Allocate a very small 4K stack for the other CPUs, increase count to 4

Makefile

@@ -10,7 +10,7 @@ bochs: build/harddrive.bin
 	bochs -f bochs.$(ARCH)
 
 qemu: build/harddrive.bin
-	qemu-system-$(ARCH) -enable-kvm -cpu host -smp 2 -machine q35 \
+	qemu-system-$(ARCH) -enable-kvm -cpu host -smp 4 -machine q35 \
 				-serial mon:stdio -drive file=$<,format=raw,index=0,media=disk \
 				-nographic -d guest_errors,int,pcall
 				#-device intel-iommu

arch/x86_64/src/acpi/mod.rs

@@ -3,7 +3,7 @@
 
 use core::intrinsics::{atomic_load, atomic_store};
 
-use memory::Frame;
+use memory::{allocate_frame, Frame};
 use paging::{entry, ActivePageTable, Page, PhysicalAddress, VirtualAddress};
 use start::kstart_ap;
 
@@ -50,19 +50,9 @@ pub fn init_sdt(sdt: &'static Sdt, active_table: &mut ActivePageTable) {
                             }
                         }
 
-                        // Map a stack
-                        /*
-                        let stack_start = HEAP_START + HEAP_SIZE + 4096 + (asp_local_apic.id as usize * (1024 * 1024 + 4096));
-                        let stack_end = stack_start + 1024 * 1024;
-                        {
-                            let start_page = Page::containing_address(VirtualAddress::new(stack_start));
-                            let end_page = Page::containing_address(VirtualAddress::new(stack_end - 1));
-
-                            for page in Page::range_inclusive(start_page, end_page) {
-                                active_table.map(page, entry::WRITABLE | entry::NO_EXECUTE);
-                            }
-                        }
-                        */
+                        // Allocate a stack
+                        let stack_start = allocate_frame().expect("no more frames").start_address().get();
+                        let stack_end = stack_start + 4096;
 
                         let ap_ready = TRAMPOLINE as *mut u64;
                         let ap_stack_start = unsafe { ap_ready.offset(1) };
@@ -71,8 +61,8 @@ pub fn init_sdt(sdt: &'static Sdt, active_table: &mut ActivePageTable) {
 
                         // Set the ap_ready to 0, volatile
                         unsafe { atomic_store(ap_ready, 0) };
-                        unsafe { atomic_store(ap_stack_start, 0x1000) };
-                        unsafe { atomic_store(ap_stack_end, 0x7000) };
+                        unsafe { atomic_store(ap_stack_start, stack_start as u64) };
+                        unsafe { atomic_store(ap_stack_end, stack_end as u64) };
                         unsafe { atomic_store(ap_code, kstart_ap as u64) };
 
                         // Send INIT IPI

arch/x86_64/src/lib.rs

@@ -83,7 +83,7 @@ macro_rules! interrupt_error {
                 $func
             }
 
-            // Push scratch registers, grab stack pointer
+            // Push scratch registers
             asm!("push rax
                 push rcx
                 push rdx

arch/x86_64/src/start.rs

@@ -3,6 +3,8 @@
 /// It must create the IDT with the correct entries, those entries are
 /// defined in other files inside of the `arch` module
 
+use core::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
+
 use acpi;
 use allocator::{HEAP_START, HEAP_SIZE};
 use externs::memset;
@@ -16,6 +18,8 @@ static BSS_TEST_ZERO: usize = 0;
 /// Test of non-zero values in BSS.
 static BSS_TEST_NONZERO: usize = 0xFFFFFFFFFFFFFFFF;
 
+static BSP_READY: AtomicBool = ATOMIC_BOOL_INIT;
+
 extern {
     /// Kernel main function
     fn kmain() -> !;
@@ -46,6 +50,8 @@ pub unsafe extern fn kstart() -> ! {
             debug_assert_eq!(BSS_TEST_NONZERO, 0xFFFFFFFFFFFFFFFF);
         }
 
+        BSP_READY.store(false, Ordering::SeqCst);
+
         // Set up GDT
         gdt::init();
 
@@ -72,6 +78,13 @@ pub unsafe extern fn kstart() -> ! {
         for page in Page::range_inclusive(heap_start_page, heap_end_page) {
             active_table.map(page, entry::WRITABLE | entry::NO_EXECUTE);
         }
+
+        BSP_READY.store(true, Ordering::SeqCst);
+    }
+
+
+    for _i in 0..10 {
+        print!("BSP\n");
     }
 
     kmain();
@@ -98,6 +111,14 @@ pub unsafe extern fn kstart_ap(stack_start: usize, stack_end: usize) -> ! {
         }
     }
 
+    while ! BSP_READY.load(Ordering::SeqCst) {
+        asm!("pause" : : : : "intel", "volatile");
+    }
+
+    for _i in 0..10 {
+        print!("AP\n");
+    }
+
     loop {
         asm!("hlt");
     }