Added AMAZING boot menu to KBOOT

boot/stage2/stdio.c

@@ -0,0 +1,141 @@
+#include "stdarg.h"
+#include "stdint.h"
+#include "string.h"
+#include "stdio.h"
+#include "port.h"
+
+static uint32_t xpos;
+static uint32_t ypos;
+static uint8_t attr;
+
+void setAttr(uint8_t newattr) {
+	attr = newattr;
+}
+
+void setCursor(uint32_t row, uint32_t col) {
+	xpos = col;
+	ypos = row;
+	updateCursor();
+}
+
+void updateCursor() {
+	uint16_t pos = xpos + ypos * COLS;
+
+	outb(0x3d4, 0x0f);
+	outb(0x3d5, pos & 0xff);
+	outb(0x3d4, 0x0e);
+	outb(0x3d5, (pos >> 8) & 0xff);
+}
+
+void hideCursor() {
+	outb(0x3d4, 0x0a);
+	outb(0x3d5, 0x20);
+}
+
+void showCursor() {
+	uint8_t start 	= 0;
+	uint8_t end 	= 15;
+
+	outb(0x3d4, 0x0a);
+	outb(0x3d5, (inb(0x3d5) & 0xc0) | start);
+	outb(0x3d4, 0x0b);
+	outb(0x3d5, (inb(0x3d5) & 0xe0) | end);
+}
+
+void cls() {
+	uint8_t* vidmem = (uint8_t*)VIDMEM;
+
+	for (size_t i = 0; i < ROWS * COLS; i++) {
+		vidmem[i * 2] = 0;
+		vidmem[i * 2 + 1] = attr;
+	}
+	
+	xpos = 0;
+	ypos = 0;
+	updateCursor();
+}
+
+void putat(uint32_t row, uint32_t col, int c) {
+	uint8_t* vidmem = (uint8_t*)VIDMEM;
+	vidmem[(col + row * COLS) * 2] = c & 0xFF;
+	vidmem[(col + row * COLS) * 2 + 1] = attr;
+}
+
+void newline() {
+	xpos = 0;
+	ypos++;
+	if (ypos >= ROWS) ypos = 0;
+	updateCursor();
+}
+
+void putc(int c) {
+	putat(ypos, xpos, c);
+	xpos++;
+	if (xpos >= COLS) newline();
+	updateCursor();
+}
+
+void puts(char* s) {
+	while (*s != '\0') {
+		if (*s == '\n' || *s == '\r') {
+			newline();
+			s++;
+		} else putc(*s++);
+	}
+}
+
+int vsnprintf(void* buf, size_t len, char* fmt, va_list args) {
+	char* str = (char*)buf;
+	size_t pos = 0;
+
+	while (*fmt != '\0') {
+		if (*fmt != '%') {
+			if (pos < len - 1) str[pos++] = *fmt++;
+			continue;
+		}
+
+		fmt++;
+		char pad = ' ';
+		int width = 0;
+
+		// TODO: padding
+		if (*fmt == '0') pad = '0';
+		while (*fmt >= '0' && *fmt <= '9') {
+			width *= 10;
+			width += *fmt++ - '0';
+		}
+
+		// DO NOT TALK ABOUT THIS ABOMINATION
+		char* s;
+		switch (*fmt++) {
+		case 'd': s = itoa(va_arg(args, int), 10); goto string;
+		case 'x': s = itoa(va_arg(args, int), 16); goto string;
+		case 's': s = va_arg(args, char*);
+		string: while (*s != '\0' && pos < len - 1) str[pos++] = *s++; break;
+		case 'c': if (pos < len - 1) str[pos++] = va_arg(args, char); break;
+		case '%': if (pos < len - 1) str[pos++] = '%'; break;
+		default:
+			if (pos < len - 1) str[pos++] = '%';
+			if (pos < len - 1) str[pos++] = *(fmt - 1);
+			break;
+		}
+	}
+
+	if (len > 0) {
+		if (pos < len) str[pos++] = '\0';
+		else str[len - 1] = '\0';	// Shouldn't be able to be reached, but who knows
+	}
+
+	return pos;
+}
+
+int printf(char* fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	char buf[256];
+	int ret = vsnprintf(buf, 256, fmt, args);
+	va_end(args);
+	puts(buf);
+	return ret;
+}
+