main.c

// Code originally from https://psp-dev.org/doku.php?id=tutorial:hello_world
#include <pspkernel.h>
#include <pspdebug.h>

PSP_MODULE_INFO("Tutorial", 0, 1, 0);

int exit_callback(int arg1, int arg2, void* common){
	sceKernelExitGame();
	return 0;
}

int CallbackThread(SceSize args, void* argp) {
	int cbid = sceKernelCreateCallback("Exit Callback", exit_callback, NULL);
	sceKernelRegisterExitCallback(cbid);
	sceKernelSleepThreadCB();

	return 0;
}

int SetupCallbacks(void) {
	int thid = sceKernelCreateThread("update_thread", CallbackThread, 0x11, 0xFA0, 0, 0);
	if (thid >= 0) {
		sceKernelStartThread(thid, 0, 0);
	}
	return thid;
}

void hello(void){

    pspDebugScreenPrintf("\n\nHello there!");
}

int main() { //In C++ `auto main() -> int` is also valid.
	SetupCallbacks();
	pspDebugScreenInit();
	hello();
	return 0;
}