Move terminal functions to library

src/kern.c

@@ -2,7 +2,6 @@
 #include <stdbool.h> /* C doesn't have booleans by default. */
 #endif
 #include <stddef.h>
-#include <stdint.h>
 
 /* Check if the compiler thinks we are targeting the wrong operating system. */
 #if defined(__linux__)
@@ -15,102 +14,20 @@
 #endif
 
 #include "serial.h"
-
-/* Hardware text mode color constants. */
-enum vga_color {
-	COLOR_BLACK = 0,
-	COLOR_BLUE = 1,
-	COLOR_GREEN = 2,
-	COLOR_CYAN = 3,
-	COLOR_RED = 4,
-	COLOR_MAGENTA = 5,
-	COLOR_BROWN = 6,
-	COLOR_LIGHT_GREY = 7,
-	COLOR_DARK_GREY = 8,
-	COLOR_LIGHT_BLUE = 9,
-	COLOR_LIGHT_GREEN = 10,
-	COLOR_LIGHT_CYAN = 11,
-	COLOR_LIGHT_RED = 12,
-	COLOR_LIGHT_MAGENTA = 13,
-	COLOR_LIGHT_BROWN = 14,
-	COLOR_WHITE = 15,
-};
-
-uint8_t make_color(enum vga_color fg, enum vga_color bg) {
-	return fg | bg << 4;
-}
-
-uint16_t make_vgaentry(char c, uint8_t color) {
-	uint16_t c16 = c;
-	uint16_t color16 = color;
-	return c16 | color16 << 8;
-}
-
-size_t strlen(const char* str) {
-	size_t ret = 0;
-	while ( str[ret] != 0 )
-		ret++;
-	return ret;
-}
-
-static const size_t VGA_WIDTH = 80;
-static const size_t VGA_HEIGHT = 25;
-
-size_t terminal_row;
-size_t terminal_column;
-uint8_t terminal_color;
-uint16_t* terminal_buffer;
-
-void terminal_initialize() {
-	terminal_row = 0;
-	terminal_column = 0;
-	terminal_color = make_color(COLOR_LIGHT_GREY, COLOR_BLACK);
-	terminal_buffer = (uint16_t*) 0xB8000;
-	for (size_t y = 0; y < VGA_HEIGHT; y++) {
-		for (size_t x = 0; x < VGA_WIDTH; x++) {
-			const size_t index = y * VGA_WIDTH + x;
-			terminal_buffer[index] = make_vgaentry(' ', terminal_color);
-		}
-	}
-}
-
-void terminal_setcolor(uint8_t color) {
-	terminal_color = color;
-}
-
-void terminal_putentryat(char c, uint8_t color, size_t x, size_t y) {
-	const size_t index = y * VGA_WIDTH + x;
-	terminal_buffer[index] = make_vgaentry(c, color);
-}
-
-void terminal_putchar(char c) {
-	terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
-	if (++terminal_column == VGA_WIDTH) {
-		terminal_column = 0;
-		if (++terminal_row == VGA_HEIGHT) {
-			terminal_row = 0;
-		}
-	}
-}
-
-void terminal_writestring(const char* data) {
-	size_t datalen = strlen(data);
-	for (size_t i = 0; i < datalen; i++)
-		terminal_putchar(data[i]);
-}
+#include "term.h"
 
 #if defined(__cplusplus)
 extern "C" /* Use C linkage for kernel_main. */
 #endif
 void kernel_main() {
-	/* Initialize terminal interface */
+	/* Initialize terminal and serial interfaces */
 	terminal_initialize();
+    serial_init();
 
 	/* Since there is no support for newlines in terminal_putchar
          * yet, '\n' will produce some VGA specific character instead.
          * This is normal.
          */
-    serial_init();
     serial_writestring("First Serial Test!\n");
     terminal_writestring("Hello, kernel World!\n");
     serial_writestring("Second Serial Test\n");

src/term.c

+/*
+  term.c contains functions for working with/writing to the terminal
+
+  It was taken from the simple kernel from the osdev wiki
+*/
+
+#include "term.h"
+
+uint8_t make_color(enum vga_color fg, enum vga_color bg) {
+	return fg | bg << 4;
+}
+
+uint16_t make_vgaentry(char c, uint8_t color) {
+	uint16_t c16 = c;
+	uint16_t color16 = color;
+	return c16 | color16 << 8;
+}
+
+size_t strlen(const char* str) {
+	size_t ret = 0;
+	while ( str[ret] != 0 )
+		ret++;
+	return ret;
+}
+
+static const size_t VGA_WIDTH = 80;
+static const size_t VGA_HEIGHT = 25;
+
+size_t terminal_row;
+size_t terminal_column;
+uint8_t terminal_color;
+uint16_t* terminal_buffer;
+
+void terminal_initialize() {
+	terminal_row = 0;
+	terminal_column = 0;
+	terminal_color = make_color(COLOR_LIGHT_GREY, COLOR_BLACK);
+	terminal_buffer = (uint16_t*) 0xB8000;
+	for (size_t y = 0; y < VGA_HEIGHT; y++) {
+		for (size_t x = 0; x < VGA_WIDTH; x++) {
+			const size_t index = y * VGA_WIDTH + x;
+			terminal_buffer[index] = make_vgaentry(' ', terminal_color);
+		}
+	}
+}
+
+void terminal_setcolor(uint8_t color) {
+	terminal_color = color;
+}
+
+void terminal_putentryat(char c, uint8_t color, size_t x, size_t y) {
+	const size_t index = y * VGA_WIDTH + x;
+	terminal_buffer[index] = make_vgaentry(c, color);
+}
+
+void terminal_putchar(char c) {
+	terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
+	if (++terminal_column == VGA_WIDTH) {
+		terminal_column = 0;
+		if (++terminal_row == VGA_HEIGHT) {
+			terminal_row = 0;
+		}
+	}
+}
+
+void terminal_writestring(const char* data) {
+	size_t datalen = strlen(data);
+	for (size_t i = 0; i < datalen; i++)
+		terminal_putchar(data[i]);
+}

src/term.h

+/*
+  term.h contains headers and definitions for terminal handling
+*/
+
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+/* Hardware text mode color constants. */
+enum vga_color {
+	COLOR_BLACK = 0,
+	COLOR_BLUE = 1,
+	COLOR_GREEN = 2,
+	COLOR_CYAN = 3,
+	COLOR_RED = 4,
+	COLOR_MAGENTA = 5,
+	COLOR_BROWN = 6,
+	COLOR_LIGHT_GREY = 7,
+	COLOR_DARK_GREY = 8,
+	COLOR_LIGHT_BLUE = 9,
+	COLOR_LIGHT_GREEN = 10,
+	COLOR_LIGHT_CYAN = 11,
+	COLOR_LIGHT_RED = 12,
+	COLOR_LIGHT_MAGENTA = 13,
+	COLOR_LIGHT_BROWN = 14,
+	COLOR_WHITE = 15,
+};
+
+uint8_t make_color(enum vga_color fg, enum vga_color bg);
+uint16_t make_vgaentry(char c, uint8_t color);
+size_t strlen(const char* str);
+
+void terminal_initialize();
+void terminal_setcolor(uint8_t color);
+void terminal_putentryat(char c, uint8_t color, size_t x, size_t y);
+void terminal_putchar(char c);
+void terminal_writestring(const char* data);