From b9ab8da576af85cc67a69fdf0218fa8784e9d2b1 Mon Sep 17 00:00:00 2001
From: Mathieu Strypsteen <mathieu@strypsteen.me>
Date: Fri, 22 Nov 2024 11:21:27 +0100
Subject: [PATCH] Fix booting on real hardware

---
 kernel/src/sys/acpica_osl.rs |  5 +++--
 kernel/src/sys/hpet.rs       |  2 +-
 kernel/src/sys/ioapic.rs     | 15 ++++++++-------
 kernel/src/sys/madt.rs       |  2 +-
 4 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/kernel/src/sys/acpica_osl.rs b/kernel/src/sys/acpica_osl.rs
index 2690a38..70dfb03 100644
--- a/kernel/src/sys/acpica_osl.rs
+++ b/kernel/src/sys/acpica_osl.rs
@@ -24,6 +24,7 @@ static SCI_HANDLER: Mutex<Option<unsafe extern "C" fn(context: *mut c_void) -> U
 static SCI_CONTEXT: AtomicPtr<c_void> = AtomicPtr::new(null_mut());
 
 use super::{
+    hpet::get_current_time,
     sync::{create_semaphore, lock_semaphore, unlock_semaphore, Semaphore, Spinlock},
     task::{CURRENT_TASK, CURRENT_TASK_LOCK, MULTITASKING_ENABLED},
 };
@@ -100,8 +101,8 @@ extern "C" fn AcpiOsGetThreadId() -> UINT64 {
     task_id as UINT64
 }
 #[no_mangle]
-extern "C" fn AcpiOsGetTimer() {
-    unimplemented!();
+extern "C" fn AcpiOsGetTimer() -> UINT64 {
+    get_current_time() as UINT64 * 10
 }
 #[no_mangle]
 extern "C" fn AcpiOsInitialize() -> ACPI_STATUS {
diff --git a/kernel/src/sys/hpet.rs b/kernel/src/sys/hpet.rs
index e3c0979..474273f 100644
--- a/kernel/src/sys/hpet.rs
+++ b/kernel/src/sys/hpet.rs
@@ -89,7 +89,7 @@ fn handler() {
         SLEEP_LOCK.unlock();
     }
 }
-fn get_current_time() -> usize {
+pub fn get_current_time() -> usize {
     let address = ADDRESS.load(Ordering::SeqCst);
     let current_counter = unsafe { address.add(REGISTER_COUNTER).read_volatile() };
     ticks_to_us(current_counter as usize)
diff --git a/kernel/src/sys/ioapic.rs b/kernel/src/sys/ioapic.rs
index 10133ec..4fa680f 100644
--- a/kernel/src/sys/ioapic.rs
+++ b/kernel/src/sys/ioapic.rs
@@ -1,6 +1,6 @@
 use core::{
     ptr::null_mut,
-    sync::atomic::{AtomicPtr, AtomicU32, Ordering},
+    sync::atomic::{AtomicPtr, AtomicU32, AtomicUsize, Ordering},
 };
 
 use bitfield::bitfield;
@@ -36,6 +36,7 @@ const REGISTER_VERSION: u8 = 1;
 const REGISTER_REDIRECTION: u8 = 0x10;
 
 static IOAPICS: [IOAPIC; 32] = [EMPTY_IOAPIC; 32];
+static NEXT_IOAPIC_ID: AtomicUsize = AtomicUsize::new(0);
 
 fn read_register(apic_i: usize, reg_i: u8) -> u32 {
     unsafe {
@@ -92,13 +93,13 @@ pub fn register_irq_handler(vector: usize, handler: fn()) {
         }
     }
 }
-pub fn setup_ioapic(apic_i: u8, phys: u64, gsi_base: u32) {
-    let apic_i = apic_i as usize;
+pub fn setup_ioapic(phys: u64, gsi_base: u32) {
     let address = unsafe { map_physical(phys, 0x14, false) as *mut u32 };
-    IOAPICS[apic_i].address.store(address, Ordering::SeqCst);
-    IOAPICS[apic_i].start_gsi.store(gsi_base, Ordering::SeqCst);
-    let max_ints = (read_register(apic_i, REGISTER_VERSION) >> 16) & 0xff;
-    IOAPICS[apic_i].end_gsi.store(gsi_base + max_ints, Ordering::SeqCst);
+    let next_id = NEXT_IOAPIC_ID.fetch_add(1, Ordering::SeqCst);
+    IOAPICS[next_id].address.store(address, Ordering::SeqCst);
+    IOAPICS[next_id].start_gsi.store(gsi_base, Ordering::SeqCst);
+    let max_ints = (read_register(next_id, REGISTER_VERSION) >> 16) & 0xff;
+    IOAPICS[next_id].end_gsi.store(gsi_base + max_ints, Ordering::SeqCst);
     assert!(gsi_base + max_ints < 128);
     for i in gsi_base..gsi_base + max_ints {
         let mut redirection = RedirectionEntry(0);
diff --git a/kernel/src/sys/madt.rs b/kernel/src/sys/madt.rs
index 55b44d2..68814ff 100644
--- a/kernel/src/sys/madt.rs
+++ b/kernel/src/sys/madt.rs
@@ -21,7 +21,7 @@ pub fn parse_madt(tables: &AcpiTables<EarlyACPIHandler>) {
     setup_lapic(lapic_address);
     for i in madt.entries() {
         if let MadtEntry::IoApic(ioapic) = i {
-            setup_ioapic(ioapic.io_apic_id, ioapic.io_apic_address as u64, ioapic.global_system_interrupt_base);
+            setup_ioapic(ioapic.io_apic_address as u64, ioapic.global_system_interrupt_base);
         }
     }
     for i in madt.entries() {