My os

kmain.c

#define VGA_SCR_WIDTH 80
#define VGA_SCR_HEIGHT 25
short* VGA_PTR = (short*)0xb8000;


void printvmem(const char* str, char color, short offset)
{
    int i = 0;
	while(str[i] != 0)
    {
        VGA_PTR[i+offset] = (color << 8) | str[i];
        ++i;
    }
}

// TODO: CHANGE THIS
void cleanscr(char color)
{
    printvmem("                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                ", color, 0);
}

void sleep(short millis)
{
    for (int i = 0; i < millis * 100000; ++i) {}
}

extern void kmain()
{
    const short str_l = 39;
    short offset = 0;
	const char* hello = "WELCOME TO ISHIDEX2'S OPERATING SYSTEM!";
    while (1) 
    {
        cleanscr(0x33);
        printvmem(hello, 0x12, offset);
        if (offset > (2000-str_l))
        {
            offset = 0;
        }
        offset += 1;
        sleep(100);
    }
}