cppOS/utils.cpp at master · justingarfield/cppOS · GitHub

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#include "architecture/types.h"

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

	static uint8_t x = 0, y = 0;

	// Screen is 80 characters x 25 lines
	for(int i = 0; str[i] != '\0'; i++) {

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

			x = 0;
			y = 0;
		}

	}

}

void clearScreen() {

	for (int i = 0; i < 25; i++)
		printf("\n");

}