From 42fc169e10e518af7bdc3645db5d32f09a8ad070 Mon Sep 17 00:00:00 2001
From: xamidev <xamidev@riseup.net>
Date: Mon, 22 Dec 2025 21:04:45 +0100
Subject: [PATCH] Interrupt Dispatch and Handling (for first common vectors)

---
 src/idt/idt.S   |  2 ++
 src/idt/idt.c   |  3 ++-
 src/idt/idt.h   |  3 +++
 src/io/serial.c |  3 +++
 src/kmain.c     | 20 +++++++++++++++++---
 src/mem/gdt.c   |  3 +++
 6 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/idt/idt.S b/src/idt/idt.S
index 60be323..7adf2bb 100644
--- a/src/idt/idt.S
+++ b/src/idt/idt.S
@@ -40,6 +40,7 @@ interrupt_stub:
     push rdx
     push rsi 
     push rdi
+    push rsp
     push rbp
     push r8
     push r9
@@ -65,6 +66,7 @@ interrupt_stub:
     pop r9
     pop r8
     pop rbp
+    pop rsp
     pop rdi
     pop rsi
     pop rdx
diff --git a/src/idt/idt.c b/src/idt/idt.c
index 21237b5..e13b7ab 100644
--- a/src/idt/idt.c
+++ b/src/idt/idt.c
@@ -44,13 +44,14 @@ void idt_init()
         // Each vector handler is 16-byte aligned, so <vector_no>*16 = address of that handler
         idt_set_entry(i, vector_0_handler + (i*16), 0);
     }
+    idt_load(&idt);
+    serial_kputs("kernel: idt: Initialized IDT!\n");
 }
 
 struct cpu_status_t* interrupt_dispatch(struct cpu_status_t* context)
 {
     switch(context->vector_number)
     {
-        // TODO: add serial logs for all interrupts
         case 0:
             serial_kputs("kernel: idt: Divide Error!\n");
             break;
diff --git a/src/idt/idt.h b/src/idt/idt.h
index 05ae631..37b6e32 100644
--- a/src/idt/idt.h
+++ b/src/idt/idt.h
@@ -3,6 +3,8 @@
 
 #include <stdint.h>
 
+void idt_init();
+
 struct interrupt_descriptor
 {
     uint16_t address_low;
@@ -34,6 +36,7 @@ struct cpu_status_t
     uint64_t r9;
     uint64_t r8;
     uint64_t rbp;
+    uint64_t rsp;
     uint64_t rdi;
     uint64_t rsi;
     uint64_t rdx;
diff --git a/src/io/serial.c b/src/io/serial.c
index 7584dfa..388b5b3 100644
--- a/src/io/serial.c
+++ b/src/io/serial.c
@@ -1,4 +1,5 @@
 #include "../kernel.h"
+#include "serial.h"
 
 void outb(int port, unsigned char data)
 {
@@ -34,6 +35,8 @@ int serial_init()
 
     // Set normal operation mode
     outb(PORT + 4, 0x0F);
+
+    serial_kputs("\n\nkernel: serial: Serial initialization OK!\n");
     return 0;
 }
 
diff --git a/src/kmain.c b/src/kmain.c
index 7a65ab6..9616db4 100644
--- a/src/kmain.c
+++ b/src/kmain.c
@@ -6,6 +6,7 @@
 #include "io/serial.h"
 #include "mem/gdt.h"
 #include "mem/utils.h"
+#include "idt/idt.h"
 
 // Limine version used
 __attribute__((used, section(".limine_requests")))
@@ -35,6 +36,20 @@ static void hcf()
 	}
 }
 
+static inline void trigger_div0(void)
+{
+    asm volatile (
+        "mov $1, %%rax\n"
+        "xor %%rdx, %%rdx\n"
+        "xor %%rcx, %%rcx\n"  // divisor = 0
+        "idiv %%rcx\n"
+        :
+        :
+        : "rax", "rcx", "rdx"
+    );
+}
+
+
 // This is our entry point
 void kmain()
 {
@@ -47,14 +62,13 @@ void kmain()
 	if (term_init()) hcf();
 
 	if (serial_init()) kputs("kernel: serial: error: Cannot init serial communication!");
-	
-	serial_kputs("\n\nkernel: serial: Hello, world from serial!\n");
 
 	gdt_init();
-	serial_kputs("kernel: gdt: Initialized GDT!");
+	idt_init();
 
 	// Draw something
 	printf("%s, %s!", "Hello", "world");
 
+	trigger_div0();
 	hcf();
 }
diff --git a/src/mem/gdt.c b/src/mem/gdt.c
index 133973e..fb82ae7 100644
--- a/src/mem/gdt.c
+++ b/src/mem/gdt.c
@@ -1,5 +1,6 @@
 #include "gdt.h"
 #include <stdint.h>
+#include "../io/serial.h"
 
 // Descriptors are 8-byte wide (64bits)
 // So the selectors will be (in bytes): 0x0, 0x8, 0x10, 0x18, etc..
@@ -76,4 +77,6 @@ void gdt_init()
     // Load the GDT we created, flush the old one
     gdt_load();
     gdt_flush();
+
+    serial_kputs("kernel: gdt: Initialized GDT!\n");
 }
\ No newline at end of file