Interrupts + basic keyboard driver

4 files changed, 123 insertions, 0 deletions

diff --git a/src/kernel/keyboard/compile_flags.txt b/src/kernel/keyboard/compile_flags.txt
new file mode 100644
index 0000000..2af49c7
--- /dev/null
+++ b/src/kernel/keyboard/compile_flags.txt
@@ -0,0 +1 @@
+-I../../include/
diff --git a/src/kernel/keyboard/isr.c b/src/kernel/keyboard/isr.c
new file mode 100644
index 0000000..223bf9f
--- /dev/null
+++ b/src/kernel/keyboard/isr.c
@@ -0,0 +1,49 @@
+#include "asm.h"
+#include "print.h"
+#include "str.h"
+#include <stdint.h>
+static uint8_t shift_held = 0;
+static uint8_t capslock = 0;
+
+void keyboard_handler() {
+    const char *scancodes =
+        "??1234567890-=?\tqwertyuiop[]\n?asdfghjkl;'`?\\zxcvbnm,./?*? ";
+    const char *SCANCODES =
+        "\?\?!@#$%^&*()_+?\tQWERTYUIOP{}\n?ASDFGHJKL:\"~?|ZXCVBNM<>??*? ";
+
+    unsigned char sc = inb(0x60);
+
+    uint8_t isheld = shift_held != 0;
+    char c = ((isheld | capslock) & !(isheld & capslock)) ? SCANCODES[sc]
+                                                          : scancodes[sc];
+
+    if (capslock & (!isheld) && !isalpha(c))
+        c = scancodes[sc];
+    if (isheld && !isalpha(c))
+        c = SCANCODES[sc];
+
+    if (sc < 0x59 && scancodes[sc] != '?')
+        printf("%c", c);
+
+    switch (sc) {
+    case 0x2A:
+        shift_held |= 0b10;
+        break;
+    case 0x36:
+        shift_held |= 0b01;
+        break;
+    case 0xAA:
+        shift_held &= 0b01;
+        break;
+    case 0xB6:
+        shift_held &= 0b10;
+        break;
+    case 0x0E:
+        delete_char();
+        break;
+    case 0x3A:
+        capslock = !capslock;
+        break;
+    }
+    outb(0x20, 0x20);
+}
diff --git a/src/kernel/keyboard/isr_wrap.s b/src/kernel/keyboard/isr_wrap.s
new file mode 100644
index 0000000..6f6c58b
--- /dev/null
+++ b/src/kernel/keyboard/isr_wrap.s
@@ -0,0 +1,8 @@
+extern keyboard_handler
+extern wrap_keyboard_handler
+wrap_keyboard_handler:
+    pushad
+    cld
+    call keyboard_handler
+    popad
+    iret
diff --git a/src/kernel/keyboard/pic.c b/src/kernel/keyboard/pic.c
index 0c81629..e1b4fb3 100644
--- a/src/kernel/keyboard/pic.c
+++ b/src/kernel/keyboard/pic.c
@@ -1 +1,66 @@
 #include "asm.h"
+#include <stdint.h>
+#define PIC1 0x20
+#define PIC2 0xA0
+#define PIC1_COMMAND PIC1
+#define PIC1_DATA (PIC1 + 1)
+#define PIC2_COMMAND PIC2
+#define PIC2_DATA (PIC2 + 1)
+
+void PIC_init(int offset1, int offset2) {
+    uint8_t a1, a2;
+
+    a1 = inb(PIC1_DATA);
+    a2 = inb(PIC2_DATA);
+
+    outb(PIC1_COMMAND, 0x11); // Init PIC1
+    io_wait();
+    outb(PIC2_COMMAND, 0x11); // Init PIC2
+    io_wait();
+    outb(PIC1_DATA, offset1); // ICW2: Master PIC vector offset
+    io_wait();
+    outb(PIC2_DATA, offset2); // ICW2: Slave PIC vector offset
+    io_wait();
+    outb(PIC1_DATA, 4);
+    io_wait();
+    outb(PIC2_DATA, 2);
+    io_wait();
+    outb(PIC1_DATA, 0x01);
+    io_wait();
+    outb(PIC2_DATA, 0x01);
+    io_wait();
+
+    outb(PIC1_DATA, a1); // restore saved masks.
+    outb(PIC2_DATA, a2);
+}
+
+void IRQ_mask(uint8_t line) {
+    uint16_t port = line < 8 ? PIC1_DATA : PIC2_DATA;
+    line = line > 8 ? line - 8 : line;
+    uint8_t val = inb(port) | (1 << line);
+    outb(port, val);
+}
+
+void IRQ_unmask(uint8_t line) {
+    uint16_t port = line < 8 ? PIC1_DATA : PIC2_DATA;
+    line = line > 8 ? line - 8 : line;
+    uint8_t val = inb(port) & ~(1 << line);
+    outb(port, val);
+}
+
+void PIC_disable(void) {
+    outb(PIC1_DATA, 0xff);
+    outb(PIC2_DATA, 0xff);
+}
+
+uint16_t PIC_irr(void) {
+    outb(PIC1_COMMAND, 0x0a);
+    outb(PIC2_COMMAND, 0x0a);
+    return (inb(PIC2_COMMAND) << 8) | inb(PIC1_COMMAND);
+}
+
+uint16_t PIC_isr(void) {
+    outb(PIC1_COMMAND, 0x0b);
+    outb(PIC2_COMMAND, 0x0b);
+    return (inb(PIC2_COMMAND) << 8) | inb(PIC1_COMMAND);
+}