From 28c95303e9c33029d93422f05318dda6b65d4cfd Mon Sep 17 00:00:00 2001
From: kamkow1 <kamkow256@gmail.com>
Date: Tue, 18 Nov 2025 23:27:49 +0100
Subject: [PATCH] Fix PIC, add small delays when initializing

---
 kernel/intr/intr.c     | 17 +++++++++++------
 kernel/intr/pic.c      | 30 ++++++++++++++++++++++++++----
 kernel/intr/pic.h      |  6 +++++-
 kernel/intr/pit.c      |  6 ------
 kernel/io/io.c         |  4 ++++
 kernel/io/io.h         |  2 ++
 kernel/proc/proc.c     |  8 ++------
 run/qemu-x86_64-hdd.sh |  2 +-
 8 files changed, 51 insertions(+), 24 deletions(-)

diff --git a/kernel/intr/intr.c b/kernel/intr/intr.c
index 57d602a..fed3523 100644
--- a/kernel/intr/intr.c
+++ b/kernel/intr/intr.c
@@ -186,7 +186,6 @@ void intr_init(void) {
   idt_init();
   intr_pic_init();
   intr_pit_init();
-  intr_disable();
 }
 
 void intr_dumpframe(IntrStackFrame *frame) {
@@ -246,12 +245,18 @@ void intr_handleintr(IntrStackFrame *frame) {
       cpu_hang();
     }
   } else if (frame->trapnum >= 32 && frame->trapnum <= 47) {
-    intr_pic_eoi();
-    IntrHandler *ih, *ihtmp;
-    LL_FOREACH_SAFE(INTR_HANDLERS, ih, ihtmp) {
-      if ((uint64_t)ih->irq == frame->trapnum) {
-        ih->fn(frame);
+    if (frame->trapnum == INTR_IRQBASE+0) {
+      PIT_TICKS++;
+      intr_pic_eoi(frame->trapnum >= 40);
+      proc_sched((void *)frame);
+    } else {
+      IntrHandler *ih, *ihtmp;
+      LL_FOREACH_SAFE(INTR_HANDLERS, ih, ihtmp) {
+        if ((uint64_t)ih->irq == frame->trapnum) {
+          ih->fn(frame);
+        }
       }
+      intr_pic_eoi(frame->trapnum >= 40);
     }
   } else if (frame->trapnum == 0x80) {
     intr_syscalldispatch(frame);
diff --git a/kernel/intr/pic.c b/kernel/intr/pic.c
index 7465df4..3d945d2 100644
--- a/kernel/intr/pic.c
+++ b/kernel/intr/pic.c
@@ -25,22 +25,44 @@
 
 void intr_pic_init(void) {
   io_out8(PIC1_CMD, ICW1_INIT | ICW1_ICW4);
+  io_wait();
   io_out8(PIC2_CMD, ICW1_INIT | ICW1_ICW4);
+  io_wait();
 
   io_out8(PIC1_DATA, INTR_IRQBASE);
+  io_wait();
   io_out8(PIC2_DATA, INTR_IRQBASE+8);
+  io_wait();
 
   io_out8(PIC1_DATA, 2);
+  io_wait();
   io_out8(PIC2_DATA, 2);
+  io_wait();
 
   io_out8(PIC1_DATA, ICW4_8086);
+  io_wait();
   io_out8(PIC2_DATA, ICW4_8086);
+  io_wait();
 
-  io_out8(PIC1_DATA, 0);
-  io_out8(PIC2_DATA, 0);
+  intr_pic_mask();
 }
 
-void intr_pic_eoi(void) {
-  io_out8(PIC2_CMD, PIC_EOI);
+void intr_pic_mask(void) {
+  io_out8(PIC1_DATA, 0xFF);
+  io_wait();
+  io_out8(PIC2_DATA, 0xFF);
+  io_wait();
+}
+
+void intr_pic_unmask(void) {
+  io_out8(PIC1_DATA, 0);
+  io_wait();
+  io_out8(PIC2_DATA, 0);
+  io_wait();
+}
+
+void intr_pic_eoi(bool pic2) {
+  if (pic2)
+    io_out8(PIC2_CMD, PIC_EOI);
   io_out8(PIC1_CMD, PIC_EOI);
 }
diff --git a/kernel/intr/pic.h b/kernel/intr/pic.h
index 7de9b6c..3a4c1e6 100644
--- a/kernel/intr/pic.h
+++ b/kernel/intr/pic.h
@@ -1,7 +1,11 @@
 #ifndef INTR_PIC_H_
 #define INTR_PIC_H_
 
+#include <stdbool.h>
+
 void intr_pic_init(void);
-void intr_pic_eoi(void);
+void intr_pic_eoi(bool pic2);
+void intr_pic_mask(void);
+void intr_pic_unmask(void);
 
 #endif // INTR_PIC_H_
diff --git a/kernel/intr/pit.c b/kernel/intr/pit.c
index de6f508..35125f5 100644
--- a/kernel/intr/pit.c
+++ b/kernel/intr/pit.c
@@ -31,13 +31,7 @@ void intr_pit_wait(uint32_t ms) {
   while (PIT_TICKS - now < ms);
 }
 
-void intr_pit_intr(IntrStackFrame *frame) {
-  PIT_TICKS++;
-}
-
 void intr_pit_init(void) {
-  intr_attchhandler(&intr_pit_intr, INTR_IRQBASE+0);
-
   uint32_t hz = 1000;
   uint32_t div = PIT_FREQ / hz;
   io_out8(PIT_CMD, PIT_CMD_BINARY | PIT_CMD_MODE3 | PIT_CMD_RW_BOTH | PIT_CMD_COUNTER0);
diff --git a/kernel/io/io.c b/kernel/io/io.c
index 57b0f38..d2aa908 100644
--- a/kernel/io/io.c
+++ b/kernel/io/io.c
@@ -45,3 +45,7 @@ void io_outs16(uint16_t port, const void *addr, int cnt) {
     : "memory", "cc"
   );
 }
+
+void io_wait(void) {
+  io_out8(0x80, 0);
+}
diff --git a/kernel/io/io.h b/kernel/io/io.h
index e155240..6ad98cb 100644
--- a/kernel/io/io.h
+++ b/kernel/io/io.h
@@ -15,4 +15,6 @@ void io_out32(uint16_t port, uint32_t value);
 void io_ins16(uint16_t port, void *addr, int cnt);
 void io_outs16(uint16_t port, const void *addr, int cnt);
 
+void io_wait(void);
+
 #endif // IO_IO_H_
diff --git a/kernel/proc/proc.c b/kernel/proc/proc.c
index 03f86a2..69d8b6b 100644
--- a/kernel/proc/proc.c
+++ b/kernel/proc/proc.c
@@ -253,21 +253,17 @@ void proc_killself(void) {
   proc_kill(proc);
 }
 
-void proc_intr(IntrStackFrame *frame) {
-  proc_sched(frame);
-}
-
 void proc_init(void) {
   spinlock_init(&PROCS.spinlock);
   PROCS.procs = NULL;
 
-  intr_attchhandler(&proc_intr, INTR_IRQBASE+0);
-
   Proc *init = proc_spawnuser("base", "/bin/init");
   PROCS.current = init;
   proc_register(init);
   init->state = PROC_READY;
 
+  intr_pic_unmask();
+
   tss.rsp0 = (uint64_t)VIRT(PROCS.current->platformdata.kstack);
   proc_switch(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);
 }
diff --git a/run/qemu-x86_64-hdd.sh b/run/qemu-x86_64-hdd.sh
index 8e10c5b..ea87073 100755
--- a/run/qemu-x86_64-hdd.sh
+++ b/run/qemu-x86_64-hdd.sh
@@ -3,7 +3,7 @@
 set -x
 
 qemu-system-x86_64 \
-  -cpu IvyBridge \
+  -machine pc \
   -m 4G \
   -boot d \
   -serial stdio \