boot: Clean up editor redraw, shift-arrow input?

boot/editor.c

@@ -6,26 +6,42 @@
 
 int boot_edit = 0;
 
+static uint16_t attribute_cache[80*25] = {0};
+
+static void draw_text(int cursor, int len) {
+	int i = 0;
+	for (int _my_y = 0; _my_y < 25; ++_my_y) {
+		for (int _my_x = 0; _my_x < 80; ++_my_x) {
+			int ch = (i < len) ? cmdline[i] : ' ';
+			int attr = (i == cursor) ? 0x70 : 0x07;
+			uint16_t combined = (attr << 8) | (ch & 0xFF);
+
+			if (attribute_cache[i] != combined) {
+				move_cursor(_my_x, _my_y);
+				set_attr(attr);
+				print_((char[]){ch,'\0'});
+				attribute_cache[i] = combined;
+			}
+
+			i++;
+		}
+	}
+}
+
 int boot_editor(void) {
 	int len    = strlen(cmdline);
 	int cursor = len;
+	int data = 0;
+
+	memset(attribute_cache, 0, sizeof(attribute_cache));
 
 	while (1) {
-		move_cursor(0,0);
-		for (int i = 0; i <= len; ++i) {
-			set_attr(i == cursor ? 0x70 : 0x07);
-			print_((char[]){cmdline[i],'\0'});
-		}
-		print_(" ");
-		set_attr(0x07);
-		do {
-			do {
-				print_(" ");
-			} while (x);
-		} while (y);
+		draw_text(cursor, len);
 
-		char data = 0;
-		int status = read_key(&data);
+		int status;
+		do {
+			status = read_key(&data);
+		} while (status == 1);
 
 		if (status == 0) {
 			/* Handle a few special characters */

boot/kbd.c

@@ -58,7 +58,7 @@ int read_scancode(int timeout) {
 	}
 }
 
-int read_key(char * c) {
+int read_key(int * c) {
 	EFI_INPUT_KEY Key;
 	unsigned long int index;
 	uefi_call_wrapper(ST->BootServices->WaitForEvent, 3, 1, &ST->ConIn->WaitForKey, &index);
@@ -106,11 +106,28 @@ static char kbd_us_l2[128] = {
 	'-', 0, 0, 0, '+', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 };
 
-int read_key(char * c) {
+int read_key(int * c) {
 	static int shift_state = 0;
 
 	int sc = read_scancode(0);
 
+	if (sc == 0xe0) {
+		*c = 0xe0;
+		return 1;
+	}
+
+	if (*c == 0xe0) {
+		*c = 0;
+		switch (sc) {
+			/* Keft left and right */
+			case 0x4B:
+				return shift_state ? 4 : 2;
+			case 0x4D:
+				return shift_state ? 5 : 3;
+		}
+		return 1;
+	}
+
 	switch (sc) {
 		/* Shift down */
 		case 0x2A:
@@ -122,10 +139,6 @@ int read_key(char * c) {
 		case 0xB6:
 			shift_state = 0;
 			return 1;
-
-		/* Keft left and right */
-		case 0x4B: return shift_state ? 4 : 2;
-		case 0x4D: return shift_state ? 5 : 3;
 	}
 
 	if (!(sc & 0x80)) {
@@ -146,10 +159,6 @@ int read_scancode(int timeout) {
 	} else {
 		while (!(inportb(0x64) & 1));
 	}
-	int out;
-	while (inportb(0x64) & 1) {
-		out = inportb(0x60);
-	}
-	return out;
+	return inportb(0x60);
 }
 #endif

boot/kbd.h

@@ -9,5 +9,5 @@
 #define KBD_SCAN_9     10
 
 int read_scancode(int);
-int read_key(char * c);
+int read_key(int * c);