フレームバッファ割り込みの実装

2020-08-29 17:13:36 +09:00
parent 266f9bf4af
commit 6159cb9d27
18 changed files with 1003 additions and 0 deletions
@@ -0,0 +1,122 @@
+#include <Library/BaseLib.h>
+
+#include "io.h"
+#include "text.h"
+#define SPECIAL_SHIFT_L 0b00000001
+#define SPECIAL_SHIFT_R 0b00000010
+#define SPECIAL_CTRL_L 0b00000100
+#define SPECIAL_CTRL_R 0b00001000
+#define SPECIAL_ALT_L 0b00010000
+#define SPECIAL_ALT_R 0b00100000
+#define SPECIAL_SUPER_L 0b01000000
+#define SPECIAL_SUPER_R 0b10000000
+
+void null_handler();
+void kbd_handler();
+IA32_IDT_GATE_DESCRIPTOR descriptors[256];
+
+void descriptor_init() {
+    for (int i = 0; i < 256; i++) {
+        descriptors[i].Bits.Selector = 0x08;
+        descriptors[i].Bits.GateType = IA32_IDT_GATE_TYPE_INTERRUPT_32;
+        descriptors[i].Bits.OffsetLow = (UINT32)(UINTN)(VOID *)null_handler;
+        descriptors[i].Bits.OffsetHigh =
+            (UINT32)((UINTN)(VOID *)null_handler >> 16);
+        descriptors[i].Bits.OffsetUpper =
+            (UINT32)((UINTN)(VOID *)null_handler >> 32);
+    }  // null descriptor set
+}
+
+void set_handler(int num, UINTN handler) {
+    descriptors[num].Bits.OffsetLow = (UINT32)handler;
+    descriptors[num].Bits.OffsetHigh = (UINT32)(handler >> 16);
+    descriptors[num].Bits.OffsetUpper = (UINT32)(handler >> 32);
+}
+
+void master_pic_init() {
+    mapped_io_write(0x0020, 0x11);  // ICW1
+    mapped_io_write(0x0021, 32);    // ICW2
+    mapped_io_write(0x0021, 0x04);  // ICW3
+    mapped_io_write(0x0021, 0x01);  // ICW4
+    mapped_io_write(0x0021, 0xFF);  // OCW1
+}
+
+void slave_pic_init() {
+    mapped_io_write(0x00A0, 0x11);
+    mapped_io_write(0x00A1, 40);
+    mapped_io_write(0x00A1, 0x02);
+    mapped_io_write(0x00A1, 0x01);
+    mapped_io_write(0x00A1, 0xff);
+}
+
+void unmask_interrupt(UINT8 interrupt_num) {
+    if (interrupt_num < 40) {
+        UINT8 mask = mapped_io_read(0x0021);
+        mapped_io_write(0x0021, mask & ~(1 << (interrupt_num - 32)));
+    } else {
+        UINT8 mask = mapped_io_read(0x00A1);
+        mapped_io_write(0x00A1, mask & ~(1 << (interrupt_num - 40)));
+    }
+}
+
+void end_of_interrupt(UINT8 interrupt_num) {
+    if (interrupt_num < 40) {
+        mapped_io_write(0x0020, 0x60 | (interrupt_num - 32));
+    } else {
+        mapped_io_write(0x00A0, 0x60 | (interrupt_num - 40));
+    }
+}
+
+void interrupt_init() {
+    IA32_DESCRIPTOR Descriptor;
+    descriptor_init();
+    set_handler(33, (UINTN)(VOID *)kbd_handler);
+    Descriptor.Limit = (UINT16)(sizeof(descriptors) - 1);
+    Descriptor.Base = (UINT32)(UINTN)(VOID *)descriptors;
+    AsmWriteIdtr(&Descriptor);
+    EnableInterrupts();
+    master_pic_init();
+    slave_pic_init();
+    unmask_interrupt(33);
+}
+
+void keyboard_int_proc() {
+    UINT8 data;
+    // static char keyboard_special_keys = 0;
+    data = mapped_io_read(0x64);
+    if ((data & 0b00000001) == 0)  // output buffer is not full
+        goto eoi;
+    data = mapped_io_read(0x60);
+    /*
+    if (data & 0b10000000){  // key is broken
+        switch (data & 0b01111111) {
+            case 44:
+                keyboard_special_keys &= ~SPECIAL_SHIFT_L;
+                return;
+            case 57:
+                keyboard_special_keys &= ~SPECIAL_SHIFT_R;
+                return;
+            case 58:
+                keyboard_special_keys &= ~SPECIAL_CTRL_L;
+                return;
+            case 64:
+                keyboard_special_keys &= ~SPECIAL_CTRL_R;
+                return;
+            case 60:
+                keyboard_special_keys &= ~SPECIAL_ALT_L;
+                return;
+            case 62:
+                keyboard_special_keys &= ~SPECIAL_ALT_R;
+                return;
+            case :
+                keyboard_special_keys &= ~SPECIAL_CTRL_L;
+                return;
+            default:
+                return;
+        }
+    }
+    */
+    textout('0');
+eoi:
+    end_of_interrupt(33);
+}