kernel.h

#ifndef KERNEL_H
#define KERNEL_H

// Debug option
// #define       _DEBUG

/*********************************************************/
/** Global variabels and definitions                     */
/*********************************************************/

#include <stdlib.h>
#ifdef texas_dsp
  
#define CONTEXT_SIZE    (34 - 2)
  
#else
  
#define CONTEXT_SIZE    13 
#define STACK_SIZE      100
  
#endif
  
#define TRUE    1
#define FALSE   !TRUE
  
#define RUNNING 1
#define INIT    !RUNNING
  
#define FAIL    0
#define SUCCESS 1
#define OK      1
  
#define DEADLINE_REACHED        0
#define NOT_EMPTY               0
  
#define SENDER          +1
#define RECEIVER        -1

typedef int             exception;
typedef int             bool;
typedef unsigned int    uint;
typedef int 		    action;

struct  l_obj;         // Forward declaration
  
  // Task Control Block, TCB
#ifdef texas_dsp

typedef struct {
    void	(*PC)();
    uint	*SP;
    uint	Context[CONTEXT_SIZE];
    uint	StackSeg[STACK_SIZE];
    uint	DeadLine;
} TCB;

#else

typedef struct {
    uint    Context[CONTEXT_SIZE];
    uint    *SP;
    void    (*PC)();
    uint    SPSR;
    uint    StackSeg[STACK_SIZE];
    uint    DeadLine;
} TCB;
  
#endif

// Message items
typedef struct msgobj {
    char            *pData;
    exception       Status;
    struct l_obj    *pBlock;
    struct msgobj   *pPrevious;
    struct msgobj   *pNext;
} msg;

// Mailbox structure
typedef struct {
    msg             *pHead;
    msg             *pTail;
    int             nDataSize;
    int             nMaxMessages;
    int             nMessages;
    int             nBlockedMsg;
} mailbox;

// Generic list item
typedef struct l_obj {
    TCB            *pTask;
    uint           nTCnt;
    msg            *pMessage;
    struct l_obj   *pPrevious;
    struct l_obj   *pNext;
} listobj;

// Generic list
typedef struct {
    listobj        *pHead;
    listobj        *pTail;
} list;

// Function prototypes

// Task administration
int        init_kernel(void);
exception  create_task(void (*body)(), uint d);
void       terminate(void);
void       run(void);

// Communication
mailbox*	    create_mailbox( uint nMessages, uint nDataSize );
int             no_messages( mailbox* mBox );

exception       send_wait( mailbox* mBox, void* pData );
exception       receive_wait( mailbox* mBox, void* pData );

exception	    send_no_wait( mailbox* mBox, void* pData );
int             receive_no_wait( mailbox* mBox, void* pData );

// Timing
exception	    wait(uint nTicks);
void            set_ticks( uint no_of_ticks );
uint            ticks(void );
uint		    deadline(void);
void            set_deadline(uint nNew);

//Interrupt
extern void     isr_off(void);
extern void     isr_on(void);
// Stores DSP registers in TCB pointed to by Running
extern void     SaveContext(void);	
// Restores DSP registers from TCB pointed to by Running
extern void     LoadContext(void);	
  
#endif