Interrupts + basic keyboard driver

13 files changed, 260 insertions, 100 deletions

diff --git a/src/kernel/exceptions.c b/src/kernel/exceptions.c
new file mode 100644
index 0000000..ded9e9b
--- /dev/null
+++ b/src/kernel/exceptions.c
@@ -0,0 +1,9 @@
+#include "print.h"
+
+__attribute__((noreturn)) void exception_handler(void);
+void exception_handler() {
+    print_set_color(PRINT_COLOR_RED, PRINT_COLOR_BLACK);
+    print_clear();
+    printf("KERNEL EXCEPTION");
+    __asm__ volatile("cli; hlt");
+}
diff --git a/src/kernel/idt.c b/src/kernel/idt.c
deleted file mode 100644
index 2805889..0000000
--- a/src/kernel/idt.c
+++ /dev/null
@@ -1,23 +0,0 @@
-#include "idt.h"
-#include "gdt.h"
-#include <stdint.h>
-
-static Gate_Descriptor_t idt[256];
-extern GDTR_t idtr;
-
-void get_idtr() {
-    idtr.offset = (uintptr_t)&idt[0];
-    idtr.size = sizeof(Gate_Descriptor_t) * 256 - 1;
-    for (uint8_t vec = 0; vec < 32; vec++) {
-        make_gate(stub_table[vec], 0x8E, vec);
-    }
-}
-
-void make_gate(uint32_t offset, uint8_t attrs, uint8_t vec) {
-    Gate_Descriptor_t *descriptor = &idt[vec];
-
-    descriptor->offset_low = offset & 0xFFFF;
-    descriptor->attrs = (0b1000 << 4) | attrs;
-    descriptor->offset_high = offset >> 16, descriptor->segment_selector = 0x08;
-    descriptor->reserved = 0;
-}
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index b582e85..7dd3deb 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -1,5 +1,9 @@
-#include "kernel.h"
+#include "asm.h"
+#include "gdt.h"
+#include "isr.h"
 #include "print.h"
+extern GDTR_t idtr;
+extern GDTR_t gdtr;
 
 #if defined(__linux__)
 #error "Not using cross compiler!"
@@ -10,49 +14,20 @@
 #error "Must use ix86-elf compiler"
 #endif
 
-void motd() {
-    char *empty_row = "                                                        "
-                      "                        \n";
-    empty_row[0] = (char)186;
-    empty_row[79] = (char)186;
-
-    printf("%c", 201);
-    for (int i = 0; i < 78; i++)
-        printf("%c", 205);
-    printf("%c\n", 187);
-
-    printf(empty_row);
-
-    printf("%c", 186);
-    for (int i = 0; i < 78 / 2 - 17 / 2; i++)
-        printf(" ");
-    printf("Welcome to gftos!");
-    for (int i = 0; i < 78 / 2 - 17 / 2 - 1; i++)
-        printf(" ");
-    printf("%c\n", 186);
-
-    for (int i = 0; i < 21; i++) {
-        printf(empty_row);
-    }
-
-    printf("%c", 200);
-    for (int i = 0; i < 78; i++)
-        printf("%c", 205);
-    printf("%c", 188);
-}
-
-void kernel_panic(const char *error) {
-    print_set_color(PRINT_COLOR_BLACK, PRINT_COLOR_RED);
-    print_clear();
-    printf(" PANIC! ERROR: %s", error);
-    for (;;)
-        ;
-}
+void motd() { printf("Welcome to gftos!\n=================\n"); }
 
 void kernel_main(void) {
+    PIC_init(0x20, 0xA0);
+    IRQ_mask(0);
+
+    print_set_color(PRINT_COLOR_PINK, PRINT_COLOR_DARK_GRAY);
     print_clear();
     motd();
-    /* kernel_panic("test_panic."); */
+    for (;;) {
+        update_cursor();
+        asm("hlt");
+    }
+
     // for (int r = 0; r < 24; r++) {
     //     for (int c = 0; c < 80; c += 3) {
     //         int color = (r + c) % 15 + 1;
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);
+}
diff --git a/src/kernel/print.c b/src/kernel/print.c
index d5e8790..7a54c7b 100644
--- a/src/kernel/print.c
+++ b/src/kernel/print.c
@@ -1,9 +1,12 @@
 #include "print.h"
+#include "asm.h"
 #include "str.h"
 #include <stdarg.h>
+#include <stdint.h>
 // Constants
 static const size_t NUM_COLS = 80;
 static const size_t NUM_ROWS = 25;
+static uint8_t cursor = 0;
 
 // Char struct
 struct Char {
@@ -34,6 +37,18 @@ void clear_row(size_t row) {
     }
 }
 
+void delete_char() {
+    if (col == 0) {
+        row--;
+        col = NUM_COLS;
+    }
+    col--;
+    buffer[col + NUM_COLS * row] = (struct Char){
+        ' ',
+        color,
+    };
+}
+
 // Call clear_row for every row
 void print_clear() {
     for (size_t i = 0; i < NUM_ROWS; i++) {
@@ -62,6 +77,15 @@ void print_newline() {
     clear_row(NUM_ROWS - 1);
 }
 
+void update_cursor() {
+    uint16_t pos = col + NUM_COLS * row;
+
+    outb(0x3D4, 0x0F);
+    outb(0x3D5, (uint8_t)(pos & 0xFF));
+    outb(0x3D4, 0x0E);
+    outb(0x3D5, (uint8_t)((pos >> 8) & 0xFF));
+}
+
 // printchar
 void print_char(char character) {
     // If \n, call newline
@@ -76,7 +100,7 @@ void print_char(char character) {
     }
 
     // if cols is too large, overflow
-    if (col > NUM_COLS) {
+    if (col >= NUM_COLS) {
         print_newline();
     }
 
@@ -105,7 +129,7 @@ void print_set_color(uint8_t foreground, uint8_t background) {
 void printf(const char *str, ...) {
     va_list args;
     va_start(args, str);
-    char temp_str[256];
+    char temp_str[256] = "";
 
     for (size_t i = 0; str[i] != '\0'; ++i) {
         if (str[i] == '%') {
@@ -114,6 +138,10 @@ void printf(const char *str, ...) {
             case 'd':
                 print_str(itoa(va_arg(args, int), temp_str, 10));
                 break;
+            case 'x':
+                print_str("0x");
+                print_str(itoa(va_arg(args, int), temp_str, 16));
+                break;
             case 's':
                 print_str(va_arg(args, char *));
                 break;
diff --git a/src/kernel/stub_table.asm b/src/kernel/stub_table.asm
deleted file mode 100644
index 9901cea..0000000
--- a/src/kernel/stub_table.asm
+++ /dev/null
@@ -1,33 +0,0 @@
-extern exception_handler
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_err_stub    0
-isr_no_err_stub 0
-isr_err_stub    0
-isr_err_stub    0
-isr_err_stub    0
-isr_err_stub    0
-isr_err_stub    0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_err_stub    0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_no_err_stub 0
-isr_err_stub    0
-isr_no_err_stub 0
diff --git a/src/kernel/tables/compile_flags.txt b/src/kernel/tables/compile_flags.txt
new file mode 100644
index 0000000..2af49c7
--- /dev/null
+++ b/src/kernel/tables/compile_flags.txt
@@ -0,0 +1 @@
+-I../../include/
diff --git a/src/kernel/gdt.c b/src/kernel/tables/gdt.c
index 406b40c..9c65152 100644
--- a/src/kernel/gdt.c
+++ b/src/kernel/tables/gdt.c
@@ -4,9 +4,9 @@
 GDT_t table = 0x0;
 extern GDTR_t gdtr;
 void get_gdtr() {
-    uint32_t base = 0x0000;
+    uint32_t base = (uint32_t)table;
 
-    table[0] = make_descriptor(0, 0, 0);
+    table[0] = make_descriptor(base, 0, 0);
     table[1] = make_descriptor(base, 0x3FFFF, make_code(0, 0, 1));
     table[2] = make_descriptor(base, 0x3FFFF, make_data(0, 0, 1));
 
diff --git a/src/kernel/tables/idt.c b/src/kernel/tables/idt.c
new file mode 100644
index 0000000..01a6776
--- /dev/null
+++ b/src/kernel/tables/idt.c
@@ -0,0 +1,27 @@
+#include "idt.h"
+#include "gdt.h"
+#include "isr.h"
+#include <stdint.h>
+
+__attribute__((aligned(0x10))) static Gate_Descriptor_t idt[256];
+extern GDTR_t idtr;
+extern void *isr_stub_table;
+
+void get_idtr() {
+    idtr.offset = (uintptr_t)&idt[0];
+    idtr.size = sizeof(Gate_Descriptor_t) * 256 - 1;
+    for (uint8_t vec = 0; vec < 32; vec++) {
+        make_gate(((void **)(isr_stub_table))[vec], 0x8E, vec);
+    }
+    make_gate(wrap_keyboard_handler, 0x8E, 0x21);
+}
+
+void make_gate(void *isr, uint8_t attrs, uint8_t vec) {
+    Gate_Descriptor_t *descriptor = &idt[vec];
+
+    descriptor->offset_low = (uint32_t)isr & 0xFFFF;
+    descriptor->attrs = (0b1000 << 4) | attrs;
+    descriptor->offset_high = (uint32_t)isr >> 16;
+    descriptor->segment_selector = 0x08;
+    descriptor->reserved = 0;
+}
diff --git a/src/kernel/tables/stub.s b/src/kernel/tables/stub.s
new file mode 100644
index 0000000..11e457a
--- /dev/null
+++ b/src/kernel/tables/stub.s
@@ -0,0 +1,53 @@
+
+%macro isr_err_stub 1
+isr_stub_%+%1:
+    call exception_handler
+    iret
+%endmacro
+%macro isr_no_err_stub 1
+isr_stub_%+%1:
+    call exception_handler
+    iret
+%endmacro
+
+extern exception_handler
+isr_no_err_stub 0
+isr_no_err_stub 1
+isr_no_err_stub 2
+isr_no_err_stub 3
+isr_no_err_stub 4
+isr_no_err_stub 5
+isr_no_err_stub 6
+isr_no_err_stub 7
+isr_err_stub    8
+isr_no_err_stub 9
+isr_err_stub    10
+isr_err_stub    11
+isr_err_stub    12
+isr_err_stub    13
+isr_err_stub    14
+isr_no_err_stub 15
+isr_no_err_stub 16
+isr_err_stub    17
+isr_no_err_stub 18
+isr_no_err_stub 19
+isr_no_err_stub 20
+isr_no_err_stub 21
+isr_no_err_stub 22
+isr_no_err_stub 23
+isr_no_err_stub 24
+isr_no_err_stub 25
+isr_no_err_stub 26
+isr_no_err_stub 27
+isr_no_err_stub 28
+isr_no_err_stub 29
+isr_err_stub    30
+isr_no_err_stub 31
+
+global isr_stub_table
+isr_stub_table:
+%assign i 0
+%rep 32
+    dd isr_stub_%+i
+%assign i i+1
+%endrep