/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*
*                              (c) Copyright 2006-2012, Micrium, Weston, FL
*                                          All Rights Reserved
*
*                                           ARM Cortex-M0 Port
*
* File      : os_cpu.h
* Version   : V2.92.07.00
* By        : JJL
*             BN
*             MD
*
* For       : ARMv6M Cortex-M0
* Mode      : Thumb2
* Toolchain : GNU C Compiler
*********************************************************************************************************
*/

#ifndef  OS_CPU_H
#define  OS_CPU_H


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

#ifndef  OS_CPU_EXCEPT_STK_SIZE
#define  OS_CPU_EXCEPT_STK_SIZE    128u          /* Default exception stack size is 128 OS_STK entries */
#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 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;                                  /* Each stack entry is 32-bit wide                      */
typedef unsigned int   OS_CPU_SR;                               /* Define size of CPU status register (PSR = 32 bits)   */

/*
*********************************************************************************************************
*                                              Cortex-M0
*                                      Critical Section Management
*
* 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.
*             NOT IMPLEMENTED
*
* 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.
*             NOT IMPLEMENTED
*
* 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.
*********************************************************************************************************
*/

#define  OS_CRITICAL_METHOD   3u

#if OS_CRITICAL_METHOD == 3u
#define  OS_ENTER_CRITICAL()  {cpu_sr = OS_CPU_SR_Save();}
#define  OS_EXIT_CRITICAL()   {OS_CPU_SR_Restore(cpu_sr);}
#endif

/*
*********************************************************************************************************
*                                        Cortex-M0 Miscellaneous
*********************************************************************************************************
*/

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

#define  OS_TASK_SW()         OSCtxSw()

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

OS_CPU_EXT  OS_STK   OS_CPU_ExceptStk[OS_CPU_EXCEPT_STK_SIZE];
OS_CPU_EXT  OS_STK  *OS_CPU_ExceptStkBase;

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

#if OS_CRITICAL_METHOD == 3u                                    /* See OS_CPU_A.ASM                                     */
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);

void       OS_CPU_PendSVHandler(void);

                                                                /* See OS_CPU_C.C                                       */
void       OS_CPU_SysTickHandler(void);
void       OS_CPU_SysTickInit(INT32U  cnts);
#endif
