Attempting to fix gdt, isr, idt and memory.c.

build/CMakeFiles/ClassicOS.dir/C.includecache

@@ -6,25 +6,29 @@
 
 #IncludeRegexTransform: 
 
-/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/drivers/keyboard/keyboard.c
+/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/drivers/screen/screen.c
-stdint.h
+screen.h
--
+/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/drivers/screen/screen.h
 stdbool.h
 -
 stddef.h
 -
-
+stdint.h
-/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/drivers/screen/screen.c
+-
-screen.h
+stdio.h
-/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/drivers/screen/screen.h
+-
-dos.h
+stdlib.h
 -
 
 /media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/drivers/screen/screen.h
-
+stdbool.h
-/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/kernel/kernel.c
+-
-kernel.h
+stddef.h
-/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/kernel/kernel.h
+-
-
+stdint.h
-/media/gbowne1/18656299-5992-400a-a7a4-b6ffc4b0612f/Documents/ClassicOS/src/kernel/kernel.h
+-
+stdio.h
+-
+stdlib.h
+-
 

build/CMakeFiles/Progress/2

@@ -1 +0,0 @@
-empty

src/kernel/arch/x86/gdt.c

@@ -1,22 +1,16 @@
 #include "gdt.h"
 #include "isr.h"
+#include <inttypes.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <inttypes.h>
 
 // GDT table
 struct gdt_entry *gdt;
 
-// GDT pointer
-struct gdt_ptr {
-    uint16_t limit;
-    void* base;
-} gp;
-
 // Initialize a GDT entry
 void gdt_set_gate(uint32_t num, uint32_t base, uint32_t limit, uint8_t access,
                   uint8_t gran)
@@ -30,13 +24,12 @@ void gdt_set_gate(uint32_t num, uint32_t base, uint32_t limit, uint8_t access,
     gdt[num].access = access;
 }
 
-// Initialize the GDT
 void gdt_init()
 {
     // Set up GDT pointer
     gp.limit = (sizeof(struct gdt_entry) * 3) - 1;
     gdt      = (struct gdt_entry *)malloc(sizeof(struct gdt_entry) * 3);
-    gp.base  = gdt;
+    gp.base  = (uint32_t)gdt; // Cast gdt to uint32_t
 
     // Clear GDT
     memset(gdt, 0, sizeof(struct gdt_entry) * 3);

src/kernel/arch/x86/idt.c

@@ -1,22 +1,15 @@
 #include "idt.h"
-#include <string.h>
-
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 // IDT table
 struct idt_entry idt[256];
 
 // IDT pointer
-struct idt_ptr
-{
-    uint16_t          limit; // Size of IDT in bytes - 1
-    struct idt_entry *base;  // Address of IDT
-} __attribute__((packed));
-
 struct idt_ptr idtp;
 
 // Exception handlers
@@ -32,10 +25,11 @@ extern void keyboard_handler();
 extern void device_handler();
 
 // Initialize an IDT entry
-void idt_set_gate(uint8_t num, uint32_t base, uint16_t sel, uint8_t flags)
+void idt_set_gate(uint8_t num, void *base, uint16_t sel, uint8_t flags)
 {
-    idt[num].base_lo = base & 0xFFFF;
+    uint32_t base_addr = (uint32_t)base;
-    idt[num].base_hi = (base >> 16) & 0xFFFF;
+    idt[num].base_lo   = base_addr & 0xFFFF;
+    idt[num].base_hi   = (base_addr >> 16) & 0xFFFF;
     idt[num].sel       = sel;
     idt[num].always0   = 0;
     idt[num].flags     = flags;
@@ -46,23 +40,23 @@ void idt_init()
 {
     // Set up IDT pointer
     idtp.limit = sizeof(idt) - 1;
-    idtp.base  = idt;
+    idtp.base  = &idt[0];
 
     // Clear IDT
     memset(&idt, 0, sizeof(idt));
 
     // Set up exception handlers
-    idt_set_gate(0, (uint32_t)divide_error_handler, 0x08, 0x8E);
+    idt_set_gate(0, divide_error_handler, 0x08, 0x8E);
-    idt_set_gate(14, (uint32_t)page_fault_handler, 0x08, 0x8E);
+    idt_set_gate(14, page_fault_handler, 0x08, 0x8E);
-    idt_set_gate(13, (uint32_t)general_protection_fault_handler, 0x08, 0x8E);
+    idt_set_gate(13, general_protection_fault_handler, 0x08, 0x8E);
-    idt_set_gate(8, (uint32_t)double_fault_handler, 0x08, 0x8E);
+    idt_set_gate(8, double_fault_handler, 0x08, 0x8E);
 
     // Set up interrupt handlers
-    idt_set_gate(0x80, (uint32_t)system_call_handler, 0x08, 0xEE);
+    idt_set_gate(0x80, system_call_handler, 0x08, 0xEE);
-    idt_set_gate(0x20, (uint32_t)timer_handler, 0x08, 0x8E);
+    idt_set_gate(0x20, timer_handler, 0x08, 0x8E);
-    idt_set_gate(0x21, (uint32_t)keyboard_handler, 0x08, 0x8E);
+    idt_set_gate(0x21, keyboard_handler, 0x08, 0x8E);
-    idt_set_gate(0x30, (uint32_t)device_handler, 0x08, 0x8E);
+    idt_set_gate(0x30, device_handler, 0x08, 0x8E);
 
     // Load IDT
-    _asm volatile("lidt %0" : : "m"(idtp));
+    __asm__ volatile("lidt %0" : : "m"(idtp));
 }

src/kernel/arch/x86/idt.h

@@ -4,7 +4,8 @@
 #include <stdint.h>
 
 // IDT entry structure
-struct idt_entry {
+struct idt_entry
+{
     uint16_t base_lo; // Lower 16 bits of handler function address
     uint16_t sel;     // Kernel segment selector
     uint8_t  always0; // Always 0
@@ -13,9 +14,10 @@ struct idt_entry {
 } __attribute__((packed));
 
 // IDT pointer structure
-struct idt_ptr {
+struct idt_ptr
+{
     uint16_t          limit; // Size of IDT in bytes - 1
-    uint32_t base;      // Address of IDT
+    struct idt_entry *base;  // Address of IDT
 } __attribute__((packed));
 
 // Exception handlers
@@ -33,4 +35,4 @@ void device();
 // Initialize the IDT
 void idt_init();
 
-#endif
+#endif /* IDT_H */

src/kernel/arch/x86/isr.c

@@ -1,4 +1,6 @@
 #include "isr.h"
+#include "idt.h"
+#include <stdio.h>
 
 // ISR table
 void (*isr_table[256])(struct isr_regs *regs);
@@ -11,6 +13,12 @@ void isr_register(uint8_t num, void (*handler)(struct isr_regs *regs))
 
 // ISR handler
 void isr_handler(struct isr_regs *regs)
+{
+    if (regs->int_no == 0)
+    {
+        divide_error();
+    }
+    else
     {
         void (*handler)(struct isr_regs *regs);
 
@@ -20,11 +28,12 @@ void isr_handler(struct isr_regs *regs)
             handler(regs);
         }
     }
+}
 
 // Exception handlers
 void divide_error()
 {
-    // Handle divide error exception
+    printf("Divide by zero error!\n");
 }
 
 void page_fault()

src/kernel/arch/x86/memory/memory.c

@@ -46,7 +46,12 @@ void kfree(void *ptr)
     if ((uint8_t *)ptr >= heap_start && ptr < (void *)heap_end)
     {
         /* Zero out the memory */
-        memset(ptr, 0, (uint8_t *)heap_pos - (uint8_t *)ptr);
+        volatile uint8_t *volatile_ptr = (volatile uint8_t *)ptr;
+        size_t            size         = (uint8_t *)heap_pos - (uint8_t *)ptr;
+        while (size--)
+        {
+            *volatile_ptr++ = 0;
+        }
 
         /* Free the memory by moving the heap position */
         heap_pos = (uint8_t *)ptr;