RSDP validation and fixing a few clippy lints

src/acpi/rsdp.rs

@@ -9,7 +9,7 @@ pub struct Rsdp {
     _oemid: [u8; 6],
     revision: u8,
     rsdt_address: u32,
-    _length: u32,
+    length: u32,
     xsdt_address: u64,
     _extended_checksum: u8,
     _reserved: [u8; 3],
@@ -18,8 +18,26 @@ pub struct Rsdp {
 impl Rsdp {
     pub unsafe fn get_rsdp(already_supplied_rsdp: Option<*const u8>) -> Option<Rsdp> {
         already_supplied_rsdp.map(|rsdp_ptr| {
-            // TODO: Validate
+            let rsdp = unsafe { *(rsdp_ptr as *const Rsdp) };
-            unsafe { *(rsdp_ptr as *const Rsdp) }
+
+            assert_eq!(rsdp.signature, *b"RSD PTR ", "RSDP signature check failed");
+
+            let mut sum: u8 = 0;
+            for i in 0..20 {
+                sum = sum.wrapping_add(unsafe { rsdp_ptr.add(i).read() });
+            }
+            assert_eq!(sum, 0, "RSDP checksum failed");
+
+
+            if rsdp.revision >= 2 {
+                let mut sum: u8 = 0;
+                for i in 0..rsdp.length as usize {
+                    sum = sum.wrapping_add(unsafe { rsdp_ptr.add(i).read() });
+                }
+                assert_eq!(sum, 0, "XSDP checksum failed");
+            }
+
+            rsdp
         })
     }
 

src/context/switch.rs

@@ -513,7 +513,7 @@ fn select_next_context(
 
     if let Some((next_context_guard, addr_space)) = next_context_guard_opt {
         // We found a new process!
-        return Some((next_context_guard, addr_space));
+        Some((next_context_guard, addr_space))
     } else {
         if !was_idle && !Arc::ptr_eq(&prev_context_lock, &idle_context) {
             // We switch into the idle context

src/memory/mod.rs

@@ -555,7 +555,7 @@ fn init_sections(mut allocator: BumpAllocator<RmmA>) {
 
         assert_ne!(
             memory_map_area.size, 0,
-            "RMM should enforce areas are not zeroed"
+            "RMM should enforce areas are not of length 0"
         );
 
         // TODO: Should RMM do this?

src/profiling.rs

@@ -188,6 +188,7 @@ pub unsafe fn nmi_handler(stack: &InterruptStack) {
 
     let mut len = 2;
 
+    #[expect(clippy::needless_range_loop)]
     for i in 2..32 {
         if bp < CurrentRmmArch::PHYS_OFFSET
             || bp.saturating_add(16) >= CurrentRmmArch::PHYS_OFFSET + crate::PML4_SIZE
@@ -303,7 +304,7 @@ pub fn maybe_run_profiling_helper_forever(cpu_id: LogicalCpuId) {
         let apic = &mut crate::arch::device::local_apic::the_local_apic();
         apic.set_lvt_timer((0b01 << 17) | 32);
         apic.set_div_conf(0b1011);
-        apic.set_init_count(0xffff_f);
+        apic.set_init_count(0x000f_ffff);
 
         while ACK.load(Ordering::Relaxed) < NUM_ORDINARY_CPUS.load(Ordering::SeqCst) {
             core::hint::spin_loop();

src/scheme/debug.rs

@@ -37,6 +37,7 @@ pub fn debug_notify(token: &mut CleanLockToken) {
 
 pub struct DebugScheme;
 
+#[expect(clippy::enum_clike_unportable_variant)]
 #[repr(usize)]
 enum SpecialFds {
     Default = -1isize as usize,

src/scheme/sys/context.rs

@@ -19,7 +19,7 @@ pub fn resource(token: &mut CleanLockToken) -> Result<Vec<u8>> {
         let (contexts, mut token) = contexts.token_split();
         for context_ref in contexts.iter() {
             let context = context_ref.read(token.token());
-            let addr_space = context.addr_space().map(|a| a.clone());
+            let addr_space = context.addr_space().cloned();
 
             let affinity = context.sched_affinity.to_string();
             let cpu_time_s = context.cpu_time / crate::time::NANOS_PER_SEC;