.global loader

.set ALIGN,    1<<0
.set MEMINFO,  1<<1
.set FLAGS,    ALIGN | MEMINFO
.set MAGIC,    0x1BADB002
.set CHECKSUM, -(MAGIC + FLAGS)

.align 4
.long MAGIC
.long FLAGS
.long CHECKSUM

.set SIZE, 0x4000
.comm stack, SIZE, 32

loader:
   mov   $(stack + SIZE), %esp
   push  %eax
   push  %ebx

   call  k_main

   cli
hang:
   hlt
   jmp   hang

#define BLACK     0
#define BLUE      1
#define GREEN     2
#define CYAN      3
#define RED       4
#define MAGENTA   5
#define BROWN     6
#define L_GREY    7
#define D_ GREY   8
#define L_BLUE    9
#define L_GREEN   10
#define L_CYAN    11
#define L_RED     12
#define L_MAGENTA 13
#define L_BROWN   14
#define WHITE     15

int color(char background, char foreground)
{
        return (background << 4) | foreground;
}

int line_break(unsigned int line, unsigned int i, char *message)
{
        unsigned int count = 0;
        while(*++message != ' ' && *message != '\0')
        {
                count++;
        }
        if((count << 1) + i >= (++line*160))
        {
                return 1;
        }
        return 0;
}

void clear_screen()
{
        short *vidmem = (short *) 0xb8000;
        unsigned int i = 0;
        while( i < 2000)
        {
                vidmem[i++]=0;
        }
}

unsigned int print(char *message, unsigned int line, int color)
{
        char *vidmem = (char *) 0xb8000;
        unsigned int i = (line*160);
        for(;*message != '\0'; *message++)
        {
                if(*message=='\n' || (*message == ' ' && line_break(line, i, message)))
                {
                        i=(++line*160);
                }
                else
                {
                        vidmem[i++]=*message;
                        vidmem[i++]= color;
                }
        }

        return 1;
}

void k_main( void* mbd, unsigned int magic )
{
        clear_screen();
        print("Hello World", 0, color(BLACK, L_GREY));