#include <stdint.h>

int _syscall(int, int, int, int);

int main() {
	uint8_t color = _syscall(1, 2, 3, 4);

	// change the colors of VGA text
	// doesn't require a lot of code, but still shows that it's working
	uint8_t *vga = (void*) 0xB8000;
	for (int i = 0; i < 80 * 25; i++)
		vga[(i << 1) + 1] = color;

	// try to mess with kernel memory
	uint8_t *kernel = (void*) 0x100000;
	*kernel = 0; // should segfault
}