Fixed some of gdt.c and .h and also idt.h and isr

src/kernel/arch/x86/gdt.c

@@ -1,4 +1,5 @@
 #include "gdt.h"
+#include "idt.h"
 #include "isr.h"
 #include <inttypes.h>
 #include <stdbool.h>
@@ -9,6 +10,14 @@
 #include <string.h>
 #include <sys/cdefs.h>
 
+#define BYTE_MASK    0xFF
+#define PAGE_FAULT   14
+#define DOUBLE_FAULT 8
+#define SYSTEM_CALL  80
+#define TIMER        20
+
+#define ISR_TABLE_SIZE 256
+
 // GDT table
 struct gdt_entry *gdt;
 
@@ -31,11 +40,11 @@ enum GDT_BASE_LIMIT
 
 // Initialize a GDT entry
 void gdt_set_gate(uint32_t num, uint32_t base, uint32_t limit, uint8_t access,
-                  uint8_t gran)
+                  uint8_t gran, struct gdt_entry *const gdt)
 {
     gdt[num].base_low    = (base & GDT_LIMIT_MASK);
-    gdt[num].base_middle = (base >> GDT_BASE_MIDDLE_SHIFT) & 0xFF;
-    gdt[num].base_high   = (base >> GDT_BASE_HIGH_SHIFT) & 0xFF;
+    gdt[num].base_middle = (base >> GDT_BASE_MIDDLE_SHIFT) & BYTE_MASK;
+    gdt[num].base_high   = (base >> GDT_BASE_HIGH_SHIFT) & BYTE_MASK;
     gdt[num].limit_low   = (limit & GDT_LIMIT_MASK);
     gdt[num].granularity =
         (limit >> GDT_GRANULARITY_SHIFT) & GDT_GRANULARITY_MASK;
@@ -50,6 +59,24 @@ void gdt_init()
     gp.limit = (sizeof(struct gdt_entry) * 3) - 1;
     gdt      = (struct gdt_entry *)malloc(sizeof(struct gdt_entry) * 3);
     memset(gdt, 0, sizeof(struct gdt_entry) * 3);
+
+    // Initialize GDT entries
+    gdt_set_gate(0, 0, 0, 0, 0, gdt);                // Null segment
+    gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF, gdt); // Code segment
+    gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF, gdt); // Data segment
+
+    // Load GDT
+    struct gdt_ptr gdtp;
+    gdtp.limit = gp.limit;
+    gdtp.base  = (uint32_t)gdt;
+    __asm__ volatile("lgdt %0" : : "m"(gdtp));
+    __asm__ volatile("mov $0x10, %ax\n\t"
+                     "mov %ax, %ds\n\t"
+                     "mov %ax, %es\n\t"
+                     "mov %ax, %fs\n\t"
+                     "mov %ax, %gs\n\t"
+                     "ljmp $0x08, $next\n\t"
+                     "next:");
 }
 
 // Exception handlers
@@ -65,15 +92,18 @@ extern void keyboard();
 extern void device();
 
 // ISR table
-void (*isr_table[256])(void) = {0};
+void (*isr_table[ISR_TABLE_SIZE])(void) = {0};
 
 // Register an ISR
-void isr_register(uint8_t num, void (*handler)(struct isr_regs *regs));
+void isr_register(uint8_t num, void (*handler)(void))
+{
+    isr_table[num] = handler;
+}
 
 // ISR handler
-void isr_handler(struct idt_regs *regs);
+void isr_handler(struct idt_regs *regs)
 {
-    void (*handler)(void);
+    void (*handler)(void) = isr_table[regs->int_no];
 
     handler = isr_table[regs->int_no];
     if (handler)
@@ -86,20 +116,20 @@ void isr_handler(struct idt_regs *regs);
 void isr_init()
 {
     // Initialize ISR table
-    for (int i = 0; i < 256; i++)
+    for (int i = 0; i < ISR_TABLE_SIZE; i++)
     {
         isr_table[i] = NULL;
     }
 
     // Register exception handlers
     isr_register(0, divide_error);
-    isr_register(14, page_fault);
+    isr_register(PAGE_FAULT, page_fault);
     isr_register(13, general_protection_fault);
-    isr_register(8, double_fault);
+    isr_register(DOUBLE_FAULT, double_fault);
 
     // Register interrupt handlers
-    isr_register(0x80, system_call);
-    isr_register(0x20, timer);
+    isr_register(SYSTEM_CALL, system_call);
+    isr_register(TIMER, timer);
     isr_register(0x21, keyboard);
     isr_register(0x30, device);
 }

src/kernel/arch/x86/gdt.h

@@ -4,16 +4,14 @@
 
 #include <stdint.h>
 
-// GDT table
-extern struct gdt_entry *gdt;
-
 // GDT entry structure
 struct gdt_entry
 {
     uint16_t limit_low;   // The lower 16 bits of the limit
     uint16_t base_low;    // The lower 16 bits of the base
     uint8_t  base_middle; // The next 8 bits of the base
-    uint8_t access;             // Access flags, determine what ring this segment can be used in
+    uint8_t
+        access; // Access flags, determine what ring this segment can be used in
     uint8_t granularity;
     uint8_t base_high; // The last 8 bits of the base
 } __attribute__((packed));
@@ -28,7 +26,4 @@ struct gdt_ptr
 // Initialize the GDT
 void gdt_init();
 
-// Set a GDT entry
-void gdt_set_gate(uint32_t num, uint32_t base, uint32_t limit, uint8_t access, uint8_t gran);
-
 #endif

src/kernel/arch/x86/idt.h

@@ -4,10 +4,6 @@
 #include <stdint.h>
 
 // Define the isr_regs structure
-struct idt_regs
-{
-    // Add the necessary members for your ISR context
-};
 
 // IDT entry structure
 struct idt_entry
@@ -28,12 +24,9 @@ struct idt_ptr
 
 // Exception handlers
 void divide_error();
-void page_fault(struct idt_regs *);
-void general_protection_fault(struct idt_regs *);
 void double_fault();
 
 // Interrupt handlers
-void system_call(struct idt_regs *);
 void timer();
 void keyboard();
 void device();

src/kernel/arch/x86/isr.h

@@ -4,7 +4,7 @@
 #include <stdint.h>
 
 // Structure for storing register values during an ISR
-struct isr_regs
+struct idt_regs
 {
     uint32_t ds; // Data segment selector
     uint32_t edi, esi, ebp, esp, ebx, edx, ecx,
@@ -15,9 +15,6 @@ struct isr_regs
         ss; // Pushed by the processor automatically
 };
 
-// Register an ISR
-void isr_register(uint8_t num, void (*handler)(struct isr_regs *regs));
-
 // ISR handler
 void isr_handler(struct idt_regs *regs);