/*
*********************************************************************************************************
*                                               uC/OS-II
*                                        The Real-Time Kernel
*
*                         (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
*                                          All Rights Reserved
*
* 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)
*********************************************************************************************************
*/

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 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                    */

typedef unsigned int   OS_STK;                   /* Each stack entry is 32-bit wide                    */
typedef unsigned int   OS_CPU_SR;                /* Define size of CPU status register (PSW = 16 bits) */

#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

#define  OS_CRITICAL_METHOD    3

#if      OS_CRITICAL_METHOD == 1
#elif    OS_CRITICAL_METHOD == 2
#elif    OS_CRITICAL_METHOD == 3
#define  OS_ENTER_CRITICAL()  (cpu_sr = OSCPUSaveSR())    /* Disable interrupts                        */
#define  OS_EXIT_CRITICAL()   (OSCPURestoreSR(cpu_sr))    /* Enable  interrupts                        */
#endif

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

#define  OS_TASK_SW           OSCtxSw

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

//OS_CPU_EXT  INT8U  OSTickDOSCtr;       /* Counter used to invoke DOS's tick handler every 'n' ticks    */

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

#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
__inline OS_CPU_SR OSCPUSaveSR(void)
{
	unsigned old_psr, new_psr;
	__asm
	{
		MRS old_psr,CPSR
		ORR new_psr,old_psr,#0x80
		MSR CPSR_c,new_psr
	}
	return old_psr;
}
__inline void OSCPURestoreSR(OS_CPU_SR cpu_sr)
{
	__asm
	{
		MSR CPSR_c,cpu_sr
	}
}
#endif