From c444c992313a8cf29a8f4d97d668d71c2df9e0a9 Mon Sep 17 00:00:00 2001
From: Sarah <sarah.simon@rwth-aachen.de>
Date: Wed, 13 Dec 2023 15:27:14 +0100
Subject: [PATCH] revert SMP boot for BIOS systems to previous way, WIP for
 UEFI systems (currently only one core supported)

---
 src/arch/x86_64/kernel/apic.rs | 43 ++++++++++++++++++++++++----------
 1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/arch/x86_64/kernel/apic.rs b/src/arch/x86_64/kernel/apic.rs
index 367b51d21b..590642916a 100644
--- a/src/arch/x86_64/kernel/apic.rs
+++ b/src/arch/x86_64/kernel/apic.rs
@@ -693,20 +693,37 @@ pub fn boot_application_processors() {
 		"SMP Boot Code is larger than a page"
 	);
 	debug!("SMP boot code is {} bytes long", smp_boot_code.len());
+	// We can only allocate full pages of physmem
+
+	if crate::kernel::is_uefi() {
+		// Currently, this does NOT work as intended, this only supports one core
+		let length = BasePageSize::SIZE as usize;
+		let phys_addr: PhysAddr = crate::arch::mm::physicalmem::allocate(length).unwrap();
+
+		let mut flags = PageTableEntryFlags::empty();
+		flags.normal().writable();
+		debug!(
+			"Mapping SMP boot code from physical address {phys_addr:x} to virtual address {:p}",
+			SMP_BOOT_CODE_ADDRESS
+		);
+		//map physical memory to SMP_BOOT_CODE_ADDRESS in virtual memory
+		paging::map::<BasePageSize>(SMP_BOOT_CODE_ADDRESS, phys_addr, 1, flags);
+	} else {
+		// Identity-map the boot code page and copy over the code.
+		debug!(
+			"Mapping SMP boot code to physical and virtual address {:p}",
+			SMP_BOOT_CODE_ADDRESS
+		);
+		let mut flags = PageTableEntryFlags::empty();
+		flags.normal().writable();
+		paging::map::<BasePageSize>(
+			SMP_BOOT_CODE_ADDRESS,
+			PhysAddr(SMP_BOOT_CODE_ADDRESS.as_u64()),
+			1,
+			flags,
+		);
+	}
 
-	// Identity-map the boot code page and copy over the code.
-	debug!(
-		"Mapping SMP boot code to physical and virtual address {:p}",
-		SMP_BOOT_CODE_ADDRESS
-	);
-	let mut flags = PageTableEntryFlags::empty();
-	flags.normal().writable();
-	paging::map::<BasePageSize>(
-		SMP_BOOT_CODE_ADDRESS,
-		PhysAddr(SMP_BOOT_CODE_ADDRESS.as_u64()),
-		1,
-		flags,
-	);
 	unsafe {
 		ptr::copy_nonoverlapping(
 			smp_boot_code.as_ptr(),