#include <unistd.h> 
#include <stdlib.h>
#include <stdio.h> 
#include "dllist.h" 
#include "kt.h"

#include "simulator.h"
#include "scheduler.h"

Dllist readyq;
extern char *Argv[];
struct PCB_struct *Current_pcb;
int Idle;


void *InitUserProcess(void *arg)
{

	int registers[NumTotalRegs];
        int i;
	struct PCB_struct *pcb;
	char *fname;
	char **argv;
	int *user_argv;

	argv = (char **)arg;
	fname = argv[0];

	/*
	 * begin initial setup for user state
	 */
        bzero(main_memory, MemorySize);

        if (load_user_program(fname) < 0) {
                fprintf(stderr,"Can't load program.\n");
                exit(1);
        }
	/*
 	 * allocate a pcb for the first process
 	 */
	pcb = (struct PCB_struct *)malloc(sizeof(struct PCB_struct));
	if(pcb == NULL) {
		exit(1);
	}

        for (i=0; i < NumTotalRegs; i++)
                pcb->registers[i] = 0;

        /* set up the program counters and the stack register */

        pcb->registers[PCReg] = 0;
        pcb->registers[NextPCReg] = 4;

        /* need to back off from top of memory */
        /* 12 for stack frame */
        pcb->registers[StackReg] = MemorySize - 12;

	/*
 	 * use zero as mem_base in first lab
 	 */
	// InitUserArgs(registers,argv,0);
	user_argv = MoveArgsToStack(pcb->registers,argv,0);
	InitCRuntime(user_argv,pcb->registers,argv,0);

	/* end user setup */


	/*
 	 * put it at the end of the readyq
 	 */
	dll_append(readyq,new_jval_v((void *)pcb));

	kt_exit(NULL);

	return(NULL);

}

void ScheduleProcess()
{
	printf("scheduler called\n");
	// scheduler code goes here
	return;
}
	
void
SysCallReturn(struct PCB_struct *pcb, int return_val)
{
	printf("SysCallReturn called\n");
	// syscallreturn code goes here
	kt_exit(NULL);
}