- heap allocator now makes sure virtual memory pages are mapped before using them. this means we no longer have to use page faults to allocate frames, it is done automatically.

- fixed the apic code that caused a page fault. it now writes the correct values at the correct physical address
- improved startup logging including displaying how much RAM is installed.

kernel/src/arch/x86_64/cpu/apic.rs

@@ -1,12 +1,12 @@
 use core::arch::x86_64::__cpuid;
 
 use crate::arch::x86_64::memory::mapping::PHYSICAL_MEMORY_OFFSET;
-use crate::{serial_print, serial_println};
+use crate::{debugln, serial_print, serial_println};
 use x86_64::{
     PhysAddr, VirtAddr,
     structures::paging::{Mapper, Page, PageTableFlags, PhysFrame, Size4KiB},
 };
-
+use x86_64::structures::paging::Translate;
 use crate::arch::x86_64::cpu::msr::*;
 use crate::arch::x86_64::memory::{FRAME_ALLOCATOR, OFFSET_PAGE_TABLE};
 
@@ -26,9 +26,11 @@ const CPUID_FEAT_EDX_APIC: u64 = 1 << 9; // the cpuid instruction will return th
 
 fn set_apic_base_enable(apic: PhysAddr) {
     let rax = (apic.as_u64() & 0xfffff0000) | IA32_APIC_BASE_MSR_ENABLE;
+    debugln!("apic {:?}", PhysAddr::new(rax));
     cpu_set_msr(IA32_APIC_BASE_MSR, rax);
 }
 
+#[allow(dead_code)]
 fn set_apic_base_disable(apic: PhysAddr) {
     let rax = (apic.as_u64() & 0xfffff0000) & IA32_APIC_BASE_MSR_DISABLE;
     cpu_set_msr(IA32_APIC_BASE_MSR, rax);
@@ -37,22 +39,27 @@ fn set_apic_base_disable(apic: PhysAddr) {
 fn get_apic_base() -> PhysAddr {
     let mut value: u64 = 0;
     cpu_get_msr(IA32_APIC_BASE_MSR, &mut value);
+
+    debugln!("apic base {:#x}", value);
+
     PhysAddr::new(value & 0xfffff0000)
 }
 
-fn write_apic_register(apic_base: &PhysAddr, reg: u8, value: u32) {
+fn write_apic_register(apic_base: &PhysAddr, reg: u64, value: u32) {
     let apic_base = apic_base.as_u64();
-    let reg_addr = (apic_base & 0xFFFFF0000) + reg as u64;
+    let reg_addr = (apic_base & 0xFFFFF0000) + reg;
+
     let virt_addr = unsafe { phys_to_virt(PhysAddr::new(reg_addr)) };
+
+    let phys_check = OFFSET_PAGE_TABLE.get().unwrap().lock().translate(virt_addr);
+    debugln!("{:?}", phys_check);
+
     unsafe { *(virt_addr.as_u64() as *mut u32) = value };
 }
 
-fn read_apic_register(apic_base: &PhysAddr, reg: u8) -> u32 {
+fn read_apic_register(apic_base: &PhysAddr, reg: u64) -> u32 {
     let apic_base = apic_base.as_u64();
-    let reg_addr = (apic_base & 0xFFFFF0000) + reg as u64;
-
-    serial_println!("reading: {:?}", VirtAddr::new(reg_addr));
-
+    let reg_addr = (apic_base & 0xFFFFF0000) + reg;
     let virt_addr = unsafe { phys_to_virt(PhysAddr::new(reg_addr)) };
     unsafe { *(virt_addr.as_u64() as *const u32) }
 }
@@ -70,23 +77,22 @@ unsafe fn phys_to_virt(phys: PhysAddr) -> VirtAddr {
 }
 
 pub fn enable_apic() {
-    let mut mapper = OFFSET_PAGE_TABLE.get().unwrap().lock();
-    let mut frame_allocator = FRAME_ALLOCATOR.get().unwrap().lock();
+    let apic_base_physical_addr = get_apic_base();
+    set_apic_base_enable(apic_base_physical_addr);
 
-    let apic_phys_addr = get_apic_base();
-    set_apic_base_enable(apic_phys_addr);
-    // map virt address of apic
-    let apic_virt = unsafe { phys_to_virt(apic_phys_addr) };
+    debugln!("{:?}", apic_base_physical_addr);
+    enable_timer();
 
-    serial_println!("Trying to map: {:?} -> {:?}", apic_virt, apic_phys_addr);
+    write_apic_register(
+        &apic_base_physical_addr,
+        0xF0,
+        read_apic_register(&apic_base_physical_addr, 0xF0) | 0x1FF
+    );
 
-    // FIXME: this causes a page fault
-    // TODO: map to virtual memory
-
-    let reg = read_apic_register(&apic_phys_addr, 0xF0);
-    write_apic_register(&apic_phys_addr, 0xF0, reg | 0x100);
 }
 
-pub struct Apic {}
-
-pub enum ApicVector {}
+pub fn enable_timer() {
+    let apic_base = get_apic_base();
+    let current = read_apic_register(&apic_base, 0x320);
+    write_apic_register(&get_apic_base(), 0x320, (current & 0xFFFFFF00) | 0x20);
+}