

typedef   unsigned int    OS_CPU_SR;                /* Define size of CPU status register (PSR = 32 bits) */

与ARM 处理器相关的代码

#define  OS_CRITICAL_METHOD   3      //进入临界段的方法

#if      OS_CRITICAL_METHOD == 3

#define  OS_ENTER_CRITICAL()   {cpu_sr = OS_CPU_SR_Save();} //关中断

#define  OS_EXIT_CRITICAL()     {OS_CPU_SR_Restore(cpu_sr);} //开中断

#endif

#if  OS_CRITICAL_METHOD == 3

OS_CPU_SR   OS_CPU_SR_Save(void);

void        OS_CPU_SR_Restore(OS_CPU_SR cpu_sr);

#endif

void       OSCtxSw(void);

void       OSIntCtxSw(void);

void       OSStartHighRdy(void);

设置堆栈的增长方向

#define  OS_STK_GROWTH    1  /*堆栈由高地址向低地址增长*/

OS_CPU_C.C

用C 语言编写六个操作系统相关的函数

OS_STK  *OSTaskStkInit ( void   (*task)(void *p_arg), 

void   *p_arg, 

OS_STK  *ptos,

INT16U  opt)

{

    OS_STK  *stk;

    (void)opt;                                   /* 'opt' is not used, prevent warning                 */

    stk       = ptos;                            /* Load stack pointer                                 */

                                                 /* Registers stacked as if auto-saved on exception    */

    *(stk)   = (INT32U)0x01000000L;             /* xPSR                                               */

    *(--stk)  = (INT32U)task;                    /* Entry Point                                        */

    *(--stk)  = (INT32U)0xFFFFFFFEL;             /* R14 (LR) (init value will cause fault if ever used)*/

    *(--stk)  = (INT32U)0x12121212L;             /* R12                                                */

    *(--stk)  = (INT32U)0x03030303L;             /* R3                                                 */

    *(--stk)  = (INT32U)0x02020202L;             /* R2                                                 */

    *(--stk)  = (INT32U)0x01010101L;             /* R1                                                 */

    *(--stk)  = (INT32U)p_arg;                   /* R0 : argument                                      */

                                                 /* Remaining registers saved on process stack         */

    *(--stk)  = (INT32U)0x11111111L;             /* R11                                                */

    *(--stk)  = (INT32U)0x10101010L;             /* R10                                                */

    *(--stk)  = (INT32U)0x09090909L;             /* R9                                                 */