feature: scrolling (and memcpy added)

headers/string.h

@@ -7,3 +7,4 @@ int strcmp(const char *s1, const char *s2);
 int strncmp(const char *s1, const char *s2, size_t n);
 size_t strlen(const char *str);
 char *strstr(const char *haystack, const char *needle);
+void *memcpy(void *dest, const void *src, size_t n);

src/string/memcpy.c

@@ -0,0 +1,14 @@
+#include "kprintf.h"
+#include <stddef.h>
+#include <stdint.h>
+
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	uint16_t *c1 = (uint16_t *)dest;
+	const uint16_t *c2 = (const uint16_t *)src;
+
+	for (size_t i = 0; i < n; i++)
+		c1[i] = c2[i];
+	kprintf(0, "c1: %s\n", c1);
+	return c1;
+}

src/terminal/put.c

@@ -1,6 +1,7 @@
 #include "terminal.h"
-#include "string.h"
 #include "ctype.h"
+#include "kprintf.h"
+#include "string.h"
 
 #include <stdbool.h>
 #include <stddef.h>
@@ -13,7 +14,7 @@ static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg)
 
 static inline uint16_t vga_entry(unsigned char uc, uint8_t color)
 {
-	return (uint16_t) uc | (uint16_t) color << 8;
+	return (uint16_t)uc | (uint16_t)color << 8;
 }
 
 #define VGA_WIDTH 80
@@ -22,14 +23,13 @@ static inline uint16_t vga_entry(unsigned char uc, uint8_t color)
 size_t terminal_row;
 size_t terminal_column;
 uint8_t terminal_color;
-uint16_t* terminal_buffer;
+uint16_t *terminal_buffer;
-
 void terminal_initialize(void)
 {
 	terminal_row = 0;
 	terminal_column = 0;
 	terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
-	terminal_buffer = (uint16_t*) 0xB8000;
+	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;
@@ -49,34 +49,45 @@ void terminal_putentryat(char c, uint8_t color, size_t x, size_t y)
 	terminal_buffer[index] = vga_entry(c, color);
 }
 
+static void terminal_scroll(void)
+{
+	terminal_row--;
+	for (size_t i = 0; i < VGA_WIDTH * (VGA_HEIGHT - 1); i++)
+		terminal_buffer[i] = terminal_buffer[i + VGA_WIDTH];
+	for (size_t i = 0; i < VGA_WIDTH; i++)
+		terminal_putentryat(' ', terminal_color, i, VGA_HEIGHT - 1);
+}
+
+static void terminal_new_line(void)
+{
+	terminal_column = 0;
+	if (++terminal_row == VGA_HEIGHT)
+		terminal_scroll();
+}
+
 int terminal_putchar(char c)
 {
 	if (c == '\r')
 		terminal_column = 0;
-	else if (c == '\n') {
+	else if (c == '\n')
-		terminal_column = 0;
+		terminal_new_line();
-		terminal_row++;
-	}
 	if (!isprint(c))
 		return 1;
 	terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
-	if (++terminal_column == VGA_WIDTH) {
+	if (++terminal_column == VGA_WIDTH)
-		terminal_column = 0;
+		terminal_new_line();
-		if (++terminal_row == VGA_HEIGHT)
-			terminal_row = 0;
-	}
 	return 1;
 }
 
-int terminal_write(const char* data, size_t size) 
+int terminal_write(const char *data, size_t size)
 {
 	size_t i;
 	for (i = 0; i < size; i++)
 		terminal_putchar(data[i]);
-    return (int) i;
+	return (int)i;
 }
 
-int terminal_writestring(const char* data) 
+int terminal_writestring(const char *data)
 {
 	size_t len = strlen(data);
 	terminal_write(data, len);