From df9d4e1a269721b30c02a2ce789bc6dd732793d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Sun, 23 Jan 2022 17:28:30 +0200
Subject: [PATCH] Get working on real HW and expand diagnostics

---
 grub.cfg |  2 ++
 kernel.c | 53 ++++++++++++++++++++++++++++++++++++-----------------
 2 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/grub.cfg b/grub.cfg
index 94cd89a..b250464 100644
--- a/grub.cfg
+++ b/grub.cfg
@@ -1,3 +1,5 @@
+set timeout=2
+
 menuentry "ps2 kbtest" {
 	multiboot /boot/ps2-kbtest.kernel
 }
diff --git a/kernel.c b/kernel.c
index a978d4c..3c4e690 100644
--- a/kernel.c
+++ b/kernel.c
@@ -178,14 +178,18 @@ void write_config_8042(uint8_t config) {
 	write_8042(config);
 }
 
+void flush_buffer() {
+	while (status_8042() & (1<<0))
+		(void) read_8042();
+}
+
 void init_8042(void) {
 	// Disable devices
 	command_8042(0xad);
 	command_8042(0xa7);
 
 	// Flush output buffer
-	while (status_8042() & (1<<0))
-		(void) read_8042();
+	flush_buffer();
 	
 	// Read configuration
 	uint8_t config = read_config_8042();
@@ -262,37 +266,36 @@ uint8_t read_keyboard(void) {
 }
 
 void enable_scanning(void) {
+	flush_buffer();
 	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) {
+	flush_buffer();
 	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) {
+	flush_buffer();
 	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();
+	flush_buffer();
 }
 
 uint8_t get_scancode_set(void) {
+	flush_buffer();
 	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 );
+	while ((set = read_keyboard()) == 0xfa);
 	return set;
 }
 
@@ -315,6 +318,7 @@ void print_key(uint8_t code) {
 void key_prompt(uint8_t expect) {
 	enable_scanning();
 	terminal_writestring("Press A... ");
+	flush_buffer();
 	uint8_t code = read_keyboard();
 	if ( code == expect )
 		terminal_setcolor(vga_entry_color(VGA_COLOR_GREEN, VGA_COLOR_BLACK));
@@ -338,39 +342,54 @@ void kernel_main(void)
 	init_8042();
 	terminal_writestring("Assuming keyboard is channel 1\n");
 
+	terminal_setcolor(vga_entry_color(VGA_COLOR_BROWN, VGA_COLOR_BLACK));
+	terminal_writestring("\nNOTE: ");
+	terminal_setcolor(vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK));
+	terminal_writestring("If getting scancode set seems to hang, tap the 'A' key.\n");
+
 	terminal_writestring("\nTranslation initially ");
 	if (translation_initially)
-		terminal_writestring("on\n");
+		terminal_writestring("on, scancode set initially set to... ");
 	else
-		terminal_writestring("off\n");
+		terminal_writestring("off, scancode set initially set to... ");
+	terminal_writehex(get_scancode_set());
+	terminal_writestring("\n");
 	key_prompt(translation_initially ? KEY_A_SET1 : KEY_A_SET2);
 
 	disable_translation();
-	terminal_writestring("\nTranslation off, scancode set initially ");
+	terminal_writestring("\nTranslation off, scancode set initially set to... ");
 	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);
 
+	terminal_writestring("Translation off, trying set 1... ");
 	set_scancode_set(1);
-	terminal_writestring("Translation off, trying set 1... scancode set set to ");
+	terminal_writestring("scancode set set to... ");
 	terminal_writehex(get_scancode_set());
 	terminal_writestring("\n");
 	key_prompt(KEY_A_SET1);
 
+	terminal_writestring("Translation off, trying set 2... ");
 	set_scancode_set(2);
-	terminal_writestring("Translation off, trying set 2... scancode set set to ");
+	terminal_writestring("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");
+	terminal_writestring("\nTranslation on, trying set 1... ");
+	set_scancode_set(1);
+	terminal_writestring("scancode set set to... ");
+	terminal_writehex(get_scancode_set());
+	terminal_writestring("\n");
 	key_prompt(KEY_A_MISINTERPRET);
 
+	terminal_writestring("Translation on, trying set 2... ");
 	set_scancode_set(2);
-	terminal_writestring("Translation on, trying set 2\n");
+	terminal_writestring("scancode set set to... ");
+	terminal_writehex(get_scancode_set());
+	terminal_writestring("\n");
 	key_prompt(KEY_A_SET1);
 
 	terminal_writestring("\nHanging\n");