x86: new atcons and atkbd modules

These modules, together with cga, implement the AT console driver.

8 files changed, 955 insertions, 21 deletions

diff --git a/arch/x86/Makefrag.am b/arch/x86/Makefrag.am
index 6adc769f..0971530f 100644
--- a/arch/x86/Makefrag.am
+++ b/arch/x86/Makefrag.am
@@ -26,6 +26,10 @@ endif AMD64
 x15_SOURCES +=                          \
         arch/x86/machine/acpimp.c       \
         arch/x86/machine/acpimp.h       \
+        arch/x86/machine/atcons.c       \
+        arch/x86/machine/atcons.h       \
+        arch/x86/machine/atkbd.c        \
+        arch/x86/machine/atkbd.h        \
         arch/x86/machine/asm.h          \
         arch/x86/machine/atomic.h       \
         arch/x86/machine/biosmem.c      \
diff --git a/arch/x86/machine/atcons.c b/arch/x86/machine/atcons.c
new file mode 100644
index 00000000..c4c48069
--- /dev/null
+++ b/arch/x86/machine/atcons.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <kern/console.h>
+#include <kern/init.h>
+#include <machine/atcons.h>
+#include <machine/atkbd.h>
+#include <machine/cga.h>
+
+static struct console atcons_console;
+
+static void
+atcons_putc(struct console *console, char c)
+{
+    (void)console;
+    cga_putc(c);
+}
+
+static const struct console_ops atcons_ops = {
+    .putc = atcons_putc,
+};
+
+void __init
+atcons_bootstrap(void)
+{
+    cga_setup();
+
+    console_init(&atcons_console, "atcons", &atcons_ops);
+    console_register(&atcons_console);
+}
+
+void __init
+atcons_setup(void)
+{
+    atkbd_setup();
+}
+
+void
+atcons_intr(char c)
+{
+    console_intr(&atcons_console, c);
+}
diff --git a/arch/x86/machine/atcons.h b/arch/x86/machine/atcons.h
new file mode 100644
index 00000000..05b870fc
--- /dev/null
+++ b/arch/x86/machine/atcons.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * AT console driver.
+ */
+
+#ifndef _X86_ATCONS_H
+#define _X86_ATCONS_H
+
+/*
+ * Early initialization of the atcons module.
+ */
+void atcons_bootstrap(void);
+
+/*
+ * Initialize the atcons module.
+ *
+ * This function enables keyboard interrupt handling.
+ */
+void atcons_setup(void);
+
+/*
+ * Console interrupt handler.
+ *
+ * This function is called by the AT keyboard interrupt handler
+ * to handle machine-independent console management.
+ */
+void atcons_intr(char c);
+
+#endif /* _X86_ATCONS_H */
diff --git a/arch/x86/machine/atkbd.c b/arch/x86/machine/atkbd.c
new file mode 100644
index 00000000..362b834c
--- /dev/null
+++ b/arch/x86/machine/atkbd.c
@@ -0,0 +1,811 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include <kern/error.h>
+#include <kern/init.h>
+#include <kern/intr.h>
+#include <kern/macros.h>
+#include <machine/atkbd.h>
+#include <machine/atcons.h>
+#include <machine/io.h>
+
+#define ATKBD_PORT_DATA             0x60
+#define ATKBD_PORT_STATUS           0x64
+#define ATKBD_PORT_CMD              0x64
+
+#define ATKBD_REQ_LEDS              0xed
+#define ATKBD_REQ_RESET             0xff
+
+#define ATKBD_REP_PASS              0xaa
+#define ATKBD_REP_ACK               0xfa
+#define ATKBD_REP_RESEND            0xfe
+
+#define ATKBD_LEDS_SCROLLLOCK       0x01
+#define ATKBD_LEDS_NUMLOCK          0x02
+#define ATKBD_LEDS_CAPSLOCK         0x04
+
+#define ATKBD_STATUS_OUT_FULL       0x01
+#define ATKBD_STATUS_IN_FULL        0x02
+#define ATKBD_STATUS_PARITY_ERROR   0x80
+
+#define ATKBD_CMD_RDCONF            0x20
+#define ATKBD_CMD_WRCONF            0x60
+#define ATKBD_CMD_DIS2              0xa7
+#define ATKBD_CMD_EN2               0xa8
+#define ATKBD_CMD_DIS1              0xad
+#define ATKBD_CMD_EN1               0xae
+
+#define ATKBD_CONF_ENINT1           0x01
+#define ATKBD_CONF_ENINT2           0x02
+#define ATKBD_CONF_ENTRANS          0x40
+
+#define ATKBD_INTR1                 1
+
+enum atkbd_key_id {
+    ATKBD_KEY_INVALID = 0,
+    ATKBD_KEY_1 = 1,
+    ATKBD_KEY_2,
+    ATKBD_KEY_3,
+    ATKBD_KEY_4,
+    ATKBD_KEY_5,
+    ATKBD_KEY_6,
+    ATKBD_KEY_7,
+    ATKBD_KEY_8,
+    ATKBD_KEY_9,
+    ATKBD_KEY_0,
+    ATKBD_KEY_DASH,
+    ATKBD_KEY_EQUAL,
+    ATKBD_KEY_BACKSLASH,
+    ATKBD_KEY_BACKSPACE,
+
+    ATKBD_KEY_TAB,
+    ATKBD_KEY_Q,
+    ATKBD_KEY_W,
+    ATKBD_KEY_E,
+    ATKBD_KEY_R,
+    ATKBD_KEY_T,
+    ATKBD_KEY_Y,
+    ATKBD_KEY_U,
+    ATKBD_KEY_I,
+    ATKBD_KEY_O,
+    ATKBD_KEY_P,
+    ATKBD_KEY_OBRACKET,
+    ATKBD_KEY_CBRACKET,
+    ATKBD_KEY_ENTER,
+
+    ATKBD_KEY_CAPSLOCK,
+    ATKBD_KEY_A,
+    ATKBD_KEY_S,
+    ATKBD_KEY_D,
+    ATKBD_KEY_F,
+    ATKBD_KEY_G,
+    ATKBD_KEY_H,
+    ATKBD_KEY_J,
+    ATKBD_KEY_K,
+    ATKBD_KEY_L,
+    ATKBD_KEY_SEMICOLON,
+    ATKBD_KEY_QUOTE,
+
+    ATKBD_KEY_LSHIFT,
+    ATKBD_KEY_Z,
+    ATKBD_KEY_X,
+    ATKBD_KEY_C,
+    ATKBD_KEY_V,
+    ATKBD_KEY_B,
+    ATKBD_KEY_N,
+    ATKBD_KEY_M,
+    ATKBD_KEY_COMMA,
+    ATKBD_KEY_DOT,
+    ATKBD_KEY_SLASH,
+    ATKBD_KEY_RSHIFT,
+
+    ATKBD_KEY_LCTRL,
+    ATKBD_KEY_ALT,
+    ATKBD_KEY_SPACE,
+    ATKBD_KEY_ALTGR,
+    ATKBD_KEY_RCTRL,
+
+    ATKBD_KEY_INSERT,
+    ATKBD_KEY_DELETE,
+    ATKBD_KEY_HOME,
+    ATKBD_KEY_END,
+    ATKBD_KEY_PGUP,
+    ATKBD_KEY_PGDOWN,
+
+    ATKBD_KEY_LEFT,
+    ATKBD_KEY_BOTTOM,
+    ATKBD_KEY_RIGHT,
+    ATKBD_KEY_UP,
+
+    ATKBD_KEY_KP_NUMLOCK,
+    ATKBD_KEY_KP_SLASH,
+    ATKBD_KEY_KP_STAR,
+    ATKBD_KEY_KP_MINUS,
+    ATKBD_KEY_KP_HOME,
+    ATKBD_KEY_KP_UP,
+    ATKBD_KEY_KP_PGUP,
+    ATKBD_KEY_KP_PLUS,
+    ATKBD_KEY_KP_LEFT,
+    ATKBD_KEY_KP_5,
+    ATKBD_KEY_KP_RIGHT,
+    ATKBD_KEY_KP_END,
+    ATKBD_KEY_KP_BOTTOM,
+    ATKBD_KEY_KP_PGDOWN,
+    ATKBD_KEY_KP_ENTER,
+    ATKBD_KEY_KP_INS,
+    ATKBD_KEY_KP_DEL,
+};
+
+#define ATKBD_KM_SHIFT      0x01 /* Shift / caps lock modifier applies */
+#define ATKBD_KM_KP         0x02 /* Num lock modifier applies */
+#define ATKBD_KM_CTL        0x04 /* Unmodified key is a control character */
+
+struct atkbd_key {
+    int modifiers;
+    enum atkbd_key_id id;
+};
+
+static const struct atkbd_key atkbd_keys[] = {
+    [0x16] = { ATKBD_KM_SHIFT, ATKBD_KEY_1 },
+    [0x1e] = { ATKBD_KM_SHIFT, ATKBD_KEY_2 },
+    [0x26] = { ATKBD_KM_SHIFT, ATKBD_KEY_3 },
+    [0x25] = { ATKBD_KM_SHIFT, ATKBD_KEY_4 },
+    [0x2e] = { ATKBD_KM_SHIFT, ATKBD_KEY_5 },
+    [0x36] = { ATKBD_KM_SHIFT, ATKBD_KEY_6 },
+    [0x3d] = { ATKBD_KM_SHIFT, ATKBD_KEY_7 },
+    [0x3e] = { ATKBD_KM_SHIFT, ATKBD_KEY_8 },
+    [0x46] = { ATKBD_KM_SHIFT, ATKBD_KEY_9 },
+    [0x45] = { ATKBD_KM_SHIFT, ATKBD_KEY_0 },
+    [0x4e] = { ATKBD_KM_SHIFT, ATKBD_KEY_DASH },
+    [0x55] = { ATKBD_KM_SHIFT, ATKBD_KEY_EQUAL },
+    [0x5d] = { ATKBD_KM_SHIFT, ATKBD_KEY_BACKSLASH },
+    [0x66] = { 0, ATKBD_KEY_BACKSPACE },
+
+    [0x0d] = { 0, ATKBD_KEY_TAB },
+    [0x15] = { ATKBD_KM_SHIFT, ATKBD_KEY_Q },
+    [0x1d] = { ATKBD_KM_SHIFT, ATKBD_KEY_W },
+    [0x24] = { ATKBD_KM_SHIFT, ATKBD_KEY_E },
+    [0x2d] = { ATKBD_KM_SHIFT, ATKBD_KEY_R },
+    [0x2c] = { ATKBD_KM_SHIFT, ATKBD_KEY_T },
+    [0x35] = { ATKBD_KM_SHIFT, ATKBD_KEY_Y },
+    [0x3c] = { ATKBD_KM_SHIFT, ATKBD_KEY_U },
+    [0x43] = { ATKBD_KM_SHIFT, ATKBD_KEY_I },
+    [0x44] = { ATKBD_KM_SHIFT, ATKBD_KEY_O },
+    [0x4d] = { ATKBD_KM_SHIFT, ATKBD_KEY_P },
+    [0x54] = { ATKBD_KM_SHIFT, ATKBD_KEY_OBRACKET },
+    [0x5b] = { ATKBD_KM_SHIFT, ATKBD_KEY_CBRACKET },
+    [0x5a] = { 0, ATKBD_KEY_ENTER },
+
+    [0x58] = { ATKBD_KM_CTL, ATKBD_KEY_CAPSLOCK },
+    [0x1c] = { ATKBD_KM_SHIFT, ATKBD_KEY_A },
+    [0x1b] = { ATKBD_KM_SHIFT, ATKBD_KEY_S },
+    [0x23] = { ATKBD_KM_SHIFT, ATKBD_KEY_D },
+    [0x2b] = { ATKBD_KM_SHIFT, ATKBD_KEY_F },
+    [0x34] = { ATKBD_KM_SHIFT, ATKBD_KEY_G },
+    [0x33] = { ATKBD_KM_SHIFT, ATKBD_KEY_H },
+    [0x3b] = { ATKBD_KM_SHIFT, ATKBD_KEY_J },
+    [0x42] = { ATKBD_KM_SHIFT, ATKBD_KEY_K },
+    [0x4b] = { ATKBD_KM_SHIFT, ATKBD_KEY_L },
+    [0x4c] = { ATKBD_KM_SHIFT, ATKBD_KEY_SEMICOLON },
+    [0x52] = { ATKBD_KM_SHIFT, ATKBD_KEY_QUOTE },
+
+    [0x12] = { ATKBD_KM_CTL, ATKBD_KEY_LSHIFT },
+    [0x1a] = { ATKBD_KM_SHIFT, ATKBD_KEY_Z },
+    [0x22] = { ATKBD_KM_SHIFT, ATKBD_KEY_X },
+    [0x21] = { ATKBD_KM_SHIFT, ATKBD_KEY_C },
+    [0x2a] = { ATKBD_KM_SHIFT, ATKBD_KEY_V },
+    [0x32] = { ATKBD_KM_SHIFT, ATKBD_KEY_B },
+    [0x31] = { ATKBD_KM_SHIFT, ATKBD_KEY_N },
+    [0x3a] = { ATKBD_KM_SHIFT, ATKBD_KEY_M },
+    [0x41] = { ATKBD_KM_SHIFT, ATKBD_KEY_COMMA },
+    [0x49] = { ATKBD_KM_SHIFT, ATKBD_KEY_DOT },
+    [0x4a] = { ATKBD_KM_SHIFT, ATKBD_KEY_SLASH },
+    [0x59] = { ATKBD_KM_CTL, ATKBD_KEY_RSHIFT },
+
+    [0x14] = { ATKBD_KM_CTL, ATKBD_KEY_LCTRL },
+    [0x11] = { ATKBD_KM_CTL, ATKBD_KEY_ALT },
+    [0x29] = { 0, ATKBD_KEY_SPACE },
+
+    [0x77] = { ATKBD_KM_CTL, ATKBD_KEY_KP_NUMLOCK },
+    [0x7c] = { 0, ATKBD_KEY_KP_STAR },
+    [0x7b] = { 0, ATKBD_KEY_KP_MINUS },
+    [0x6c] = { ATKBD_KM_KP, ATKBD_KEY_KP_HOME },
+    [0x75] = { ATKBD_KM_KP, ATKBD_KEY_KP_UP },
+    [0x7d] = { ATKBD_KM_KP, ATKBD_KEY_KP_PGUP },
+    [0x79] = { 0, ATKBD_KEY_KP_PLUS },
+    [0x6b] = { ATKBD_KM_KP, ATKBD_KEY_KP_LEFT },
+    [0x73] = { 0, ATKBD_KEY_KP_5 },
+    [0x74] = { ATKBD_KM_KP, ATKBD_KEY_KP_RIGHT },
+    [0x69] = { ATKBD_KM_KP, ATKBD_KEY_KP_END },
+    [0x72] = { ATKBD_KM_KP, ATKBD_KEY_KP_BOTTOM },
+    [0x7a] = { ATKBD_KM_KP, ATKBD_KEY_KP_PGDOWN },
+    [0x70] = { ATKBD_KM_CTL | ATKBD_KM_KP, ATKBD_KEY_KP_INS },
+    [0x71] = { ATKBD_KM_KP, ATKBD_KEY_KP_DEL },
+};
+
+static const struct atkbd_key atkbd_e0_keys[] = {
+    [0x11] = { ATKBD_KM_CTL, ATKBD_KEY_ALTGR },
+    [0x14] = { ATKBD_KM_CTL, ATKBD_KEY_RCTRL },
+
+    [0x70] = { ATKBD_KM_CTL, ATKBD_KEY_INSERT },
+    [0x71] = { 0, ATKBD_KEY_DELETE },
+    [0x6c] = { 0, ATKBD_KEY_HOME },
+    [0x69] = { 0, ATKBD_KEY_END },
+    [0x7d] = { 0, ATKBD_KEY_PGUP },
+    [0x7a] = { 0, ATKBD_KEY_PGDOWN },
+
+    [0x6b] = { 0, ATKBD_KEY_LEFT },
+    [0x72] = { 0, ATKBD_KEY_BOTTOM },
+    [0x74] = { 0, ATKBD_KEY_RIGHT },
+    [0x75] = { 0, ATKBD_KEY_UP },
+
+    [0x4a] = { 0, ATKBD_KEY_KP_SLASH },
+    [0x5a] = { 0, ATKBD_KEY_KP_ENTER },
+};
+
+static const char *atkbd_chars[] = {
+    [ATKBD_KEY_1] = "1",
+    [ATKBD_KEY_2] = "2",
+    [ATKBD_KEY_3] = "3",
+    [ATKBD_KEY_4] = "4",
+    [ATKBD_KEY_5] = "5",
+    [ATKBD_KEY_6] = "6",
+    [ATKBD_KEY_7] = "7",
+    [ATKBD_KEY_8] = "8",
+    [ATKBD_KEY_9] = "9",
+    [ATKBD_KEY_0] = "0",
+    [ATKBD_KEY_DASH] = "-",
+    [ATKBD_KEY_EQUAL] = "=",
+    [ATKBD_KEY_BACKSLASH] = "\\",
+    [ATKBD_KEY_BACKSPACE] = "\b",
+
+    [ATKBD_KEY_TAB] = "\t",
+    [ATKBD_KEY_Q] = "q",
+    [ATKBD_KEY_W] = "w",
+    [ATKBD_KEY_E] = "e",
+    [ATKBD_KEY_R] = "r",
+    [ATKBD_KEY_T] = "t",
+    [ATKBD_KEY_Y] = "y",
+    [ATKBD_KEY_U] = "u",
+    [ATKBD_KEY_I] = "i",
+    [ATKBD_KEY_O] = "o",
+    [ATKBD_KEY_P] = "p",
+    [ATKBD_KEY_OBRACKET] = "[",
+    [ATKBD_KEY_CBRACKET] = "]",
+    [ATKBD_KEY_ENTER] = "\n",
+
+    [ATKBD_KEY_A] = "a",
+    [ATKBD_KEY_S] = "s",
+    [ATKBD_KEY_D] = "d",
+    [ATKBD_KEY_F] = "f",
+    [ATKBD_KEY_G] = "g",
+    [ATKBD_KEY_H] = "h",
+    [ATKBD_KEY_J] = "j",
+    [ATKBD_KEY_K] = "k",
+    [ATKBD_KEY_L] = "l",
+    [ATKBD_KEY_SEMICOLON] = ";",
+    [ATKBD_KEY_QUOTE] = "'",
+
+    [ATKBD_KEY_Z] = "z",
+    [ATKBD_KEY_X] = "x",
+    [ATKBD_KEY_C] = "c",
+    [ATKBD_KEY_V] = "v",
+    [ATKBD_KEY_B] = "b",
+    [ATKBD_KEY_N] = "n",
+    [ATKBD_KEY_M] = "m",
+    [ATKBD_KEY_COMMA] = ",",
+    [ATKBD_KEY_DOT] = ".",
+    [ATKBD_KEY_SLASH] = "/",
+
+    [ATKBD_KEY_SPACE] = " ",
+
+    [ATKBD_KEY_DELETE] = "\e[3~",
+
+    [ATKBD_KEY_LEFT] = "\e[D",
+    [ATKBD_KEY_BOTTOM] = "\e[B",
+    [ATKBD_KEY_RIGHT] = "\e[C",
+    [ATKBD_KEY_UP] = "\e[A",
+
+    [ATKBD_KEY_KP_SLASH] = "/",
+    [ATKBD_KEY_KP_STAR] = "*",
+    [ATKBD_KEY_KP_MINUS] = "-",
+    [ATKBD_KEY_KP_PLUS] = "+",
+    [ATKBD_KEY_KP_5] = "5",
+    [ATKBD_KEY_KP_ENTER] = "\n",
+    [ATKBD_KEY_KP_DEL] = "\e[3~",
+};
+
+static const char *atkbd_shift_chars[] = {
+    [ATKBD_KEY_1] = "!",
+    [ATKBD_KEY_2] = "@",
+    [ATKBD_KEY_3] = "#",
+    [ATKBD_KEY_4] = "$",
+    [ATKBD_KEY_5] = "%",
+    [ATKBD_KEY_6] = "^",
+    [ATKBD_KEY_7] = "&",
+    [ATKBD_KEY_8] = "*",
+    [ATKBD_KEY_9] = "(",
+    [ATKBD_KEY_0] = ")",
+    [ATKBD_KEY_DASH] = "_",
+    [ATKBD_KEY_EQUAL] = "+",
+    [ATKBD_KEY_BACKSLASH] = "|",
+
+    [ATKBD_KEY_Q] = "Q",
+    [ATKBD_KEY_W] = "W",
+    [ATKBD_KEY_E] = "E",
+    [ATKBD_KEY_R] = "R",
+    [ATKBD_KEY_T] = "T",
+    [ATKBD_KEY_Y] = "Y",
+    [ATKBD_KEY_U] = "U",
+    [ATKBD_KEY_I] = "I",
+    [ATKBD_KEY_O] = "O",
+    [ATKBD_KEY_P] = "P",
+    [ATKBD_KEY_OBRACKET] = "{",
+    [ATKBD_KEY_CBRACKET] = "}",
+
+    [ATKBD_KEY_A] = "A",
+    [ATKBD_KEY_S] = "S",
+    [ATKBD_KEY_D] = "D",
+    [ATKBD_KEY_F] = "F",
+    [ATKBD_KEY_G] = "G",
+    [ATKBD_KEY_H] = "H",
+    [ATKBD_KEY_J] = "J",
+    [ATKBD_KEY_K] = "K",
+    [ATKBD_KEY_L] = "L",
+    [ATKBD_KEY_SEMICOLON] = ":",
+    [ATKBD_KEY_QUOTE] = "\"",
+
+    [ATKBD_KEY_Z] = "Z",
+    [ATKBD_KEY_X] = "X",
+    [ATKBD_KEY_C] = "C",
+    [ATKBD_KEY_V] = "V",
+    [ATKBD_KEY_B] = "B",
+    [ATKBD_KEY_N] = "N",
+    [ATKBD_KEY_M] = "M",
+    [ATKBD_KEY_COMMA] = "<",
+    [ATKBD_KEY_DOT] = ">",
+    [ATKBD_KEY_SLASH] = "?",
+};
+
+static const char *atkbd_kp_chars[] = {
+    [ATKBD_KEY_KP_HOME] = "7",
+    [ATKBD_KEY_KP_UP] = "8",
+    [ATKBD_KEY_KP_PGUP] = "9",
+    [ATKBD_KEY_KP_LEFT] = "4",
+    [ATKBD_KEY_KP_RIGHT] = "6",
+    [ATKBD_KEY_KP_END] = "1",
+    [ATKBD_KEY_KP_BOTTOM] = "2",
+    [ATKBD_KEY_KP_PGDOWN] = "3",
+    [ATKBD_KEY_KP_INS] = "0",
+    [ATKBD_KEY_KP_DEL] = ".",
+};
+
+#define ATKBD_KF_E0         0x01
+#define ATKBD_KF_F0         0x02
+#define ATKBD_KF_LSHIFT     0x04
+#define ATKBD_KF_RSHIFT     0x08
+#define ATKBD_KF_NUMLOCK    0x10
+#define ATKBD_KF_CAPSLOCK   0x20
+#define ATKBD_KF_SCROLLLOCK 0x40
+
+#define ATKBD_KF_SHIFT      (ATKBD_KF_CAPSLOCK  \
+                             | ATKBD_KF_RSHIFT  \
+                             | ATKBD_KF_LSHIFT)
+
+/*
+ * These flags are only accessed during interrupt handling and don't
+ * require additional synchronization.
+ */
+static unsigned int atkbd_flags;
+
+static uint8_t
+atkbd_read_data(void)
+{
+    return io_read_byte(ATKBD_PORT_DATA);
+}
+
+static void
+atkbd_write_data(uint8_t data)
+{
+    io_write_byte(ATKBD_PORT_DATA, data);
+}
+
+static uint8_t
+atkbd_read_status(void)
+{
+    return io_read_byte(ATKBD_PORT_STATUS);
+}
+
+static void
+atkbd_write_cmd(uint8_t cmd)
+{
+    io_write_byte(ATKBD_PORT_CMD, cmd);
+}
+
+static int
+atkbd_out_wait(void)
+{
+    uint8_t status;
+
+    for (;;) {
+        status = atkbd_read_status();
+
+        if (status & ATKBD_STATUS_OUT_FULL) {
+            break;
+        }
+    }
+
+    if (status & ATKBD_STATUS_PARITY_ERROR) {
+        printf("atkbd: parity error\n");
+        return ERROR_IO;
+    }
+
+    return 0;
+}
+
+static void
+atkbd_in_wait(void)
+{
+    uint8_t status;
+
+    for (;;) {
+        status = atkbd_read_status();
+
+        if (!(status & ATKBD_STATUS_IN_FULL)) {
+            break;
+        }
+    }
+}
+
+static int
+atkbd_read(uint8_t *datap, bool wait)
+{
+    uint8_t status;
+    int error;
+
+    if (wait) {
+        error = atkbd_out_wait();
+
+        if (error) {
+            return error;
+        }
+    } else {
+        status = atkbd_read_status();
+
+        if (!(status & ATKBD_STATUS_OUT_FULL)) {
+            return ERROR_AGAIN;
+        }
+    }
+
+    *datap = atkbd_read_data();
+    return 0;
+}
+
+static void
+atkbd_write(uint8_t data)
+{
+    atkbd_in_wait();
+    atkbd_write_data(data);
+}
+
+static void
+atkbd_flush(void)
+{
+    uint8_t status;
+
+    atkbd_read(&status, false);
+}
+
+static void __init
+atkbd_reset_kbd(void)
+{
+    uint8_t reply;
+    int error;
+
+resend:
+    atkbd_write(ATKBD_REQ_RESET);
+    error = atkbd_read(&reply, true);
+
+    if (error) {
+        return;
+    }
+
+    if (reply == ATKBD_REP_RESEND) {
+        goto resend;
+    }
+
+    if ((reply != ATKBD_REP_PASS) && (reply != ATKBD_REP_ACK)) {
+        printf("atkbd: warning: unable to reset keyboard\n");
+    }
+}
+
+static int __init
+atkbd_disable(void)
+{
+    uint8_t byte;
+    int error;
+
+    atkbd_write_cmd(ATKBD_CMD_DIS1);
+    atkbd_write_cmd(ATKBD_CMD_DIS2);
+
+    atkbd_flush();
+
+    atkbd_write_cmd(ATKBD_CMD_RDCONF);
+    error = atkbd_read(&byte, true);
+
+    if (error) {
+        return error;
+    }
+
+    byte &= ~(ATKBD_CONF_ENTRANS | ATKBD_CONF_ENINT2 | ATKBD_CONF_ENINT1);
+    atkbd_write_cmd(ATKBD_CMD_WRCONF);
+    atkbd_write(byte);
+
+    return 0;
+}
+
+static int __init
+atkbd_enable(void)
+{
+    uint8_t byte;
+    int error;
+
+    atkbd_write_cmd(ATKBD_CMD_EN1);
+
+    atkbd_write_cmd(ATKBD_CMD_RDCONF);
+    error = atkbd_read(&byte, true);
+
+    if (error) {
+        return error;
+    }
+
+    byte &= ~(ATKBD_CONF_ENTRANS | ATKBD_CONF_ENINT2);
+    byte |= ATKBD_CONF_ENINT1;
+    atkbd_write_cmd(ATKBD_CMD_WRCONF);
+    atkbd_write(byte);
+
+    atkbd_flush();
+
+    return 0;
+}
+
+static void
+atkbd_set_leds(void)
+{
+    uint8_t leds, reply;
+    int error;
+
+    leds = ((atkbd_flags & ATKBD_KF_NUMLOCK) ? ATKBD_LEDS_NUMLOCK : 0)
+           | ((atkbd_flags & ATKBD_KF_CAPSLOCK) ? ATKBD_LEDS_CAPSLOCK : 0)
+           | ((atkbd_flags & ATKBD_KF_SCROLLLOCK) ? ATKBD_LEDS_SCROLLLOCK : 0);
+
+resend:
+    atkbd_write(ATKBD_REQ_LEDS);
+    atkbd_write(leds);
+    error = atkbd_read(&reply, true);
+
+    if (error) {
+        return;
+    }
+
+    if (reply == ATKBD_REP_RESEND) {
+        goto resend;
+    }
+
+    if (reply != ATKBD_REP_ACK) {
+        printf("atkbd: warning: invalid reply from keyboard\n");
+    }
+}
+
+static void
+atkbd_toggle_numlock(void)
+{
+    atkbd_flags ^= ATKBD_KF_NUMLOCK;
+    atkbd_set_leds();
+}
+
+static void
+atkbd_toggle_capslock(void)
+{
+    atkbd_flags ^= ATKBD_KF_CAPSLOCK;
+    atkbd_set_leds();
+}
+
+static void
+atkbd_key_process_chars(const struct atkbd_key *key,
+                        const char **chars, size_t size)
+{
+    const char *s;
+
+    if (key->id >= size) {
+        return;
+    }
+
+    if (atkbd_flags & ATKBD_KF_F0) {
+        return;
+    }
+
+    s = chars[key->id];
+
+    if (s != NULL) {
+        while (*s != '\0') {
+            atcons_intr(*s);
+            s++;
+        }
+    }
+}
+
+static void
+atkbd_key_process_shift(const struct atkbd_key *key)
+{
+    atkbd_key_process_chars(key, atkbd_shift_chars,
+                            ARRAY_SIZE(atkbd_shift_chars));
+}
+
+static void
+atkbd_key_process_kp(const struct atkbd_key *key)
+{
+    atkbd_key_process_chars(key, atkbd_kp_chars,
+                            ARRAY_SIZE(atkbd_kp_chars));
+}
+
+static void
+atkbd_key_process_ctl(const struct atkbd_key *key)
+{
+    switch (key->id) {
+    case ATKBD_KEY_LSHIFT:
+        if (atkbd_flags & ATKBD_KF_F0) {
+            atkbd_flags &= ~ATKBD_KF_LSHIFT;
+        } else {
+            atkbd_flags |= ATKBD_KF_LSHIFT;
+        }
+
+        break;
+    case ATKBD_KEY_RSHIFT:
+        if (atkbd_flags & ATKBD_KF_F0) {
+            atkbd_flags &= ~ATKBD_KF_RSHIFT;
+        } else {
+            atkbd_flags |= ATKBD_KF_RSHIFT;
+        }
+
+        break;
+    case ATKBD_KEY_KP_NUMLOCK:
+        if (!(atkbd_flags & ATKBD_KF_F0)) {
+            atkbd_toggle_numlock();
+        }
+
+        break;
+    case ATKBD_KEY_CAPSLOCK:
+        if (!(atkbd_flags & ATKBD_KF_F0)) {
+            atkbd_toggle_capslock();
+        }
+    default:
+        break;
+    }
+}
+
+static void
+atkbd_key_process(const struct atkbd_key *key)
+{
+    if (key->id == ATKBD_KEY_INVALID) {
+        return;
+    }
+
+    if ((key->modifiers & ATKBD_KM_SHIFT) && (atkbd_flags & ATKBD_KF_SHIFT)) {
+        atkbd_key_process_shift(key);
+    } else if ((key->modifiers & ATKBD_KM_KP)
+               && (atkbd_flags & ATKBD_KF_NUMLOCK)) {
+        atkbd_key_process_kp(key);
+    } else if (key->modifiers & ATKBD_KM_CTL) {
+        atkbd_key_process_ctl(key);
+    } else {
+        atkbd_key_process_chars(key, atkbd_chars, ARRAY_SIZE(atkbd_chars));
+    }
+
+    atkbd_flags &= ~ATKBD_KF_F0;
+}
+
+static void
+atkbd_process_e0_code(uint8_t code)
+{
+    if (code == 0xf0) {
+        atkbd_flags |= ATKBD_KF_F0;
+        return;
+    }
+
+    if (code >= ARRAY_SIZE(atkbd_keys)) {
+        return;
+    }
+
+    atkbd_key_process(&atkbd_e0_keys[code]);
+    atkbd_flags &= ~ATKBD_KF_E0;
+}
+
+static void
+atkbd_process_code(uint8_t code)
+{
+    if (code == 0xe0) {
+        atkbd_flags |= ATKBD_KF_E0;
+        return;
+    } else if (code == 0xf0) {
+        atkbd_flags |= ATKBD_KF_F0;
+        return;
+    }
+
+    if (code >= ARRAY_SIZE(atkbd_keys)) {
+        return;
+    }
+
+    atkbd_key_process(&atkbd_keys[code]);
+}
+
+static int
+atkbd_intr(void *arg)
+{
+    uint8_t code;
+    int error;
+
+    (void)arg;
+
+    for (;;) {
+        error = atkbd_read(&code, false);
+
+        if (error) {
+            return 0;
+        }
+
+        if (atkbd_flags & ATKBD_KF_E0) {
+            atkbd_process_e0_code(code);
+        } else {
+            atkbd_process_code(code);
+        }
+    }
+
+    return 0;
+}
+
+void __init
+atkbd_setup(void)
+{
+    int error;
+
+    error = atkbd_disable();
+
+    if (error) {
+        return;
+    }
+
+    error = intr_register(ATKBD_INTR1, atkbd_intr, NULL);
+
+    if (error) {
+        printf("atkbd: error: unable to register interrupt handler\n");
+        return;
+    }
+
+    error = atkbd_enable();
+
+    if (error) {
+        return;
+    }
+
+    atkbd_reset_kbd();
+}
diff --git a/arch/x86/machine/atkbd.h b/arch/x86/machine/atkbd.h
new file mode 100644
index 00000000..0bed7ada
--- /dev/null
+++ b/arch/x86/machine/atkbd.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Tiny AT keyboard driver.
+ */
+
+#ifndef _X86_ATKBD_H
+#define _X86_ATKBD_H
+
+/*
+ * Initialize the atkbd module.
+ */
+void atkbd_setup(void);
+
+#endif /* _X86_ATKBD_H */
diff --git a/arch/x86/machine/boot.c b/arch/x86/machine/boot.c
index 0df96747..b7a9b0ee 100644
--- a/arch/x86/machine/boot.c
+++ b/arch/x86/machine/boot.c
@@ -63,6 +63,7 @@
 #include <kern/syscnt.h>
 #include <kern/thread.h>
 #include <kern/turnstile.h>
+#include <machine/atcons.h>
 #include <machine/biosmem.h>
 #include <machine/boot.h>
 #include <machine/cga.h>
@@ -468,7 +469,7 @@ boot_main(void)
     cpu_setup();
     thread_bootstrap();
     console_setup();
-    cga_setup();
+    atcons_bootstrap();
     uart_bootstrap();
     printf_setup();
     boot_show_version();
@@ -485,6 +486,7 @@ boot_main(void)
     intr_setup();
     cpu_mp_probe();
     pic_setup();
+    atcons_setup();
     uart_setup();
     kernel_main();
 
diff --git a/arch/x86/machine/cga.c b/arch/x86/machine/cga.c
index 3f1525c2..1ec80354 100644
--- a/arch/x86/machine/cga.c
+++ b/arch/x86/machine/cga.c
@@ -18,7 +18,6 @@
 #include <stdint.h>
 #include <string.h>
 
-#include <kern/console.h>
 #include <kern/init.h>
 #include <kern/macros.h>
 #include <kern/param.h>
@@ -70,8 +69,6 @@
 static uint8_t *cga_memory __read_mostly;
 static uint16_t cga_cursor;
 
-static struct console cga_console;
-
 static uint16_t
 cga_get_cursor_position(void)
 {
@@ -119,8 +116,8 @@ cga_scroll_lines(void)
     }
 }
 
-static void
-cga_write_char(char c)
+void
+cga_putc(char c)
 {
     if (c == '\r') {
         return;
@@ -143,7 +140,7 @@ cga_write_char(char c)
         int i;
 
         for(i = 0; i < CGA_TABULATION_SPACES; i++) {
-            cga_write_char(' ');
+            cga_putc(' ');
         }
     } else {
         if ((cga_cursor + 1) >= CGA_COLUMNS * CGA_LINES) {
@@ -158,17 +155,6 @@ cga_write_char(char c)
     }
 }
 
-static void
-cga_console_putc(struct console *console, char c)
-{
-    (void)console;
-    cga_write_char(c);
-}
-
-static const struct console_ops cga_console_ops = {
-    .putc = cga_console_putc,
-};
-
 void __init
 cga_setup(void)
 {
@@ -194,7 +180,4 @@ cga_setup(void)
     }
 
     cga_cursor = cga_get_cursor_position();
-
-    console_init(&cga_console, "cga", &cga_console_ops);
-    console_register(&cga_console);
 }
diff --git a/arch/x86/machine/cga.h b/arch/x86/machine/cga.h
index a6771621..f5a5d285 100644
--- a/arch/x86/machine/cga.h
+++ b/arch/x86/machine/cga.h
@@ -26,4 +26,9 @@
  */
 void cga_setup(void);
 
+/*
+ * Append a character to the CGA screen.
+ */
+void cga_putc(char c);
+
 #endif /* _X86_CGA_H */