Add some comments to keyboard driver

5 files changed, 33 insertions, 13 deletions

diff --git a/drivers/keyboard.cc b/drivers/keyboard.cc
index 268ce2b..09fd4e9 100644
--- a/drivers/keyboard.cc
+++ b/drivers/keyboard.cc
@@ -1,15 +1,28 @@
 #include "keyboard.h"
 #include <stdlib.h>
 
+/*
+ * https://wiki.osdev.org/%228042%22_PS/2_Controller
+ * https://wiki.osdev.org/PS/2_Keyboard
+ */
+
+constexpr uint8_t comm_enable_first_ps2 = 0xae;
+constexpr uint8_t comm_read_ctrl_config = 0x20;
+constexpr uint8_t comm_write_ctrl_config = 0x60;
+
+constexpr uint8_t dat_enable_scanning = 0xf4;
+
 Keyboard::Keyboard() : InterruptHandler(0x01) {
   // eat all previous keystrikes
-  while (commandport.read() & 0x1) dataport.read();
-  commandport.write(0xae);  // ???
-  commandport.write(0x20);  // get state ???
-  auto status = (dataport.read() | 1) & ~0x10;
-  commandport.write(0x60);  // set state ???
-  dataport.write(status);   // ???
-  dataport.write(0xf4);     // ???
+  while (commstatport.read() & 0x1) {
+    [[maybe_unused]] auto _c = dataport.read();
+  }
+  commstatport.write(comm_enable_first_ps2);
+  commstatport.write(comm_read_ctrl_config);
+  const uint8_t conf = (dataport.read() | 1) & ~0x10;
+  commstatport.write(comm_write_ctrl_config);
+  dataport.write(conf);
+  dataport.write(dat_enable_scanning);
 }
 
 void Keyboard::trigger() {
diff --git a/drivers/keyboard.h b/drivers/keyboard.h
index a14c2c0..cac0cb0 100644
--- a/drivers/keyboard.h
+++ b/drivers/keyboard.h
@@ -3,6 +3,7 @@
 #include "idt.h"
 #include "ports.h"
 
+/* PS/2 Keyboard */
 class Keyboard : public InterruptHandler {
 public:
   Keyboard();
@@ -10,6 +11,11 @@ public:
   void trigger() override;
 
 private:
-  keyboard_comm_t commandport;
-  keyboard_data_t dataport;
+  /* 8042 PS/2 Controller Ports */
+  typedef Port<0x60, uint8_t> data_port_t;  // rw  data port
+  typedef Port<0x64, uint8_t> comm_port_t;  // r   status register
+                                            //  w  command register
+
+  data_port_t dataport;
+  comm_port_t commstatport;
 };
diff --git a/drivers/ports.h b/drivers/ports.h
index 2d26e65..393fd4d 100644
--- a/drivers/ports.h
+++ b/drivers/ports.h
@@ -58,6 +58,3 @@ typedef Port<0x2e8, uint8_t> com4_port_t;
 typedef Port<0x20, uint8_t> pic1_t;
 typedef Port<0xa0, uint8_t> pic2_t;
 
-/* PS/2 keyboard */
-typedef Port<0x60, uint8_t> keyboard_data_t;
-typedef Port<0x64, uint8_t> keyboard_comm_t;
diff --git a/src/makefile b/src/makefile
index dda24af..8db63d6 100644
--- a/src/makefile
+++ b/src/makefile
@@ -14,7 +14,8 @@ src/cpu/irq.h: $(OBJ_DIR)/src/cpu/exceptions.o $(OBJ_DIR)/src/cpu/interrupts.o
 	@echo "  GEN $@"
 	@echo '#pragma once' > $@
 	@echo 'extern "C" {' >> $@
-	@for x in $^; do nm $$x -g | sed -nr 's/[0-9a-f]{8} T (.+)/void \1();/p'; done >> $@
+	@echo '/* interrupt map */' >> $@
+	@for x in $^; do $(NM) $$x -g | $(SED) -nr 's/[0-9a-f]{8} T (.+)/void \1();/p'; done >> $@
 	@echo '}' >> $@
 
 autogen := $(autogen) src/cpu/irq.h
diff --git a/toolchain.makefile b/toolchain.makefile
index 7a64904..0631904 100644
--- a/toolchain.makefile
+++ b/toolchain.makefile
@@ -1,6 +1,9 @@
 # Toolchain
 TARGET := i686-elf
 
+NM := llvm-nm
+SED := sed
+
 AS       := clang
 AS_FLAGS :=