kernel.cpp

#include "types.h"
#include "gdt.h"
#include "interrupts.h"
#include "keyboard.h"

void printf(char* str)
{
    static uint16_t* video_memory = (uint16_t*)0xb8000;

    static uint8_t x = 0, y = 0;

    for(int i=0; str[i] != '\0'; ++i)
    {
        switch(str[i])
        {   
            case  '\n':
                y++;
                x = 0;
                break;
            default:
                video_memory[80*y+x] = (video_memory[80*y+x] & 0xFF00) | str[i];
                x++;
                break;
        }

        
        if(x>=80)
        {
            y++;
            x = 0;
        }

        if(y >= 25)
        {
            for(y = 0; y < 25; y++)
                for(x = 0; x < 80; x++)
                    video_memory[80*y+x] = (video_memory[80*y+x] & 0xFF00) | ' ';
            x = 0; y = 0;
        }
    }
}

typedef void (*constructor)();
extern "C" constructor start_ctors;
extern "C" constructor end_ctors;
extern "C" void callConstructors()
{
    for(constructor* i = &start_ctors; i != &end_ctors; i++)
        (*i)();
}

extern "C" void kernelMain(void* multiboot_structure,  uint32_t magicnumber)
{
    printf("Hello Wilson!\n");
    printf("Hello XSW!");

    GlobalDescriptorTable gdt;
    InterruptManager interrupts(&gdt);

    KeyboardDriver keyboard(&interrupts);

    interrupts.Activate();

    while(1);
}