From 507bdb2bc255e095bfe4c1580178db3483b5d9a7 Mon Sep 17 00:00:00 2001
From: Ox03bb <ali.de.bouakaz@gmail.com>
Date: Wed, 9 Sep 2026 01:52:19 +0100
Subject: [PATCH 1/6] add pit driver

---
 includes/{ => interrupt}/pic.h |  0
 includes/interrupt/pit.h       | 14 +++++++
 src/interrupt/irq.asm          | 77 +++++++++++++++++-----------------
 src/interrupt/irq.c            |  5 +++
 src/interrupt/pit.c            | 35 ++++++++++++++++
 src/kernel/kernel.c            | 14 +++++--
 6 files changed, 103 insertions(+), 42 deletions(-)
 rename includes/{ => interrupt}/pic.h (100%)
 create mode 100644 includes/interrupt/pit.h
 create mode 100644 src/interrupt/pit.c

diff --git a/includes/pic.h b/includes/interrupt/pic.h
similarity index 100%
rename from includes/pic.h
rename to includes/interrupt/pic.h
diff --git a/includes/interrupt/pit.h b/includes/interrupt/pit.h
new file mode 100644
index 0000000..ab61170
--- /dev/null
+++ b/includes/interrupt/pit.h
@@ -0,0 +1,14 @@
+#ifndef PIT_H
+#define PIT_H
+
+#define PIT_CHANNEL0  0x40
+#define PIT_COMMAND   0x43
+#define PIT_BASE_FREQ 1193182
+
+#include <stdint.h>
+
+void pit_init(uint32_t frequency);
+void pit_set_frequency(uint32_t frequency);
+uint16_t pit_calculate_divisor(uint32_t frequency);
+
+#endif
\ No newline at end of file
diff --git a/src/interrupt/irq.asm b/src/interrupt/irq.asm
index f34115f..9548965 100644
--- a/src/interrupt/irq.asm
+++ b/src/interrupt/irq.asm
@@ -1,23 +1,5 @@
-; ============================================================
-; IRQ handlers 0-15
-;
-; PIC IRQs:
-;   IRQ 0  -> IDT vector 32
-;   IRQ 1  -> IDT vector 33
-;   ...
-;   IRQ 15 -> IDT vector 47
-;
-; The IDT uses vectors 32-47, but we pass IRQ numbers
-; 0-15 to the C IRQ handler.
-; ============================================================
-
 [BITS 32]
 
-
-; ============================================================
-; Export IRQ handlers and IRQ table
-; ============================================================
-
 global irq0
 global irq1
 global irq2
@@ -37,31 +19,33 @@ global irq15
 
 global irq_table
 
-
 extern irq_handler
 
 
 ; ============================================================
 ; IRQ macro
 ;
-; IRQs do NOT automatically push an error code.
+; Hardware IRQs do NOT automatically push an error code.
 ;
-; We push:
+; We push only the IRQ number ourselves.
 ;
-;   1. dummy error code
-;   2. IRQ number
+; Stack when entering irq_common_stub:
 ;
-; This gives us a predictable stack layout.
+;   [ESP]     = IRQ number
+;   [ESP + 4] = EIP
+;   [ESP + 8] = CS
+;   [ESP + 12] = EFLAGS
 ; ============================================================
 
 %macro IRQ 1
 
 irq%1:
-
+    ; Interrupt gates already clear IF automatically.
+    ; This CLI is therefore optional.
     cli
 
-    push dword 0        ; dummy error code
-    push dword %1       ; IRQ number: 0-15
+    ; Push IRQ number
+    push dword %1
 
     jmp irq_common_stub
 
@@ -69,7 +53,7 @@ irq%1:
 
 
 ; ============================================================
-; IRQ entry points
+; IRQ handlers
 ; ============================================================
 
 IRQ 0
@@ -121,29 +105,44 @@ irq_table:
 
 
 ; ============================================================
-; Common IRQ stub
+; Common IRQ handler
 ; ============================================================
 
 section .text
 
 irq_common_stub:
 
-    ; Save general-purpose registers
+    ; Save all general-purpose registers
     pusha
 
-    ; Pass pointer to interrupt frame
-    push esp
+    ; After PUSHA:
+    ;
+    ; [ESP + 0]  = EDI
+    ; [ESP + 4]  = ESI
+    ; [ESP + 8]  = EBP
+    ; [ESP + 12] = original ESP
+    ; [ESP + 16] = EBX
+    ; [ESP + 20] = EDX
+    ; [ESP + 24] = ECX
+    ; [ESP + 28] = EAX
+    ; [ESP + 32] = IRQ number
+    ; [ESP + 36] = EIP
+    ; [ESP + 40] = CS
+    ; [ESP + 44] = EFLAGS
+
+    ; Pass IRQ number to C
+    push dword [esp + 32]
+
     call irq_handler
+
+    ; Remove argument passed to C
     add esp, 4
 
-    ; Restore general-purpose registers
+    ; Restore registers
     popa
 
-    ; Remove:
-    ;
-    ;   4 bytes = IRQ number
-    ;   4 bytes = dummy error code
-    ;
-    add esp, 8
+    ; Remove IRQ number
+    add esp, 4
 
+    ; Return from interrupt
     iretd
\ No newline at end of file
diff --git a/src/interrupt/irq.c b/src/interrupt/irq.c
index 84a97a4..31ec781 100644
--- a/src/interrupt/irq.c
+++ b/src/interrupt/irq.c
@@ -1,9 +1,14 @@
 #include "irq.h"
 #include "vga.h"
 #include "vga_lib.h"
+#include "pic.h"
 
 void irq_handler(uint32_t vector) {
+
     vga_print("IRQ: ");
     vga_print_hex(vector);
     vga_print("\n");
+
+    pic_send_eoi((uint8_t)vector);
+
 }
\ No newline at end of file
diff --git a/src/interrupt/pit.c b/src/interrupt/pit.c
new file mode 100644
index 0000000..10738f7
--- /dev/null
+++ b/src/interrupt/pit.c
@@ -0,0 +1,35 @@
+#include "pit.h"
+#include "utils.h"
+#include <stdint.h>
+
+void pit_init(uint32_t frequency){
+    pit_set_frequency(frequency);
+}
+
+
+void pit_set_frequency(uint32_t frequency){
+    uint16_t divisor = pit_calculate_divisor(frequency);
+
+    outb(PIT_COMMAND, 0x34); // ch 0, mode 2, binary
+
+    outb(PIT_CHANNEL0, (uint8_t)(divisor & 0xFF));        // Low byte
+    outb(PIT_CHANNEL0, (uint8_t)((divisor >> 8) & 0xFF)); // High byte
+
+}
+
+
+uint16_t pit_calculate_divisor(uint32_t frequency)
+{
+    if (frequency == 0)
+        return 0;
+
+    uint32_t divisor = PIT_BASE_FREQ / frequency;
+
+    if (divisor < 1)
+        divisor = 1;
+
+    if (divisor > 65535) // overflow check
+        divisor = 65535;
+
+    return (uint16_t)divisor;
+}
\ No newline at end of file
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index 446dac9..72fd6a3 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -2,6 +2,7 @@
 #include "idt.h"
 #include "panic.h"
 #include "pic.h"
+#include "pit.h"
 #include "utils.h"
 #include "vga.h"
 #include "vga_lib.h"
@@ -20,12 +21,19 @@ void kernel_main() {
     idt_init();
     vga_print_at_end_c("... Ok\n", GREEN);
 
-    asm volatile("int $0x22");
+    vga_log_info("[", "init", "] pit");
+    pic_clear_mask(0);
+    pit_init(100); // 100 Hz
+    vga_print_at_end_c("... Ok\n", GREEN);
+
+    // asm volatile("int $0x22");
+
+    // panic("testing panics");
 
-    panic("testing panics");
+    asm volatile("sti");
 
     for (;;) {
-        asm volatile("cli");
+        asm volatile("hlt");
     }
 
     return;

From dc3dc6341127aae65ef68837c34ed45029d0097e Mon Sep 17 00:00:00 2001
From: Ox03bb <ali.de.bouakaz@gmail.com>
Date: Wed, 9 Sep 2026 01:58:06 +0100
Subject: [PATCH 2/6] update folder structer

---
 src/interrupt/{ => irq}/irq.asm | 0
 src/interrupt/{ => irq}/irq.c   | 0
 src/interrupt/{ => isr}/isr.asm | 0
 src/interrupt/{ => isr}/isr.c   | 0
 4 files changed, 0 insertions(+), 0 deletions(-)
 rename src/interrupt/{ => irq}/irq.asm (100%)
 rename src/interrupt/{ => irq}/irq.c (100%)
 rename src/interrupt/{ => isr}/isr.asm (100%)
 rename src/interrupt/{ => isr}/isr.c (100%)

diff --git a/src/interrupt/irq.asm b/src/interrupt/irq/irq.asm
similarity index 100%
rename from src/interrupt/irq.asm
rename to src/interrupt/irq/irq.asm
diff --git a/src/interrupt/irq.c b/src/interrupt/irq/irq.c
similarity index 100%
rename from src/interrupt/irq.c
rename to src/interrupt/irq/irq.c
diff --git a/src/interrupt/isr.asm b/src/interrupt/isr/isr.asm
similarity index 100%
rename from src/interrupt/isr.asm
rename to src/interrupt/isr/isr.asm
diff --git a/src/interrupt/isr.c b/src/interrupt/isr/isr.c
similarity index 100%
rename from src/interrupt/isr.c
rename to src/interrupt/isr/isr.c

From 2175b1065d3f39f104f6811a557422f41050a3ea Mon Sep 17 00:00:00 2001
From: Ox03bb <ali.de.bouakaz@gmail.com>
Date: Fri, 11 Sep 2026 00:05:09 +0100
Subject: [PATCH 3/6] some updates

---
 includes/interrupt/pit.h | 30 ++++++++++++++++++++++++++++++
 src/interrupt/irq/irq.c  | 15 ++++++++++-----
 src/interrupt/pit.c      | 12 ++++++++++++
 3 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/includes/interrupt/pit.h b/includes/interrupt/pit.h
index ab61170..9abedc7 100644
--- a/includes/interrupt/pit.h
+++ b/includes/interrupt/pit.h
@@ -2,13 +2,43 @@
 #define PIT_H
 
 #define PIT_CHANNEL0  0x40
+#define PIT_CHANNEL1  0x41
+#define PIT_CHANNEL2  0x42
 #define PIT_COMMAND   0x43
 #define PIT_BASE_FREQ 1193182
 
 #include <stdint.h>
 
+/* Channels */
+#define PIT_CHANNEL_0 0
+#define PIT_CHANNEL_1 1
+#define PIT_CHANNEL_2 2
+
+/* Access modes */
+#define PIT_ACCESS_LATCH    0x00
+#define PIT_ACCESS_LOBYTE   0x10
+#define PIT_ACCESS_HIBYTE   0x20
+#define PIT_ACCESS_LOHI     0x30
+
+/* Operating modes */
+#define PIT_MODE_0 0x00
+#define PIT_MODE_1 0x02
+#define PIT_MODE_2 0x04
+#define PIT_MODE_3 0x06
+#define PIT_MODE_4 0x08
+#define PIT_MODE_5 0x0A
+
+/* Binary mode */
+#define PIT_BINARY 0x00
+
+uint16_t div;
+uint32_t freq;
+
+
 void pit_init(uint32_t frequency);
 void pit_set_frequency(uint32_t frequency);
 uint16_t pit_calculate_divisor(uint32_t frequency);
+uint16_t get_divisor();
+uint32_t get_frequency();
 
 #endif
\ No newline at end of file
diff --git a/src/interrupt/irq/irq.c b/src/interrupt/irq/irq.c
index 31ec781..e431b3f 100644
--- a/src/interrupt/irq/irq.c
+++ b/src/interrupt/irq/irq.c
@@ -5,10 +5,15 @@
 
 void irq_handler(uint32_t vector) {
 
-    vga_print("IRQ: ");
-    vga_print_hex(vector);
-    vga_print("\n");
-
+    if (vector == 0){
+        vga_print("Time IRQ \n");
+    }else{
+        vga_print("IRQ: ");
+        vga_print_hex(vector);
+        vga_print("\n");
+    }
+    
     pic_send_eoi((uint8_t)vector);
 
-}
\ No newline at end of file
+}
+
diff --git a/src/interrupt/pit.c b/src/interrupt/pit.c
index 10738f7..8aa8a16 100644
--- a/src/interrupt/pit.c
+++ b/src/interrupt/pit.c
@@ -9,6 +9,9 @@ void pit_init(uint32_t frequency){
 
 void pit_set_frequency(uint32_t frequency){
     uint16_t divisor = pit_calculate_divisor(frequency);
+    
+    div = divisor;
+    freq = frequency;
 
     outb(PIT_COMMAND, 0x34); // ch 0, mode 2, binary
 
@@ -32,4 +35,13 @@ uint16_t pit_calculate_divisor(uint32_t frequency)
         divisor = 65535;
 
     return (uint16_t)divisor;
+}
+
+
+uint16_t get_divisor(){
+    return div;
+}
+
+uint32_t get_frequency(){
+    return freq;
 }
\ No newline at end of file

From d77606f18b6ab36fd4f52ef5fc7fe60ad4563414 Mon Sep 17 00:00:00 2001
From: Ox03bb <ali.de.bouakaz@gmail.com>
Date: Fri, 11 Sep 2026 00:42:33 +0100
Subject: [PATCH 4/6] fix sone error

---
 includes/interrupt/idt.h | 1 -
 includes/interrupt/pit.h | 4 ++--
 src/interrupt/pit.c      | 3 +++
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/includes/interrupt/idt.h b/includes/interrupt/idt.h
index c5ec1cd..95909f4 100644
--- a/includes/interrupt/idt.h
+++ b/includes/interrupt/idt.h
@@ -29,7 +29,6 @@ struct idtr {
 void idt_set_gate(uint8_t vector, uint32_t handler, uint16_t selector, uint8_t type_attr);
 
 void idt_init_descriptor(void);
-static void idt_load(void);
 void idt_init(void);
 
 void idt_clear(void);
diff --git a/includes/interrupt/pit.h b/includes/interrupt/pit.h
index 9abedc7..7770a20 100644
--- a/includes/interrupt/pit.h
+++ b/includes/interrupt/pit.h
@@ -31,8 +31,8 @@
 /* Binary mode */
 #define PIT_BINARY 0x00
 
-uint16_t div;
-uint32_t freq;
+extern uint16_t div;
+extern uint32_t freq;
 
 
 void pit_init(uint32_t frequency);
diff --git a/src/interrupt/pit.c b/src/interrupt/pit.c
index 8aa8a16..f630a60 100644
--- a/src/interrupt/pit.c
+++ b/src/interrupt/pit.c
@@ -2,6 +2,9 @@
 #include "utils.h"
 #include <stdint.h>
 
+uint16_t div;
+uint32_t freq;
+
 void pit_init(uint32_t frequency){
     pit_set_frequency(frequency);
 }

From 3dcace98eb80ffe730c3e4c1bf7e3e9f6fa07183 Mon Sep 17 00:00:00 2001
From: Ox03bb <ali.de.bouakaz@gmail.com>
Date: Fri, 11 Sep 2026 01:45:52 +0100
Subject: [PATCH 5/6] complite the timer

---
 includes/interrupt/pit.h | 12 ++++--------
 includes/timer.h         | 20 ++++++++++++++++++++
 src/driver/vga.c         |  2 +-
 src/interrupt/irq/irq.c  | 21 ++++++++++++---------
 src/interrupt/pit.c      | 23 ++++++-----------------
 src/kernel/kernel.c      | 25 ++++++++++++++++---------
 src/kernel/timer.c       | 31 +++++++++++++++++++++++++++++++
 7 files changed, 90 insertions(+), 44 deletions(-)
 create mode 100644 includes/timer.h
 create mode 100644 src/kernel/timer.c

diff --git a/includes/interrupt/pit.h b/includes/interrupt/pit.h
index 7770a20..80c244e 100644
--- a/includes/interrupt/pit.h
+++ b/includes/interrupt/pit.h
@@ -15,10 +15,10 @@
 #define PIT_CHANNEL_2 2
 
 /* Access modes */
-#define PIT_ACCESS_LATCH    0x00
-#define PIT_ACCESS_LOBYTE   0x10
-#define PIT_ACCESS_HIBYTE   0x20
-#define PIT_ACCESS_LOHI     0x30
+#define PIT_ACCESS_LATCH  0x00
+#define PIT_ACCESS_LOBYTE 0x10
+#define PIT_ACCESS_HIBYTE 0x20
+#define PIT_ACCESS_LOHI   0x30
 
 /* Operating modes */
 #define PIT_MODE_0 0x00
@@ -31,10 +31,6 @@
 /* Binary mode */
 #define PIT_BINARY 0x00
 
-extern uint16_t div;
-extern uint32_t freq;
-
-
 void pit_init(uint32_t frequency);
 void pit_set_frequency(uint32_t frequency);
 uint16_t pit_calculate_divisor(uint32_t frequency);
diff --git a/includes/timer.h b/includes/timer.h
new file mode 100644
index 0000000..c1979dc
--- /dev/null
+++ b/includes/timer.h
@@ -0,0 +1,20 @@
+#ifndef TIMER_H
+#define TIMER_H
+
+#include <stdint.h>
+
+void timer_init(uint32_t frequency);
+
+void timer_irq_handler(void);
+
+uint32_t timer_get_ticks(void);
+
+uint32_t timer_get_seconds(void);
+
+uint32_t timer_get_frequency(void);
+
+void timer_sleep_m(uint32_t milliseconds);
+void timer_sleep_s(uint32_t seconds);
+void timer_sleep(float seconds);
+
+#endif
\ No newline at end of file
diff --git a/src/driver/vga.c b/src/driver/vga.c
index d475c34..d489ce7 100644
--- a/src/driver/vga.c
+++ b/src/driver/vga.c
@@ -35,7 +35,7 @@ void vga_print(const char *str) {
         return;
     }
 
-    for (uint64_t i = 0; str[i] != '\0'; i++) {
+    for (uint32_t i = 0; str[i] != '\0'; i++) {
         if (str[i] == '\n') {
             uint8_t y = vga_get_cursor_y() + 1;
             vga_set_cursor(0, y);
diff --git a/src/interrupt/irq/irq.c b/src/interrupt/irq/irq.c
index e431b3f..33d5b7a 100644
--- a/src/interrupt/irq/irq.c
+++ b/src/interrupt/irq/irq.c
@@ -1,19 +1,22 @@
 #include "irq.h"
+#include "pic.h"
+#include "timer.h"
 #include "vga.h"
 #include "vga_lib.h"
-#include "pic.h"
 
 void irq_handler(uint32_t vector) {
 
-    if (vector == 0){
-        vga_print("Time IRQ \n");
-    }else{
+    switch (vector) {
+    case 0:
+        timer_irq_handler();
+        pic_send_eoi((uint8_t)vector);
+        break;
+
+    default:
         vga_print("IRQ: ");
         vga_print_hex(vector);
         vga_print("\n");
-    }
-    
-    pic_send_eoi((uint8_t)vector);
-
-}
 
+        pic_send_eoi((uint8_t)vector);
+    }
+}
\ No newline at end of file
diff --git a/src/interrupt/pit.c b/src/interrupt/pit.c
index f630a60..1737898 100644
--- a/src/interrupt/pit.c
+++ b/src/interrupt/pit.c
@@ -5,14 +5,11 @@
 uint16_t div;
 uint32_t freq;
 
-void pit_init(uint32_t frequency){
-    pit_set_frequency(frequency);
-}
-
+void pit_init(uint32_t frequency) { pit_set_frequency(frequency); }
 
-void pit_set_frequency(uint32_t frequency){
+void pit_set_frequency(uint32_t frequency) {
     uint16_t divisor = pit_calculate_divisor(frequency);
-    
+
     div = divisor;
     freq = frequency;
 
@@ -20,12 +17,9 @@ void pit_set_frequency(uint32_t frequency){
 
     outb(PIT_CHANNEL0, (uint8_t)(divisor & 0xFF));        // Low byte
     outb(PIT_CHANNEL0, (uint8_t)((divisor >> 8) & 0xFF)); // High byte
-
 }
 
-
-uint16_t pit_calculate_divisor(uint32_t frequency)
-{
+uint16_t pit_calculate_divisor(uint32_t frequency) {
     if (frequency == 0)
         return 0;
 
@@ -40,11 +34,6 @@ uint16_t pit_calculate_divisor(uint32_t frequency)
     return (uint16_t)divisor;
 }
 
+uint16_t get_divisor() { return div; }
 
-uint16_t get_divisor(){
-    return div;
-}
-
-uint32_t get_frequency(){
-    return freq;
-}
\ No newline at end of file
+uint32_t get_frequency() { return freq; }
\ No newline at end of file
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index 72fd6a3..a907122 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -1,12 +1,18 @@
 #include "kernel.h"
+
 #include "idt.h"
-#include "panic.h"
+
 #include "pic.h"
 #include "pit.h"
-#include "utils.h"
+#include "timer.h"
+
 #include "vga.h"
 #include "vga_lib.h"
 
+#include "panic.h"
+
+#include "utils.h"
+
 void kernel_main() {
 
     vga_init();
@@ -21,16 +27,17 @@ void kernel_main() {
     idt_init();
     vga_print_at_end_c("... Ok\n", GREEN);
 
-    vga_log_info("[", "init", "] pit");
+    vga_log_info("[", "init", "] pit and timer");
     pic_clear_mask(0);
-    pit_init(100); // 100 Hz
-    vga_print_at_end_c("... Ok\n", GREEN);
+    timer_init(1000); // 1000 Hz
+    sti();
 
-    // asm volatile("int $0x22");
-
-    // panic("testing panics");
+    for (int i = 0; i < 53; i++) {
+        vga_print(".");
+        timer_sleep(0.02);
+    }
 
-    asm volatile("sti");
+    vga_print_at_end_c("... Ok\n", GREEN);
 
     for (;;) {
         asm volatile("hlt");
diff --git a/src/kernel/timer.c b/src/kernel/timer.c
new file mode 100644
index 0000000..17d661f
--- /dev/null
+++ b/src/kernel/timer.c
@@ -0,0 +1,31 @@
+#include "timer.h"
+#include "pit.h"
+#include "vga.h"
+
+static uint32_t ticks = 0;
+static uint32_t timer_frequency = 0;
+
+void timer_init(uint32_t frequency) {
+    timer_frequency = frequency;
+    pit_init(frequency);
+}
+
+void timer_irq_handler(void) { ticks++; }
+
+uint32_t timer_get_ticks(void) { return ticks; }
+
+uint32_t timer_get_seconds(void) { return ticks / timer_frequency; }
+
+uint32_t timer_get_frequency(void) { return timer_frequency; }
+
+void timer_sleep_m(uint32_t milliseconds) {
+    uint32_t start = timer_get_ticks();
+    uint32_t wait_ticks = ((uint32_t)milliseconds * timer_frequency) / 1000;
+
+    while (timer_get_ticks() - start < wait_ticks) {
+    }
+}
+
+void timer_sleep_s(uint32_t seconds) { timer_sleep_m(seconds * 1000); }
+
+void timer_sleep(float seconds) { timer_sleep_m((uint32_t)(seconds * 1000)); }
\ No newline at end of file

From ab86e07d4a0aa1a70fe8fd6e53f6bb3034b946a5 Mon Sep 17 00:00:00 2001
From: Ox03bb <ali.de.bouakaz@gmail.com>
Date: Fri, 11 Sep 2026 01:46:12 +0100
Subject: [PATCH 6/6] complite timer

---
 src/kernel/kernel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index a907122..775cd3c 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -30,14 +30,14 @@ void kernel_main() {
     vga_log_info("[", "init", "] pit and timer");
     pic_clear_mask(0);
     timer_init(1000); // 1000 Hz
+    
     sti();
 
     for (int i = 0; i < 53; i++) {
         vga_print(".");
         timer_sleep(0.02);
     }
-
-    vga_print_at_end_c("... Ok\n", GREEN);
+    vga_print_at_end_c("... Ok\n", GREEN);  // timer 
 
     for (;;) {
         asm volatile("hlt");