int step(s_emu *emu) {
emu->display_changed = 0;
if (execute_opcode(emu, get_opcode(emu)) < 0)
return -1;
emu->MC += 2;
if (emu->delay_timer > 0) emu->delay_timer -= 1;
if (emu->sound_timer > 0) emu->sound_timer -= 1;
}
void execute_loop(chip_8_cpu cpu, FILE *debug_log) {
if (pthread_create(&(cpu->delay_decrement_thread), NULL, delay_thread, cpu) != 0) {
shutdown_cpu(cpu, 1);
}
if (pthread_create(&(cpu->sound_decrement_thread), NULL, sound_thread, cpu) != 0) {
fprintf(stderr, "Failed to start the sound register thread, exiting...\n");
shutdown_cpu(cpu, 1);
}
pthread_detach(cpu->delay_decrement_thread);
pthread_detach(cpu->sound_decrement_thread);
cpu->chip_8_screen = init_ncurses(default_window_height, default_window_width);
refresh_window(cpu->chip_8_screen);
while (1) {
if (cpu->program_counter >= MEMORY_SIZE) {
fprintf(stderr, "ERR - Fatal memory error: invalid access at memory cell: '%d'\n", cpu->program_counter);
shutdown_cpu(cpu, 1);
}
if (cpu->halt) {
break;
}
opcode instr = fetch_opcode(cpu);
if (debug_log) {
print_debug_info(debug_log, instr, cpu);
}
execute_opcode(instr, cpu);
if (cpu->performed_jump) {
cpu->performed_jump = false;
continue;
}
if (cpu->skip_opcode) {
cpu->program_counter = cpu->program_counter + 2;
cpu->skip_opcode = false;
}
else {
cpu->program_counter = cpu->program_counter + 1;
}
}
// allow 0.1 seconds for the threads to clean up their memory
usleep(100000);
delwin(cpu->chip_8_screen);
endwin();
}
int main(int argc, const char * argv[]) {
// use current time to generate random numbers, in order to be more "random"
srand((unsigned)time(NULL));
// make call to filereader to create all semaphores
initialize_semaphores();
// make call to filereader to open all files and initialize process blocks
initialize_processes();
// set active process to first one in the linked list
active_process = ready_queue;
// execute all code read in from source
while (active_process->PC <= active_process->program_lines) {
// if process has reached time slice, reset to zero, move to end of RQ, and start next process
if(active_process->IC == active_process->time_slice) {
switch_processes();
}
// copy current line into the instruction register (IR)
memory_address = get_memory_address(active_process, active_process->PC);
for (k = 0; k < 6; k++) {
IR[k] = memory[memory_address][k];
}
//printf("PC within main: %d\n", active_process->PC);
//printf("memory address within main: %d\n", memory_address);
// calculate integer equivalent of opcode chars
opcode = (int) (IR[0] - 48) * 10;
opcode += (int) (IR[1] - 48);
printf("opcode is: %d\n", opcode);
// make call to api to execute relevant function for opcode
execute_opcode(opcode);
if(!external_switch) {
active_process->IC++;
active_process->PC++;
}
// reset flag
external_switch = 0;
}
}
