#include "devices/kbd.h"
+#include <ctype.h>
#include <debug.h>
#include <stdio.h>
+#include <string.h>
+#include "devices/input.h"
+#include "threads/init.h"
#include "threads/interrupt.h"
#include "threads/io.h"
-static void
-irq21_keyboard (struct intr_frame *args UNUSED)
+/* Keyboard data register port. */
+#define DATA_REG 0x60
+
+/* Current state of shift keys.
+ True if depressed, false otherwise. */
+static bool left_shift, right_shift; /* Left and right Shift keys. */
+static bool left_alt, right_alt; /* Left and right Alt keys. */
+static bool left_ctrl, right_ctrl; /* Left and right Ctl keys. */
+
+/* Status of Caps Lock.
+ True when on, false when off. */
+static bool caps_lock;
+
+/* Number of keys pressed. */
+static int64_t key_cnt;
+
+static intr_handler_func keyboard_interrupt;
+
+/* Initializes the keyboard. */
+void
+kbd_init (void)
{
- printf ("Keyboard!\n");
- inb (0x60);
+ intr_register_ext (0x21, keyboard_interrupt, "8042 Keyboard");
}
+/* Prints keyboard statistics. */
void
-kbd_init (void)
+kbd_print_stats (void)
+{
+ printf ("Keyboard: %lld keys pressed\n", key_cnt);
+}
+\f
+/* Maps a set of contiguous scancodes into characters. */
+struct keymap
+ {
+ uint8_t first_scancode; /* First scancode. */
+ const char *chars; /* chars[0] has scancode first_scancode,
+ chars[1] has scancode first_scancode + 1,
+ and so on to the end of the string. */
+ };
+
+/* Keys that produce the same characters regardless of whether
+ the Shift keys are down. Case of letters is an exception
+ that we handle elsewhere. */
+static const struct keymap invariant_keymap[] =
+ {
+ {0x01, "\033"}, /* Escape. */
+ {0x0e, "\b"},
+ {0x0f, "\tQWERTYUIOP"},
+ {0x1c, "\r"},
+ {0x1e, "ASDFGHJKL"},
+ {0x2c, "ZXCVBNM"},
+ {0x37, "*"},
+ {0x39, " "},
+ {0x53, "\177"}, /* Delete. */
+ {0, NULL},
+ };
+
+/* Characters for keys pressed without Shift, for those keys
+ where it matters. */
+static const struct keymap unshifted_keymap[] =
+ {
+ {0x02, "1234567890-="},
+ {0x1a, "[]"},
+ {0x27, ";'`"},
+ {0x2b, "\\"},
+ {0x33, ",./"},
+ {0, NULL},
+ };
+
+/* Characters for keys pressed with Shift, for those keys where
+ it matters. */
+static const struct keymap shifted_keymap[] =
+ {
+ {0x02, "!@#$%^&*()_+"},
+ {0x1a, "{}"},
+ {0x27, ":\"~"},
+ {0x2b, "|"},
+ {0x33, "<>?"},
+ {0, NULL},
+ };
+
+static bool map_key (const struct keymap[], unsigned scancode, uint8_t *);
+
+static void
+keyboard_interrupt (struct intr_frame *args UNUSED)
{
- intr_register (0x21, 0, INTR_OFF, irq21_keyboard, "8042 Keyboard");
+ /* Status of shift keys. */
+ bool shift = left_shift || right_shift;
+ bool alt = left_alt || right_alt;
+ bool ctrl = left_ctrl || right_ctrl;
+
+ /* Keyboard scancode. */
+ unsigned code;
+
+ /* False if key pressed, true if key released. */
+ bool release;
+
+ /* Character that corresponds to `code'. */
+ uint8_t c;
+
+ /* Read scancode, including second byte if prefix code. */
+ code = inb (DATA_REG);
+ if (code == 0xe0)
+ code = (code << 8) | inb (DATA_REG);
+
+ /* Bit 0x80 distinguishes key press from key release
+ (even if there's a prefix). */
+ release = (code & 0x80) != 0;
+ code &= ~0x80u;
+
+ /* Interpret key. */
+ if (code == 0x3a)
+ {
+ /* Caps Lock. */
+ if (!release)
+ caps_lock = !caps_lock;
+ }
+ else if (map_key (invariant_keymap, code, &c)
+ || (!shift && map_key (unshifted_keymap, code, &c))
+ || (shift && map_key (shifted_keymap, code, &c)))
+ {
+ /* Ordinary character. */
+ if (!release)
+ {
+ /* Reboot if Ctrl+Alt+Del pressed. */
+ if (c == 0177 && ctrl && alt)
+ reboot ();
+
+ /* Handle Ctrl, Shift.
+ Note that Ctrl overrides Shift. */
+ if (ctrl && c >= 0x40 && c < 0x60)
+ {
+ /* A is 0x41, Ctrl+A is 0x01, etc. */
+ c -= 0x40;
+ }
+ else if (shift == caps_lock)
+ c = tolower (c);
+
+ /* Handle Alt by setting the high bit.
+ This 0x80 is unrelated to the one used to
+ distinguish key press from key release. */
+ if (alt)
+ c += 0x80;
+
+ /* Append to keyboard buffer. */
+ if (!input_full ())
+ {
+ key_cnt++;
+ input_putc (c);
+ }
+ }
+ }
+ else
+ {
+ /* Maps a keycode into a shift state variable. */
+ struct shift_key
+ {
+ unsigned scancode;
+ bool *state_var;
+ };
+
+ /* Table of shift keys. */
+ static const struct shift_key shift_keys[] =
+ {
+ { 0x2a, &left_shift},
+ { 0x36, &right_shift},
+ { 0x38, &left_alt},
+ {0xe038, &right_alt},
+ { 0x1d, &left_ctrl},
+ {0xe01d, &right_ctrl},
+ {0, NULL},
+ };
+
+ const struct shift_key *key;
+
+ /* Scan the table. */
+ for (key = shift_keys; key->scancode != 0; key++)
+ if (key->scancode == code)
+ {
+ *key->state_var = !release;
+ break;
+ }
+ }
+}
+
+/* Scans the array of keymaps K for SCANCODE.
+ If found, sets *C to the corresponding character and returns
+ true.
+ If not found, returns false and C is ignored. */
+static bool
+map_key (const struct keymap k[], unsigned scancode, uint8_t *c)
+{
+ for (; k->first_scancode != 0; k++)
+ if (scancode >= k->first_scancode
+ && scancode < k->first_scancode + strlen (k->chars))
+ {
+ *c = k->chars[scancode - k->first_scancode];
+ return true;
+ }
+
+ return false;
}
projects / pintos-anon / blobdiff