pcb.h

#ifndef _PCB_H
#define _PCB_H

#include "file.h"
#include "filesys_struct.h"
#include "filesys.h"
#include "rtc.h"
#include "term_driver.h"
#include "keyboard.h"
#include "types.h"
#include "lib.h"

#define FILE_ARRAY_SIZE 8

typedef void (*dz_op)(void);
typedef void (*seg_op)(void);
typedef void (*intr_op)(void);
typedef void (*alarm_op)(void);
typedef void (*user1_op)(void);

typedef struct sig_ops {
	dz_op 		div_zero;
	seg_op		seg_fault;
	intr_op		interrupt;
	alarm_op	alarm;
	user1_op	user;
} sig_ops;

typedef struct pcb {
	int32_t pid;

	uint32_t ESP;	// this is for switching back and forth between terminals
	uint32_t EBP;

	uint32_t switch_ESP;  // used to restore the parent task's stack when halting
	uint32_t switch_EBP;

	uint32_t program_start; // where the starting point for the program is

	/* the file array (Appendix A 7.2) */
	struct pcb * parent;	// the parent task's pcb pointer
	struct pcb * child;
	uint8_t arg[FILE_NAME_LENGTH];
	sig_ops signal_ops;
	uint8_t sig_pending;
	uint8_t sig_masked;
	file_t file_array[FILE_ARRAY_SIZE];
} pcb_t; //no alignment here as pcb is not 8 kb. Align the task struct which includes the pcb. 

/* "not implemented" */
int32_t ni_open(const uint8_t *filename);
int32_t ni_read(int32_t fd, void *buf, int32_t nbytes);
int32_t ni_write(int32_t fd, const void *buf, int32_t nbytes);
int32_t ni_close(int32_t fd);

/* reset all processes, called before first shell execution */
void ready_all_processes();

/* initializes a pcb */
int32_t init_pcb(pcb_t * pcb, pcb_t * parent,  int32_t pid, uint32_t start, uint8_t * arg);

/* adds a file to a pcb's file array */
int32_t add_file(pcb_t * pcb, file_t file);

/* closes a file in a pcb's file array */
int32_t close_file(pcb_t * pcb, int32_t fd);

/* unitializes a pcb */
int32_t close_pcb(pcb_t * pcb);

/* helper functions */

#endif