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#include "k_defines.h"

inline void outportb(unsigned int port, unsigned char value);

unsigned int panic(char *message);
void k_main();

void k_clear_screen();
unsigned int k_printf(char *message, unsigned int line);
void update_cursor(int row, int col);

void k_main()
{
	k_clear_screen();

	k_printf("Starting P-DOS...",0);
	update_cursor(1,0);
	k_printf("Nopony else is in here. Looks like I'm forever aLUNA. (How punny of me *induberdebly*)",3);
	update_cursor(5,0);
};

unsigned int k_printf(char *message, unsigned int line)
{
	char *vram = (char *) 0xb8000;
	unsigned int i=0;

	i=(line*80*2);

	while(*message!=0)
	{
		if(*message==0x2f)
		{
			*message++;
			if(*message==0x63)
			{
				line++;
				i=(line*80*2);
				*message++;
				if(*message==0)
				{
					return(1);
				};
			};
		};
		vram[i]=*message;
		*message++;
		i++;
		vram[i]=0x07;
		i++;
	};

	return(1);
};

void k_clear_screen()
{
	char *vram = (char *) 0xb8000;
	unsigned int i=0;
	while(i<(80*2*25))
	{
		vram[i]=' ';
		i++;
		vram[i]=WHITE_TXT;
		i++;
	};
};

inline void outportb(unsigned int port, unsigned char value)
{
	asm volatile ("outb %%al, %%dx"::"d" (port), "a" (value));
};

void update_cursor(int row, int col)
{
	USHORT position=(row*80)+col;

	outportb(0x3d4, 0x0f);
	outportb(0x3d5, (UCHAR)(position&0xff));

	outportb(0x3d4, 0x0e);
	outportb(0x3d5, (UCHAR)((position<<8)&0xff));
};

unsigned int panic(char *message)
{
	char *vram = (char *) 0xb8000;
	unsigned int i=0;
	unsigned int line=0;

	i=(line*80*2);

	while(*message!=0)
	{
		if(*message==0x2f)
		{
			*message++;
			if(*message==0x63)
			{
				line++;
				i=(line*80*2);
				*message++;
				if(*message==0)
				{
					return(1);
				};
			};
		};
		vram[i]=*message;
		*message++;
		i++;
		vram[i]=0x9; //use blue text
		i++;
	};

	return(1);
};

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#define WHITE_TXT 0x7
#define BLUE_TXT 0x09

#define UCHAR unsigned char
#define USHORT unsigned short

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OUTPUT_FORMAT("binary")
ENTRY(k_main)
SECTIONS
{
  .text  0x005000 : {
    code = .; _code = .; __code = .;
    *(.text)
    . = ALIGN(4096);
  }
  .data  : {
    data = .; _data = .; __data = .;
    *(.data)
    . = ALIGN(4096);
  }
  .bss  :
  {
    bss = .; _bss = .; __bss = .;
    *(.bss)
    . = ALIGN(4096);
  }
  end = .; _end = .; __end = .;
}

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echo off
gcc-3 -c pony.cpp -o pony.o
ld -T kernel.ld -o PONY.SYS pony.o
copy PONY.SYS A:\PONY.SYS

pause

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ld: cannot perform PE operation on a non PE file 'PONY.SYS'