void load (char *filename, int priority){
PCB *pcb;
int SYS_CHECK_ERR = 0;
int SYS_LOAD_ERR = 0;
int PCB_CREATE_ERR = 0;
int pclass = 0;
int state = 0;
int len_p;
int offset_p;
int memory_size;
unsigned char load_address;
unsigned char execution_address;
if( name == NULL ) { // No name argument
printf("No name supplied.\n");
return PCB_CREATE_ERR;
}
else if( strlen(name) > 8 ) { // Name too long
printf("Specified process name too long.\n");
return PCB_CREATE_ERR;
}
else if ( !(priority >= -128 && priority <= 127) ) {
printf("Invalid priority.\n");
return PCB_CREATE_ERR;
}
else {
SYS_CHECK_ERR = sys_check_program("\0", filename, *len_p, *offset_p);
if( !SYS_CHECK_ERR == 0 ) {
printf("Program either doesn't exist or is invalid.\n");
return SYS_CHECK_ERR;
}
else {
memory_size = len_p;
load_address = (unsigned char*)sys_alloc_mem(memory_size);
execution_address = load_address + (unsigned char*)offset_p
// We've gotten what we needed and now we can apply it to a PCB.
pcb = PCB_setup(filename, priority, pclass);
// Place it in appropriate queue
PCB_CREATE_ERR = PCB_insert(PRIORITY_QUEUES[state], temp, state);
pcb->loadaddr = load_address;
pcb->execaddr = execution_address
context cp* = (context *) pcb->stack_top;
}
}
}
// loads a program into memory
void loadProgram(int argc, char *argv[]){ //name,fileName,priority,path
// sets up variables
static int count;
MEMDSC *tempMem;
unsigned char temptop;
char *dir, *name, *filename;
int size,offset,priority;
tcontext *tempContext;
unsigned int *tempCS,*tempIP;
STACKDSC *temp;
// initializes values
int err = 0;
PCB *newPCB = allocate_PCB();
tempMem=newPCB->memdsc;
dir = (char*) sys_alloc_mem(30 * sizeof(char));
name = (char*) sys_alloc_mem(30 * sizeof(char));
filename = (char*) sys_alloc_mem(30 * sizeof(char));
strcpy(dir,argv[4]);
strcpy(name,argv[1]);
strcpy(filename,argv[2]);
priority = atoi(argv[3]);
err = sys_check_program(dir,filename,&size,&offset);
if((argc==5)||(127<=priority<=-128)&&( err==0)){ //checks for validity
/* if( count == ZERO ){ //If first process allocate queue
rQueue = (ROOT*) sys_alloc_mem(sizeof(ROOT));
wsQueue = (ROOT*) sys_alloc_mem(sizeof(ROOT));
} */
setup_PCB(newPCB,name,APPLICATION,SUSPENDED_READY,priority);
// sets up the adressess
newPCB->memdsc->loadADDR= sys_alloc_mem(size);
newPCB->memdsc->execADDR=newPCB->memdsc->loadADDR + offset;// is this the correct address?
//make sure all registers are properly set
newPCB -> stackdsc-> top = newPCB -> stackdsc-> base + STACKSIZE - sizeof(tcontext);
tempContext = (tcontext *) (newPCB -> stackdsc-> top);
tempContext ->ES = _ES;
tempContext ->DS = _DS;
tempContext ->CS = FP_SEG(newPCB->memdsc->execADDR);
tempContext ->IP = FP_OFF(newPCB->memdsc->execADDR);
tempContext ->FLAGS = 0x200;
// load the program into memory
err = sys_load_program(newPCB->memdsc->loadADDR,size,dir,filename);
insert_PCB(newPCB); // put pcb into a queue
count++;//Update the number of times the function has run.
}
else{
printf("Wrong or invalid arguments entered.");
}
}