drivers: basic keyboard support

Basic keyboard support with PIC interrupt

Signed-off-by: Daniele Ahmed <ahmeddan 2 amazon ;com>

arch/x86/entry.S

@@ -96,6 +96,7 @@ END_FUNC(handle_exception)
 
 interrupt_handler pit pit_interrupt_handler
 interrupt_handler uart uart_interrupt_handler
+interrupt_handler keyboard keyboard_interrupt_handler
 
 ENTRY(usermode_call_asm)
     /* FIXME: Add 32-bit support */

arch/x86/traps.c

@@ -26,6 +26,7 @@
 #include <console.h>
 #include <drivers/pit.h>
 #include <drivers/serial.h>
+#include <drivers/keyboard.h>
 #include <ktf.h>
 #include <lib.h>
 #include <percpu.h>
@@ -40,6 +41,7 @@
 
 extern void asm_interrupt_handler_uart(void);
 extern void asm_interrupt_handler_pit(void);
+extern void asm_interrupt_handler_keyboard(void);
 
 static void ret2kern_handler(void) {
     /* clang-format off */
@@ -160,6 +162,8 @@ void init_traps(unsigned int cpu) {
                   _ul(asm_interrupt_handler_uart), GATE_DPL0, GATE_PRESENT, 0);
     set_intr_gate(&percpu->idt[PIT_IRQ0_OFFSET], __KERN_CS,
                   _ul(asm_interrupt_handler_pit), GATE_DPL0, GATE_PRESENT, 0);
+    set_intr_gate(&percpu->idt[KEYBOARD_IRQ0_OFFSET], __KERN_CS,
+                  _ul(asm_interrupt_handler_keyboard), GATE_DPL0, GATE_PRESENT, 0);
 
     barrier();
     lidt(&percpu->idt_ptr);

common/kernel.c

@@ -23,6 +23,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <console.h>
+#include <drivers/keyboard.h>
 #include <ktf.h>
 #include <lib.h>
 #include <multiboot.h>
@@ -40,6 +41,13 @@ int usermode_call(user_func_t fn, void *fn_arg) {
                              PERCPU_OFFSET(user_stack));
 }
 
+static void echo_loop(void) {
+    while (1) {
+        io_delay();
+        keyboard_process_keys();
+    }
+}
+
 void kernel_main(void) {
     printk("\nKTF - Kernel Test Framework!\n\n");
 

common/setup.c

@@ -28,6 +28,7 @@
 #include <console.h>
 #include <cpuid.h>
 #include <ioapic.h>
+#include <drivers/keyboard.h>
 #include <ktf.h>
 #include <lib.h>
 #include <multiboot.h>
@@ -235,6 +236,9 @@ void __noreturn __text_init kernel_start(uint32_t multiboot_magic,
     /* Initialize Programmable Interrupt Timer */
     init_pit(get_bsp_cpu_id());
 
+    /* Initialize keyboard */
+    init_keyboard();
+
     /* Jump from .text.init section to .text */
     asm volatile("push %0; ret" ::"r"(&kernel_main));
 

drivers/keyboard.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <drivers/keyboard.h>
+#include <drivers/pic.h>
+#include <lib.h>
+#include <string.h>
+
+static struct {
+    int shift, caps, ctrl, alt;
+
+    char buf[KEY_BUF];
+    unsigned curr;
+    unsigned init;
+} keyboard_state;
+
+void init_keyboard(void) {
+    outb(PIC1_PORT_DATA, KEYBOARD_IRQ_UNMASK); /* unmask keyboard irq */
+
+    memset(&keyboard_state, 0, sizeof(keyboard_state));
+}
+
+static char keyboard_scan_to_key(char scan) {
+    if ((unsigned long) scan < sizeof(key_map)) {
+        unsigned char key = key_map[(unsigned) scan];
+
+        if (key >= 'a' && key <= 'z')
+            return key + ('A' - 'a') * (keyboard_state.caps ^ keyboard_state.shift);
+        else if (keyboard_state.shift && (unsigned long) scan < sizeof(key_map_up))
+            return key_map_up[(unsigned) scan];
+
+        return key;
+    }
+
+    return scan;
+}
+
+unsigned int keyboard_process_keys(void) {
+    unsigned n = 0;
+    unsigned char key, scan;
+
+    while (keyboard_state.curr != keyboard_state.init) {
+        scan = keyboard_state.buf[keyboard_state.init];
+
+        key = keyboard_scan_to_key(scan);
+
+        if (isprint(key))
+            printk("%c", key);
+
+        keyboard_state.init = (keyboard_state.init + 1) % KEY_BUF;
+        ++n;
+    }
+    return n;
+}
+
+void keyboard_interrupt_handler(void) {
+    unsigned char status;
+    int released;
+
+    status = inb(KEYBOARD_PORT_CMD);
+    if (status & KEYBOARD_STATUS_OUT_FULL) {
+        char scan = inb(KEYBOARD_PORT_DATA);
+
+        released = !!(scan & SCAN_RELEASE_MASK);
+        scan = scan & (SCAN_RELEASE_MASK - 1);
+
+        switch (scan) {
+        case SCAN_LSHIFT:
+        case SCAN_RSHIFT:
+            keyboard_state.shift = !released;
+            break;
+        case SCAN_CAPS:
+            if (!released)
+                keyboard_state.caps = !keyboard_state.caps;
+            break;
+        case SCAN_CTRL:
+            keyboard_state.ctrl = !released;
+            break;
+        case SCAN_ALT:
+            keyboard_state.alt = !released;
+            break;
+        default:
+            if (!released) {
+                if ((long unsigned) scan < sizeof(key_map)) {
+                    keyboard_state.buf[keyboard_state.curr] = scan;
+                    keyboard_state.curr = (keyboard_state.curr + 1) % KEY_BUF;
+                }
+                break;
+            }
+        }
+    }
+
+    outb(PIC1_PORT_CMD, PIC_EOI);
+}

drivers/pic.c

@@ -33,8 +33,8 @@ static inline void pic_outb(io_port_t port, unsigned char value) {
 
 void init_pic(void) {
     /* Cascade mode initialization sequence */
-    pic_outb(PIC1_PORT_CMD, PIC_ICW1_INIT | PIC_ICW1_ICW4);
-    pic_outb(PIC2_PORT_CMD, PIC_ICW1_INIT | PIC_ICW1_ICW4);
+    pic_outb(PIC1_PORT_CMD, PIC_ICW1_INIT | PIC_ICW1_LEVEL | PIC_ICW1_ICW4);
+    pic_outb(PIC2_PORT_CMD, PIC_ICW1_INIT | PIC_ICW1_LEVEL | PIC_ICW1_ICW4);
 
     /* Remap PICs interrupt vectors */
     pic_outb(PIC1_PORT_DATA, PIC_IRQ0_OFFSET);
@@ -44,9 +44,9 @@ void init_pic(void) {
     outb(PIC1_PORT_DATA, PIC_CASCADE_PIC1_IRQ);
     outb(PIC2_PORT_DATA, PIC_CASCADE_PIC2_IRQ);
 
-    /* PIC mode: 80x86, Automatic EOI */
-    outb(PIC1_PORT_DATA, PIC_ICW4_8086 | PIC_ICW4_AUTO);
-    outb(PIC2_PORT_DATA, PIC_ICW4_8086 | PIC_ICW4_AUTO);
+    /* PIC mode: 80x86 */
+    outb(PIC1_PORT_DATA, PIC_ICW4_8086);
+    outb(PIC2_PORT_DATA, PIC_ICW4_8086);
 
     /* Mask the 8259A PICs by setting all IMR bits */
     outb(PIC1_PORT_DATA, 0xFF);

include/drivers/keyboard.h

@@ -0,0 +1,103 @@
+/*
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef KTF_KEYBOARD_H
+#define KTF_KEYBOARD_H
+
+#include <drivers/pic.h>
+
+#define KEYBOARD_PORT_CMD  0x64 /* keyboard command port */
+#define KEYBOARD_PORT_DATA 0x60 /* keyboard data port */
+
+#define KEYBOARD_IRQ0_OFFSET (PIC_IRQ0_OFFSET + 1) /* keyboard irq offset */
+#define KEYBOARD_IRQ_UNMASK  (~2) /* mask with keyboard irq enabled, others disabled */
+
+#define KEYBOARD_STATUS_OUT_FULL 1 /* bit set when the keyboard buffer is full */
+
+#define KEY_BUF 80 /* size of internal input buffer */
+
+#define SCAN_RELEASE_MASK 0x80 /* bit set on key release */
+
+#define KEY_NULL 0x0 /* no key */
+
+/* scan codes */
+#define SCAN_NULL       0x0
+#define SCAN_ESC        0x1
+#define SCAN_ENTER      0x1c
+#define SCAN_CTRL       0x1d
+#define SCAN_LSHIFT     0x2a
+#define SCAN_RSHIFT     0x36
+#define SCAN_ALT        0x38
+#define SCAN_CAPS       0x3a
+#define SCAN_F1         0x3b
+#define SCAN_F2         0x3c
+#define SCAN_F3         0x3d
+#define SCAN_F4         0x3e
+#define SCAN_F5         0x3f
+#define SCAN_F6         0x40
+#define SCAN_F7         0x41
+#define SCAN_F8         0x42
+#define SCAN_F9         0x43
+#define SCAN_F10        0x44
+#define SCAN_F11        0x55
+#define SCAN_F12        0x58
+#define SCAN_NUMLOCK    0x45
+#define SCAN_SCROLLLOCK 0x46
+#define SCAN_HOME       0x47
+#define SCAN_UP         0x48
+#define SCAN_PAGEUP     0x49
+#define SCAN_LEFT       0x4b
+#define SCAN_KEYPAD5    0x4c
+#define SCAN_RIGHT      0x4d
+#define SCAN_END        0x4f
+#define SCAN_DOWN       0x50
+#define SCAN_PAGEDOWN   0x51
+#define SCAN_INS        0x52
+#define SCAN_DEL        0x53
+
+void init_keyboard(void);
+void keyboard_interrupt_handler(void);
+unsigned int keyboard_process_keys(void);
+
+/* clang-format off */
+static const unsigned char key_map[] = { /* map scan code to key */
+    0xff,        SCAN_ESC,  '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=',
+    '\b',        '\t',      'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']',
+    SCAN_ENTER,  SCAN_CTRL, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', '`',
+    SCAN_LSHIFT, '\\',      'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/',
+    SCAN_RSHIFT, 0x37, SCAN_ALT, ' ', SCAN_CAPS,
+    SCAN_F1, SCAN_F2, SCAN_F3, SCAN_F4, SCAN_F5, SCAN_F6, SCAN_F7, SCAN_F8, SCAN_F9, SCAN_F10,
+    SCAN_NUMLOCK, SCAN_SCROLLLOCK, SCAN_HOME, SCAN_UP, SCAN_PAGEUP, 0x4a, SCAN_LEFT,
+    SCAN_KEYPAD5, SCAN_RIGHT, 0x4e, SCAN_END, SCAN_DOWN, SCAN_PAGEDOWN, SCAN_INS, SCAN_DEL,
+    0x54, SCAN_F11, 0x56, 0x57, SCAN_F12
+};
+
+static const unsigned char key_map_up[] = { /* map scan code to upper key */
+    0xff,        SCAN_ESC,  '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+',
+    '\b',        '\t',      'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}',
+    SCAN_ENTER,  SCAN_CTRL, 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~',
+    SCAN_LSHIFT, '|',       'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?'};
+/* clang-format on */
+
+#endif

include/string.h

@@ -47,6 +47,8 @@ static inline int isupper(int c) { return c >= 'A' && c <= 'Z'; }
 
 static inline int isalpha(int c) { return islower(c) || isupper(c); }
 
+static inline int isprint(char c) { return c >= 0x20 && c <= 0x7e; }
+
 static inline size_t strlen(const char *str) {
     size_t len = 0;