#include "gdt.hpp"
#include "idt.hpp"
#include "memory.hpp"
#include "multiboot.hpp"
#include "pic.hpp"
#include "pit.hpp"
#include "tasking.hpp"
#include "vgaterminal.hpp"

static VGATerminal vga;
TextOutput& term = vga;

static volatile bool termBusy = false;

void kernel_main(void) 
{
    term.write("Clyne's kernel, v2024\n\n");

    if (!multiboot_initialize())
        for (;;);

    idt_register_callback(14, [](const Registers& regs) {
        term.write("Page fault! eip=");
        term.write(regs.eip);
        term.write('\n');
        for (;;);
    });

    memory_initialize();
    gdt_initialize();
    pic_initialize();
    idt_initialize();
    pit_initialize(100);
    asm volatile("sti");
    tasking_initialize();
    term.write("Tasking enabled.\n");

    tasking_spawn([] {
        for (;;) {
            do pit_busy_wait(1);
            while (termBusy);

            termBusy = true;
            term.write('B');
            termBusy = false;
        }
    }, 256);

    tasking_spawn([] {
        for (;;) {
            do pit_busy_wait(1);
            while (termBusy);

            termBusy = true;
            term.write('C');
            termBusy = false;
        }
    }, 256);

    for (;;) {
        do pit_busy_wait(1);
        while (termBusy);

        termBusy = true;
        term.write('A');
        termBusy = false;
    }
}

extern "C"
void memmove(char* dst, char* src, size_t sz) {
    while (sz) {
        *dst = *src;
        ++dst;
        ++src;
        --sz;
    }
}