From 766fc0f052c2050b13fee6b39e79d82b8a3b8988 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Sun, 23 Jan 2022 16:27:08 +0200
Subject: [PATCH] Add keyboard testing

---
 kernel.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 134 insertions(+), 1 deletion(-)

diff --git a/kernel.c b/kernel.c
index f0ddbe3..b756085 100644
--- a/kernel.c
+++ b/kernel.c
@@ -1,3 +1,4 @@
+//#define PORT_DEBUG
 /* Based on Bare Bones tutorial on OSDev wiki */
 
 #include <stdbool.h>
@@ -112,9 +113,24 @@ void terminal_writestring(const char* data)
 	terminal_write(data, strlen(data));
 }
 
+const char hex[] = "0123456789abcdef";
+
+void terminal_writehex(uint8_t byte) {
+	terminal_putchar(hex[byte >> 4]);
+	terminal_putchar(hex[byte & 0xf]);
+}
+
 // (out|in)port from sortix, Copyright (c) 2014, 2015 Jonas 'Sortie' Termansen.
 void outport8(uint16_t port, uint8_t value)
 {
+#ifdef PORT_DEBUG
+	terminal_writestring("<out ");
+	terminal_writehex(port >> 8);
+	terminal_writehex(port);
+	terminal_writestring(" ");
+	terminal_writehex(value);
+	terminal_writestring(">");
+#endif
 	asm volatile ("outb %1, %0" : : "dN" (port), "a" (value));
 }
 
@@ -122,6 +138,14 @@ uint8_t inport8(uint16_t port)
 {
 	uint8_t result;
 	asm volatile("inb %1, %0" : "=a" (result) : "dN" (port));
+#ifdef PORT_DEBUG
+	terminal_writestring("<in ");
+	terminal_writehex(port >> 8);
+	terminal_writehex(port);
+	terminal_writestring(" ");
+	terminal_writehex(result);
+	terminal_writestring(">");
+#endif
 	return result;
 }
 
@@ -232,13 +256,122 @@ void disable_translation(void) {
 	write_config_8042(config);
 }
 
+uint8_t read_keyboard(void) {
+	while (!(status_8042() & (1<<0)));
+	return read_8042();
+}
+
+void enable_scanning(void) {
+	write_8042(0xf4);
+	if (read_keyboard() != 0xfa)
+		terminal_writestring("Enabling scanning failed\n");
+	while (status_8042() & (1<<0))
+		(void) read_8042();
+}
+
+void disable_scanning(void) {
+	write_8042(0xf5);
+	if (read_keyboard() != 0xfa)
+		terminal_writestring("Disabling scanning failed\n");
+	while (status_8042() & (1<<0))
+		(void) read_8042();
+}
+
+void set_scancode_set(uint8_t set) {
+	write_8042(0xf0);
+	write_8042(set);
+	if (read_keyboard() != 0xfa)
+		terminal_writestring("Setting scancode set failed\n");
+	while (status_8042() & (1<<0))
+		(void) read_8042();
+}
+
+uint8_t get_scancode_set(void) {
+	write_8042(0xf0);
+	write_8042(0);
+	if (read_keyboard() != 0xfa)
+		terminal_writestring("Getting scancode set failed\n");
+	uint8_t set;
+	while ( (set = read_keyboard()) == 0xfa );
+	return set;
+}
+
+#define KEY_A_SET1 0x1e
+#define KEY_A_SET2 0x1c
+#define KEY_A_MISINTERPRET 0x03
+
+void print_key(uint8_t code) {
+	switch (code) {
+		case KEY_A_SET1: terminal_writestring("Set 1 A"); break;
+		case KEY_A_SET2: terminal_writestring("Set 2 A"); break;
+		case KEY_A_MISINTERPRET: terminal_writestring("Set 1 A misinterpreted as set 2 A"); break;
+		default:
+			terminal_writestring("Unknown byte ");
+			terminal_writehex(code);
+			break;
+	}
+}
+
+void key_prompt(uint8_t expect) {
+	enable_scanning();
+	terminal_writestring("Press A... ");
+	uint8_t code = read_keyboard();
+	if ( code == expect )
+		terminal_setcolor(vga_entry_color(VGA_COLOR_GREEN, VGA_COLOR_BLACK));
+	else
+		terminal_setcolor(vga_entry_color(VGA_COLOR_RED, VGA_COLOR_BLACK));
+	print_key(code);
+	if ( code == expect )
+		terminal_writestring("\n");
+	else
+		terminal_writestring("(!)\n");
+	terminal_setcolor(vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK));
+	read_keyboard(); // Key up
+	disable_scanning();
+}
+
 void kernel_main(void)
 {
 	/* Initialize terminal interface */
 	terminal_initialize();
 
 	init_8042();
-	if (single_channel)
+	terminal_writestring("Assuming keyboard is channel 1\n");
+
+	terminal_writestring("\nTranslation initially ");
+	if (translation_initially)
+		terminal_writestring("on\n");
+	else
+		terminal_writestring("off\n");
+	key_prompt(translation_initially ? KEY_A_SET1 : KEY_A_SET2);
+
+	disable_translation();
+	terminal_writestring("\nTranslation off, scancode set initially ");
+	uint8_t initial_scancode = get_scancode_set();
+	terminal_writehex(initial_scancode);
+	terminal_writestring("\n");
+	key_prompt(initial_scancode == 1 ? KEY_A_SET1 : KEY_A_SET2);
+
+	set_scancode_set(1);
+	terminal_writestring("Translation off, trying set 1... scancode set set to ");
+	terminal_writehex(get_scancode_set());
+	terminal_writestring("\n");
+	key_prompt(KEY_A_SET1);
+
+	set_scancode_set(2);
+	terminal_writestring("Translation off, trying set 2... scancode set set to ");
+	terminal_writehex(get_scancode_set());
+	terminal_writestring("\n");
+	key_prompt(KEY_A_SET2);
+
+	set_scancode_set(1);
+	enable_translation();
+	terminal_writestring("\nTranslation on, trying set 1\n");
+	key_prompt(KEY_A_MISINTERPRET);
+
+	set_scancode_set(2);
+	terminal_writestring("Translation on, trying set 2\n");
+	key_prompt(KEY_A_SET1);
 
 	terminal_writestring("\nHanging\n");
 }