Cleanup ACPI code, find lower tables

Makefile

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

arch/x86_64/src/acpi/mod.rs

@@ -1,14 +1,16 @@
 //! # ACPI
 //! Code to parse the ACPI tables
 
-use core::mem;
-
 use memory::{Frame, FrameAllocator};
 use paging::{entry, ActivePageTable, Page, PhysicalAddress, VirtualAddress};
 
-use self::sdt::SDTHeader;
+use self::rsdt::RSDT;
+use self::sdt::SDT;
+use self::xsdt::XSDT;
 
+pub mod rsdt;
 pub mod sdt;
+pub mod xsdt;
 
 /// Parse the ACPI tables to gather CPU, interrupt, and timer information
 pub unsafe fn init<A>(allocator: &mut A, active_table: &mut ActivePageTable) -> Option<Acpi>
@@ -22,7 +24,9 @@ pub unsafe fn init<A>(allocator: &mut A, active_table: &mut ActivePageTable) ->
         let start_frame = Frame::containing_address(PhysicalAddress::new(start_addr));
         let end_frame = Frame::containing_address(PhysicalAddress::new(end_addr));
         for frame in Frame::range_inclusive(start_frame, end_frame) {
-            active_table.identity_map(frame, entry::PRESENT | entry::NO_EXECUTE, allocator);
+            if active_table.translate_page(Page::containing_address(VirtualAddress::new(frame.start_address().get()))).is_none() {
+                active_table.identity_map(frame, entry::PRESENT | entry::NO_EXECUTE, allocator);
+            }
         }
     }
 
@@ -30,15 +34,45 @@ pub unsafe fn init<A>(allocator: &mut A, active_table: &mut ActivePageTable) ->
     if let Some(rsdp) = RSDP::search(start_addr, end_addr) {
         println!("{:?}", rsdp);
 
-        let rsdt_frame = Frame::containing_address(PhysicalAddress::new(rsdp.rsdt_address as usize));
-        active_table.identity_map(rsdt_frame, entry::PRESENT | entry::NO_EXECUTE, allocator);
+        let mut get_sdt = |sdt_address: usize| -> &'static SDT {
+            if active_table.translate_page(Page::containing_address(VirtualAddress::new(sdt_address))).is_none() {
+                let sdt_frame = Frame::containing_address(PhysicalAddress::new(sdt_address));
+                active_table.identity_map(sdt_frame, entry::PRESENT | entry::NO_EXECUTE, allocator);
+            }
+            unsafe { &*(sdt_address as *const SDT) }
+        };
 
-        let sdt = unsafe { &*(rsdp.rsdt_address as usize as *const SDTHeader) };
-        
-        for &c in sdt.signature.iter() {
+        let rxsdt = get_sdt(rsdp.sdt_address());
+
+        for &c in rxsdt.signature.iter() {
             print!("{}", c as char);
         }
-        println!(" {:?}", sdt);
+        println!(":");
+        if let Some(rsdt) = RSDT::new(rxsdt) {
+            println!("{:?}", rsdt);
+            for sdt_address in rsdt.iter() {
+                let sdt = get_sdt(sdt_address);
+                for &c in sdt.signature.iter() {
+                    print!("{}", c as char);
+                }
+                println!(":");
+                println!("{:?}", sdt);
+            }
+        } else if let Some(xsdt) = XSDT::new(rxsdt) {
+            println!("{:?}", xsdt);
+            for sdt_address in xsdt.iter() {
+                let sdt = get_sdt(sdt_address);
+                for &c in sdt.signature.iter() {
+                    print!("{}", c as char);
+                }
+                println!(":");
+                println!("{:?}", sdt);
+            }
+        } else {
+            println!("UNKNOWN RSDT OR XSDT SIGNATURE");
+        }
+    } else {
+        println!("NO RSDP FOUND");
     }
 
     None
@@ -56,19 +90,29 @@ pub struct RSDP {
     revision: u8,
     rsdt_address: u32,
     length: u32,
-    xsdt_address: u32,
+    xsdt_address: u64,
     extended_checksum: u8,
     reserved: [u8; 3]
 }
 
 impl RSDP {
+    /// Search for the RSDP
     pub fn search(start_addr: usize, end_addr: usize) -> Option<RSDP> {
-        for i in 0 .. (end_addr + 1 - start_addr)/mem::size_of::<RSDP>() {
-            let mut rsdp = unsafe { &*(start_addr as *const RSDP).offset(i as isize) };
+        for i in 0 .. (end_addr + 1 - start_addr)/16 {
+            let mut rsdp = unsafe { &*((start_addr + i * 16) as *const RSDP) };
             if &rsdp.signature == b"RSD PTR " {
                 return Some(*rsdp);
             }
         }
         None
     }
+
+    /// Get the RSDT or XSDT address
+    pub fn sdt_address(&self) -> usize {
+        if self.revision >= 2 {
+            self.xsdt_address as usize
+        } else {
+            self.rsdt_address as usize
+        }
+    }
 }

arch/x86_64/src/acpi/rsdt.rs

@@ -0,0 +1,41 @@
+use core::mem;
+
+use super::sdt::SDT;
+
+#[derive(Debug)]
+pub struct RSDT(&'static SDT);
+
+impl RSDT {
+    pub fn new(sdt: &'static SDT) -> Option<RSDT> {
+        if &sdt.signature == b"RSDT" {
+            Some(RSDT(sdt))
+        } else {
+            None
+        }
+    }
+
+    pub fn iter(&self) -> RSDTIter {
+        RSDTIter {
+            sdt: self.0,
+            i: 0
+        }
+    }
+}
+
+pub struct RSDTIter {
+    sdt: &'static SDT,
+    i: usize
+}
+
+impl Iterator for RSDTIter {
+    type Item = usize;
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.i < self.sdt.data_len()/mem::size_of::<u32>() {
+            let item = unsafe { *(self.sdt.data_address() as *const u32).offset(self.i as isize) };
+            self.i += 1;
+            Some(item as usize)
+        } else {
+            None
+        }
+    }
+}

arch/x86_64/src/acpi/sdt.rs

@@ -1,6 +1,8 @@
+use core::mem;
+
 #[derive(Copy, Clone, Debug)]
 #[repr(packed)]
-pub struct SDTHeader {
+pub struct SDT {
   pub signature: [u8; 4],
   pub length: u32,
   pub revision: u8,
@@ -9,5 +11,23 @@ pub struct SDTHeader {
   pub oem_table_id: [u8; 8],
   pub oem_revision: u32,
   pub creator_id: u32,
-  pub creator_revision: u32,
+  pub creator_revision: u32
+}
+
+impl SDT {
+    /// Get the address of this tables data
+    pub fn data_address(&'static self) -> usize {
+        self as *const _ as usize + mem::size_of::<SDT>()
+    }
+
+    /// Get the length of this tables data
+    pub fn data_len(&'static self) -> usize {
+        let total_size = self.length as usize;
+        let header_size = mem::size_of::<SDT>();
+        if total_size >= header_size {
+            total_size - header_size
+        } else {
+            0
+        }
+    }
 }

arch/x86_64/src/acpi/xsdt.rs

@@ -0,0 +1,41 @@
+use core::mem;
+
+use super::sdt::SDT;
+
+#[derive(Debug)]
+pub struct XSDT(&'static SDT);
+
+impl XSDT {
+    pub fn new(sdt: &'static SDT) -> Option<XSDT> {
+        if &sdt.signature == b"XSDT" {
+            Some(XSDT(sdt))
+        } else {
+            None
+        }
+    }
+
+    pub fn iter(&self) -> XSDTIter {
+        XSDTIter {
+            sdt: self.0,
+            i: 0
+        }
+    }
+}
+
+pub struct XSDTIter {
+    sdt: &'static SDT,
+    i: usize
+}
+
+impl Iterator for XSDTIter {
+    type Item = usize;
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.i < self.sdt.data_len()/mem::size_of::<u64>() {
+            let item = unsafe { *(self.sdt.data_address() as *const u64).offset(self.i as isize) };
+            self.i += 1;
+            Some(item as usize)
+        } else {
+            None
+        }
+    }
+}