uhm pretty much fully implemented IRQ stuff, just need to implement proper handlers but will do later (maybe)

src/kernel/arch/i686/basicfunc.asm

@@ -1,11 +1,11 @@
 [bits 32]
 
-global reboot
-reboot:
+global i686_reboot
+i686_reboot:
     XOR         AL, AL
     IN          AL, 0x64
     TEST        AL, 0x02
-    JNZ         reboot
+    JNZ         i686_reboot
 
     MOV         AL, 0xFC
     OUT         0x64, AL

src/kernel/arch/i686/basicfunc.c

@@ -3,4 +3,4 @@
 |Copyright (C) 2024|
 |Tyler McGurrin    |
 \*----------------*/
-#include "basicdri.h"
+#include "basicfunc.h"

src/kernel/arch/i686/basicfunc.h

@@ -5,4 +5,4 @@
 \*----------------*/
 #pragma once
 
-void __attribute__((cdecl)) reboot();
+void __attribute__((cdecl)) i686_reboot();

src/kernel/arch/i686/io.asm

@@ -4,16 +4,16 @@
 ;Tyler McGurrin       ;
 ;/////////////////////;
 
-global outb
-outb:
+global i686_outb
+i686_outb:
     [bits 32]
     mov dx, [esp + 4]
     mov al, [esp + 8]
     out dx, al
     ret
 
-global inb
-inb:
+global i686_inb
+i686_inb:
     [bits 32]
     mov dx, [esp + 4]
     xor eax, eax
@@ -24,3 +24,13 @@ global i686_panic
 i686_panic:
     cli
     hlt
+
+global i686_EnableInterrupts
+i686_EnableInterrupts:
+    sti
+    ret
+
+global i686_DisableInterrupts
+i686_DisableInterrupts:
+    cli
+    ret

src/kernel/arch/i686/io.c

@@ -2,4 +2,12 @@
 |Nanite OS         |
 |Copyright (C) 2024|
 |Tyler McGurrin    |
-\*----------------*/
+\*----------------*/
+#include "io.h"
+
+#define UNUSED_PORT 0x80
+
+void i686_iowait()
+{
+    i686_outb(UNUSED_PORT, 0);
+}

src/kernel/arch/i686/io.h

@@ -7,8 +7,10 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-void __attribute__((cdecl)) outb(uint16_t port, uint8_t value);
-uint8_t __attribute__((cdecl)) inb(uint16_t port);
+void __attribute__((cdecl)) i686_outb(uint16_t port, uint8_t value);
+uint8_t __attribute__((cdecl)) i686_inb(uint16_t port);
+uint8_t __attribute__((cdecl)) i686_EnableInterrupts();
+uint8_t __attribute__((cdecl)) i686_DisableInterrupts();
 
 void i686_iowait();
 void __attribute__((cdecl)) i686_panic();

src/kernel/arch/i686/irq.c

@@ -0,0 +1,48 @@
+/*----------------*\
+|Nanite OS         |
+|Copyright (C) 2024|
+|Tyler McGurrin    |
+\*----------------*/
+#include "irq.h"
+#include "pic.h"
+#include "io.h"
+#include <stddef.h>
+#include <stdio.h>
+
+#define PIC_REMAP_OFFSET        0x20
+
+IRQHandler g_IRQHandlers[16];
+
+void i686_IRQ_Handler(Registers* regs)
+{
+    int irq = regs->interrupt - PIC_REMAP_OFFSET;
+
+    if (g_IRQHandlers[irq] != NULL)
+    {
+        // handle IRQ
+        g_IRQHandlers[irq](regs);
+    }
+    else
+    {
+        printf("Unhandled IRQ %d...\n", irq);
+    }
+
+    i686_PIC_SendEndOfInterrupt(irq);
+}
+
+void i686_IRQ_Initialize()
+{
+    i686_PIC_Configure(PIC_REMAP_OFFSET, PIC_REMAP_OFFSET + 8);
+
+    // register ISR handlers for each of the 16 IRQ lines
+    for (int i = 0; i < 16; i++)
+        i686_ISR_RegisterHandler(PIC_REMAP_OFFSET + i, i686_IRQ_Handler);
+
+    // enable interrupts 
+    i686_EnableInterrupts();
+}
+
+void i686_IRQ_RegisterHandler(int irq, IRQHandler handler)
+{
+    g_IRQHandlers[irq] = handler;
+}

src/kernel/arch/i686/irq.h

@@ -0,0 +1,12 @@
+/*----------------*\
+|Nanite OS         |
+|Copyright (C) 2024|
+|Tyler McGurrin    |
+\*----------------*/
+#pragma once
+#include "isr.h"
+
+typedef void (*IRQHandler)(Registers* regs);
+
+void i686_IRQ_Initialize();
+void i686_IRQ_RegisterHandler(int irq, IRQHandler handler);

src/kernel/arch/i686/isr.c

@@ -72,4 +72,9 @@ void __attribute__((cdecl)) i686_ISR_Handler(Registers* regs) {
         i686_panic();
     }
 
+}
+void i686_ISR_RegisterHandler(int interrupt, ISRHandler handler)
+{
+    g_ISRHandlers[interrupt] = handler;
+    i686_IDT_EnableGate(interrupt);
 }

src/kernel/arch/i686/isr.h

@@ -19,4 +19,4 @@ typedef struct
 typedef void (*ISRHandler)(Registers* regs);
 
 void i686_ISR_Initialize();
-void i686_ISR_RegisterHandler(int interrupt);
+void i686_ISR_RegisterHandler(int interrupt, ISRHandler handler);

src/kernel/arch/i686/pic.c

@@ -0,0 +1,131 @@
+/*----------------*\
+|Nanite OS         |
+|Copyright (C) 2024|
+|Tyler McGurrin    |
+\*----------------*/
+#include "pic.h"
+#include "io.h"
+
+#define PIC1_COMMAND_PORT       0x20
+#define PIC2_COMMAND_PORT       0xA0
+#define PIC1_DATA_PORT          0x21
+#define PIC2_DATA_PORT          0xA1
+
+enum {
+    PIC_ICW1_ICW4           = 0x01,
+    PIC_ICW1_SINGLE         = 0x02,
+    PIC_ICW1_INTERVAL4      = 0x02,
+    PIC_ICW1_LEVEL          = 0x08,
+    PIC_ICW1_INITITALIZE    = 0x10
+} PIC_ICW1;
+
+enum {
+    PIC_ICW4_8086           = 0x1,
+    PIC_ICW4_AUTO_EDI       = 0x2,
+    PIC_ICW4_BUFFER_MASTER  = 0x4,
+    PIC_ICW4_BUFFER_SLAVE   = 0x0,
+    PIC_ICW4_BUFFERRED      = 0x8,
+    PIC_ICW4_SFNM           = 0x10
+} PIC_ICW4;
+
+enum {
+    PIC_CMD_END_OF_INTERRUPT    = 0x20,
+    PIC_CMD_READ_IRR            = 0x0A,
+    PIC_CMD_READ_ISR            = 0x0B
+} PIC_CMD;
+
+void i686_PIC_Configure(uint8_t offsetPic1, uint8_t offsetPic2)
+{
+    // init control word 1
+    i686_outb(PIC1_COMMAND_PORT, PIC_ICW1_ICW4 | PIC_ICW1_INITITALIZE);
+    i686_iowait();
+    i686_outb(PIC2_COMMAND_PORT, PIC_ICW1_ICW4 | PIC_ICW1_INITITALIZE);
+    i686_iowait();
+
+    // init control word 2 
+    i686_outb(PIC1_DATA_PORT, offsetPic1);
+    i686_iowait();
+    i686_outb(PIC2_DATA_PORT, offsetPic2);
+    i686_iowait();
+
+    // init control word 3
+    i686_outb(PIC1_DATA_PORT, PIC_ICW4_BUFFER_MASTER);     // tell PIC 1 it has slave at IRQ 2
+    i686_iowait();
+    i686_outb(PIC2_DATA_PORT, PIC_ICW4_BUFFER_SLAVE);     // tell PIC 2 its cascade ID
+    i686_iowait();
+
+    // init control word 4
+    i686_outb(PIC1_DATA_PORT, PIC_ICW4_8086);
+    i686_iowait();
+    i686_outb(PIC2_DATA_PORT, PIC_ICW4_8086);
+    i686_iowait();
+
+    // clear data registers
+    i686_outb(PIC1_DATA_PORT, 0);
+    i686_iowait();
+    i686_outb(PIC2_DATA_PORT, 0);
+    i686_iowait();
+}
+
+void i686_PIC_Mask(int irq)
+{
+    uint8_t port;
+
+    if (irq < 8)
+    {
+        port = PIC1_DATA_PORT;
+    }
+    else
+    {
+        irq -=8;
+        port = PIC2_DATA_PORT;
+    }
+    uint8_t mask = i686_inb(port);
+    i686_outb(port, mask | (1 << irq));
+}
+
+void i686_PIC_Unmask(int irq)
+{
+    uint8_t port;
+
+    if (irq < 8)
+    {
+        port = PIC1_DATA_PORT;
+    }
+    else
+    {
+        irq -=8;
+        port = PIC2_DATA_PORT;
+    }
+    uint8_t mask = i686_inb(port);
+    i686_outb(port, mask & ~(1 << irq));
+}
+
+void i686_PIC_Disable()
+{
+    i686_outb(PIC1_DATA_PORT, 0xFF);
+    i686_iowait();
+    i686_outb(PIC2_DATA_PORT, 0xFF);
+    i686_iowait();
+}
+
+void i686_PIC_SendEndOfInterrupt(int irq)
+{
+    if (irq >= 8)
+        i686_outb(PIC2_COMMAND_PORT, PIC_CMD_END_OF_INTERRUPT);
+    i686_outb(PIC1_COMMAND_PORT, PIC_CMD_END_OF_INTERRUPT);
+}
+
+uint16_t i686_PIC_ReadIRQRequestRegister()
+{
+    i686_outb(PIC1_COMMAND_PORT, PIC_CMD_READ_IRR);
+    i686_outb(PIC2_COMMAND_PORT, PIC_CMD_READ_IRR);
+    return i686_inb(PIC2_COMMAND_PORT) | (i686_inb(PIC2_COMMAND_PORT) << 8);
+}
+
+uint16_t i686_PIC_ReadInServiceRegister()
+{
+    i686_outb(PIC1_COMMAND_PORT, PIC_CMD_READ_ISR);
+    i686_outb(PIC2_COMMAND_PORT, PIC_CMD_READ_ISR);
+    return i686_inb(PIC2_COMMAND_PORT) | (i686_inb(PIC2_COMMAND_PORT) << 8);
+}

src/kernel/arch/i686/pic.h

@@ -0,0 +1,15 @@
+/*----------------*\
+|Nanite OS         |
+|Copyright (C) 2024|
+|Tyler McGurrin    |
+\*----------------*/
+#pragma once
+
+#include <stdint.h>
+void i686_PIC_Configure(uint8_t offsetPic1, uint8_t offsetPic2);
+void i686_PIC_SendEndOfInterrupt(int irq);
+void i686_PIC_Disable();
+void i686_PIC_Mask(int irq);
+void i686_PIC_Unmask(int irq);
+uint16_t i686_PIC_ReadIRQRequestRegister();
+uint16_t i686_PIC_ReadInServiceRegister();

src/kernel/hal/hal.c

@@ -7,6 +7,7 @@
 #include <arch/i686/gdt.h>
 #include <arch/i686/idt.h>
 #include <arch/i686/isr.h>
+#include <arch/i686/irq.h>
 #include <stdio.h>
 
 void HAL_Initialize() { 
@@ -22,5 +23,9 @@ void HAL_Initialize() {
     printf("> Initializing ISR...");
     i686_ISR_Initialize();
     printf("Done!\n");
+    // init IRQ
+    printf("> Initializing IRQ Handling...");
+    i686_IRQ_Initialize();
+    printf("Done!\n");
 
 }

src/kernel/main.c

@@ -8,13 +8,19 @@
 #include <memory.h>
 #include <hal/hal.h>
 #include <arch/i686/io.h>
-#include <arch/i686/basicdri.h>
+#include <arch/i686/irq.h>
+#include <arch/i686/basicfunc.h>
 #include "../version.h"
 
 extern uint8_t __bss_start;
 extern uint8_t __end;
 
- void __attribute__((section(".entry"))) start(uint16_t bootDrive) {
+void timer(Registers* regs)
+{
+    printf(".");
+}
+
+void __attribute__((section(".entry"))) start(uint16_t bootDrive) {
 
     // print logo
     clrscr();
@@ -26,9 +32,9 @@ extern uint8_t __end;
     printf("Initializing HAL...\n");
     HAL_Initialize();
     movecursorpos(19, 8);
-    printf("Done!\n\n\n\n");
-
+    printf("Done!\n\n\n\n\n");
 
+    i686_IRQ_RegisterHandler(0, timer);
 
 
 end:

src/kernel/stdio.c

@@ -51,10 +51,10 @@ void setcursor(int x, int y)
 {
     int pos = y * SCREEN_WIDTH + x;
 
-    outb(0x3D4, 0x0F);
-    outb(0x3D5, (uint8_t)(pos & 0xFF));
-    outb(0x3D4, 0x0E);
-    outb(0x3D5, (uint8_t)((pos >> 8) & 0xFF));
+    i686_outb(0x3D4, 0x0F);
+    i686_outb(0x3D5, (uint8_t)(pos & 0xFF));
+    i686_outb(0x3D4, 0x0E);
+    i686_outb(0x3D5, (uint8_t)((pos >> 8) & 0xFF));
 }
 
 void clrscr()