Merge changes I2614e5df,I25f8db10,I97947c38,Ic4eebf81,I1404cab0, ...

* changes:
  pvmfw: Add support for appended configuration data
  pvmfw: Add MemoryTracker & MemorySlices
  pvmfw: Support managing page tables dynamically
  libfdt: Rename Fdt::bytes to Fdt::buffer
  libfdt: Map FDT_ERR_NOTFOUND to Option::None
  libfdt: Extend Rust wrapper with write functions
diff --git a/libs/libfdt/src/lib.rs b/libs/libfdt/src/lib.rs
index 01f7b36..ff1db63 100644
--- a/libs/libfdt/src/lib.rs
+++ b/libs/libfdt/src/lib.rs
@@ -16,6 +16,7 @@
 //! to a bare-metal environment.
 
 #![no_std]
+#![feature(let_else)] // Stabilized in 1.65.0
 
 use core::ffi::{c_int, c_void, CStr};
 use core::fmt;
@@ -136,6 +137,14 @@
     }
 }
 
+fn fdt_err_or_option(val: c_int) -> Result<Option<c_int>> {
+    match fdt_err(val) {
+        Ok(val) => Ok(Some(val)),
+        Err(FdtError::NotFound) => Ok(None),
+        Err(e) => Err(e),
+    }
+}
+
 /// Value of a #address-cells property.
 #[derive(Copy, Clone, Debug)]
 enum AddrCells {
@@ -251,8 +260,8 @@
 }
 
 impl<'a> MemRegIterator<'a> {
-    fn new(reg: RegIterator<'a>) -> Result<Self> {
-        Ok(Self { reg })
+    fn new(reg: RegIterator<'a>) -> Self {
+        Self { reg }
     }
 }
 
@@ -285,45 +294,67 @@
     }
 
     /// Retrieve the standard (deprecated) device_type <string> property.
-    pub fn device_type(&self) -> Result<&CStr> {
+    pub fn device_type(&self) -> Result<Option<&CStr>> {
         self.getprop_str(CStr::from_bytes_with_nul(b"device_type\0").unwrap())
     }
 
     /// Retrieve the standard reg <prop-encoded-array> property.
-    pub fn reg(&self) -> Result<RegIterator<'a>> {
-        let parent = self.parent()?;
+    pub fn reg(&self) -> Result<Option<RegIterator<'a>>> {
+        let reg = CStr::from_bytes_with_nul(b"reg\0").unwrap();
 
-        let addr_cells = parent.address_cells()?;
-        let size_cells = parent.size_cells()?;
-        let cells = self.getprop_cells(CStr::from_bytes_with_nul(b"reg\0").unwrap())?;
+        if let Some(cells) = self.getprop_cells(reg)? {
+            let parent = self.parent()?;
 
-        Ok(RegIterator::new(cells, addr_cells, size_cells))
+            let addr_cells = parent.address_cells()?;
+            let size_cells = parent.size_cells()?;
+
+            Ok(Some(RegIterator::new(cells, addr_cells, size_cells)))
+        } else {
+            Ok(None)
+        }
     }
 
     /// Retrieve the value of a given <string> property.
-    pub fn getprop_str(&self, name: &CStr) -> Result<&CStr> {
-        CStr::from_bytes_with_nul(self.getprop(name)?).map_err(|_| FdtError::BadValue)
+    pub fn getprop_str(&self, name: &CStr) -> Result<Option<&CStr>> {
+        let value = if let Some(bytes) = self.getprop(name)? {
+            Some(CStr::from_bytes_with_nul(bytes).map_err(|_| FdtError::BadValue)?)
+        } else {
+            None
+        };
+        Ok(value)
     }
 
     /// Retrieve the value of a given property as an array of cells.
-    pub fn getprop_cells(&self, name: &CStr) -> Result<CellIterator<'a>> {
-        Ok(CellIterator::new(self.getprop(name)?))
+    pub fn getprop_cells(&self, name: &CStr) -> Result<Option<CellIterator<'a>>> {
+        if let Some(cells) = self.getprop(name)? {
+            Ok(Some(CellIterator::new(cells)))
+        } else {
+            Ok(None)
+        }
     }
 
     /// Retrieve the value of a given <u32> property.
-    pub fn getprop_u32(&self, name: &CStr) -> Result<u32> {
-        let prop = self.getprop(name)?.try_into().map_err(|_| FdtError::BadValue)?;
-        Ok(u32::from_be_bytes(prop))
+    pub fn getprop_u32(&self, name: &CStr) -> Result<Option<u32>> {
+        let value = if let Some(bytes) = self.getprop(name)? {
+            Some(u32::from_be_bytes(bytes.try_into().map_err(|_| FdtError::BadValue)?))
+        } else {
+            None
+        };
+        Ok(value)
     }
 
     /// Retrieve the value of a given <u64> property.
-    pub fn getprop_u64(&self, name: &CStr) -> Result<u64> {
-        let prop = self.getprop(name)?.try_into().map_err(|_| FdtError::BadValue)?;
-        Ok(u64::from_be_bytes(prop))
+    pub fn getprop_u64(&self, name: &CStr) -> Result<Option<u64>> {
+        let value = if let Some(bytes) = self.getprop(name)? {
+            Some(u64::from_be_bytes(bytes.try_into().map_err(|_| FdtError::BadValue)?))
+        } else {
+            None
+        };
+        Ok(value)
     }
 
     /// Retrieve the value of a given property.
-    pub fn getprop(&self, name: &CStr) -> Result<&'a [u8]> {
+    pub fn getprop(&self, name: &CStr) -> Result<Option<&'a [u8]>> {
         let mut len: i32 = 0;
         // SAFETY - Accesses are constrained to the DT totalsize (validated by ctor) and the
         // function respects the passed number of characters.
@@ -337,14 +368,21 @@
                 &mut len as *mut i32,
             )
         } as *const u8;
+
+        let Some(len) = fdt_err_or_option(len)? else {
+            return Ok(None); // Property was not found.
+        };
+        let len = usize::try_from(len).map_err(|_| FdtError::Internal)?;
+
         if prop.is_null() {
-            return fdt_err(len).and(Err(FdtError::Internal));
+            // We expected an error code in len but still received a valid value?!
+            return Err(FdtError::Internal);
         }
-        let len = usize::try_from(fdt_err(len)?).map_err(|_| FdtError::Internal)?;
-        let base =
+
+        let offset =
             (prop as usize).checked_sub(self.fdt.as_ptr() as usize).ok_or(FdtError::Internal)?;
 
-        self.fdt.bytes.get(base..(base + len)).ok_or(FdtError::Internal)
+        Ok(Some(self.fdt.buffer.get(offset..(offset + len)).ok_or(FdtError::Internal)?))
     }
 
     /// Get reference to the containing device tree.
@@ -362,11 +400,7 @@
             )
         };
 
-        match fdt_err(ret) {
-            Ok(offset) => Ok(Some(Self { fdt: self.fdt, offset })),
-            Err(FdtError::NotFound) => Ok(None),
-            Err(e) => Err(e),
-        }
+        Ok(fdt_err_or_option(ret)?.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     fn address_cells(&self) -> Result<AddrCells> {
@@ -384,6 +418,69 @@
     }
 }
 
+/// Mutable FDT node.
+pub struct FdtNodeMut<'a> {
+    fdt: &'a mut Fdt,
+    offset: c_int,
+}
+
+impl<'a> FdtNodeMut<'a> {
+    /// Append a property name-value (possibly empty) pair to the given node.
+    pub fn appendprop<T: AsRef<[u8]>>(&mut self, name: &CStr, value: &T) -> Result<()> {
+        // SAFETY - Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe {
+            libfdt_bindgen::fdt_appendprop(
+                self.fdt.as_mut_ptr(),
+                self.offset,
+                name.as_ptr(),
+                value.as_ref().as_ptr().cast::<c_void>(),
+                value.as_ref().len().try_into().map_err(|_| FdtError::BadValue)?,
+            )
+        };
+
+        fdt_err_expect_zero(ret)
+    }
+
+    /// Append a (address, size) pair property to the given node.
+    pub fn appendprop_addrrange(&mut self, name: &CStr, addr: u64, size: u64) -> Result<()> {
+        // SAFETY - Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe {
+            libfdt_bindgen::fdt_appendprop_addrrange(
+                self.fdt.as_mut_ptr(),
+                self.parent()?.offset,
+                self.offset,
+                name.as_ptr(),
+                addr,
+                size,
+            )
+        };
+
+        fdt_err_expect_zero(ret)
+    }
+
+    /// Get reference to the containing device tree.
+    pub fn fdt(&mut self) -> &mut Fdt {
+        self.fdt
+    }
+
+    /// Add a new subnode to the given node and return it as a FdtNodeMut on success.
+    pub fn add_subnode(&'a mut self, name: &CStr) -> Result<Self> {
+        // SAFETY - Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe {
+            libfdt_bindgen::fdt_add_subnode(self.fdt.as_mut_ptr(), self.offset, name.as_ptr())
+        };
+
+        Ok(Self { fdt: self.fdt, offset: fdt_err(ret)? })
+    }
+
+    fn parent(&'a self) -> Result<FdtNode<'a>> {
+        // SAFETY - Accesses (read-only) are constrained to the DT totalsize.
+        let ret = unsafe { libfdt_bindgen::fdt_parent_offset(self.fdt.as_ptr(), self.offset) };
+
+        Ok(FdtNode { fdt: &*self.fdt, offset: fdt_err(ret)? })
+    }
+}
+
 /// Iterator over nodes sharing a same compatible string.
 pub struct CompatibleIterator<'a> {
     node: FdtNode<'a>,
@@ -411,10 +508,10 @@
     }
 }
 
-/// Wrapper around low-level read-only libfdt functions.
+/// Wrapper around low-level libfdt functions.
 #[repr(transparent)]
 pub struct Fdt {
-    bytes: [u8],
+    buffer: [u8],
 }
 
 impl Fdt {
@@ -428,6 +525,16 @@
         Ok(fdt)
     }
 
+    /// Wraps a mutable slice containing a Flattened Device Tree.
+    ///
+    /// Fails if the FDT does not pass validation.
+    pub fn from_mut_slice(fdt: &mut [u8]) -> Result<&mut Self> {
+        // SAFETY - The FDT will be validated before it is returned.
+        let fdt = unsafe { Self::unchecked_from_mut_slice(fdt) };
+        fdt.check_full()?;
+        Ok(fdt)
+    }
+
     /// Wraps a slice containing a Flattened Device Tree.
     ///
     /// # Safety
@@ -437,35 +544,71 @@
         mem::transmute::<&[u8], &Self>(fdt)
     }
 
+    /// Wraps a mutable slice containing a Flattened Device Tree.
+    ///
+    /// # Safety
+    ///
+    /// The returned FDT might be invalid, only use on slices containing a valid DT.
+    pub unsafe fn unchecked_from_mut_slice(fdt: &mut [u8]) -> &mut Self {
+        mem::transmute::<&mut [u8], &mut Self>(fdt)
+    }
+
+    /// Make the whole slice containing the DT available to libfdt.
+    pub fn unpack(&mut self) -> Result<()> {
+        // SAFETY - "Opens" the DT in-place (supported use-case) by updating its header and
+        // internal structures to make use of the whole self.fdt slice but performs no accesses
+        // outside of it and leaves the DT in a state that will be detected by other functions.
+        let ret = unsafe {
+            libfdt_bindgen::fdt_open_into(
+                self.as_ptr(),
+                self.as_mut_ptr(),
+                self.capacity().try_into().map_err(|_| FdtError::Internal)?,
+            )
+        };
+        fdt_err_expect_zero(ret)
+    }
+
+    /// Pack the DT to take a minimum amount of memory.
+    ///
+    /// Doesn't shrink the underlying memory slice.
+    pub fn pack(&mut self) -> Result<()> {
+        // SAFETY - "Closes" the DT in-place by updating its header and relocating its structs.
+        let ret = unsafe { libfdt_bindgen::fdt_pack(self.as_mut_ptr()) };
+        fdt_err_expect_zero(ret)
+    }
+
     /// Return an iterator of memory banks specified the "/memory" node.
     ///
     /// NOTE: This does not support individual "/memory@XXXX" banks.
-    pub fn memory(&self) -> Result<MemRegIterator> {
+    pub fn memory(&self) -> Result<Option<MemRegIterator>> {
         let memory = CStr::from_bytes_with_nul(b"/memory\0").unwrap();
         let device_type = CStr::from_bytes_with_nul(b"memory\0").unwrap();
 
-        let node = self.node(memory)?;
-        if node.device_type()? != device_type {
-            return Err(FdtError::BadValue);
-        }
+        if let Some(node) = self.node(memory)? {
+            if node.device_type()? != Some(device_type) {
+                return Err(FdtError::BadValue);
+            }
+            let reg = node.reg()?.ok_or(FdtError::BadValue)?;
 
-        MemRegIterator::new(node.reg()?)
+            Ok(Some(MemRegIterator::new(reg)))
+        } else {
+            Ok(None)
+        }
     }
 
     /// Retrieve the standard /chosen node.
-    pub fn chosen(&self) -> Result<FdtNode> {
+    pub fn chosen(&self) -> Result<Option<FdtNode>> {
         self.node(CStr::from_bytes_with_nul(b"/chosen\0").unwrap())
     }
 
     /// Get the root node of the tree.
     pub fn root(&self) -> Result<FdtNode> {
-        self.node(CStr::from_bytes_with_nul(b"/\0").unwrap())
+        self.node(CStr::from_bytes_with_nul(b"/\0").unwrap())?.ok_or(FdtError::Internal)
     }
 
     /// Find a tree node by its full path.
-    pub fn node(&self, path: &CStr) -> Result<FdtNode> {
-        let offset = self.path_offset(path)?;
-        Ok(FdtNode { fdt: self, offset })
+    pub fn node(&self, path: &CStr) -> Result<Option<FdtNode>> {
+        Ok(self.path_offset(path)?.map(|offset| FdtNode { fdt: self, offset }))
     }
 
     /// Iterate over nodes with a given compatible string.
@@ -473,7 +616,17 @@
         CompatibleIterator::new(self, compatible)
     }
 
-    fn path_offset(&self, path: &CStr) -> Result<c_int> {
+    /// Get the mutable root node of the tree.
+    pub fn root_mut(&mut self) -> Result<FdtNodeMut> {
+        self.node_mut(CStr::from_bytes_with_nul(b"/\0").unwrap())?.ok_or(FdtError::Internal)
+    }
+
+    /// Find a mutable tree node by its full path.
+    pub fn node_mut(&mut self, path: &CStr) -> Result<Option<FdtNodeMut>> {
+        Ok(self.path_offset(path)?.map(|offset| FdtNodeMut { fdt: self, offset }))
+    }
+
+    fn path_offset(&self, path: &CStr) -> Result<Option<c_int>> {
         let len = path.to_bytes().len().try_into().map_err(|_| FdtError::BadPath)?;
         // SAFETY - Accesses are constrained to the DT totalsize (validated by ctor) and the
         // function respects the passed number of characters.
@@ -482,11 +635,11 @@
             libfdt_bindgen::fdt_path_offset_namelen(self.as_ptr(), path.as_ptr(), len)
         };
 
-        fdt_err(ret)
+        fdt_err_or_option(ret)
     }
 
     fn check_full(&self) -> Result<()> {
-        let len = self.bytes.len();
+        let len = self.buffer.len();
         // SAFETY - Only performs read accesses within the limits of the slice. If successful, this
         // call guarantees to other unsafe calls that the header contains a valid totalsize (w.r.t.
         // 'len' i.e. the self.fdt slice) that those C functions can use to perform bounds
@@ -499,4 +652,12 @@
     fn as_ptr(&self) -> *const c_void {
         self as *const _ as *const c_void
     }
+
+    fn as_mut_ptr(&mut self) -> *mut c_void {
+        self as *mut _ as *mut c_void
+    }
+
+    fn capacity(&self) -> usize {
+        self.buffer.len()
+    }
 }
diff --git a/pvmfw/Android.bp b/pvmfw/Android.bp
index 77de696..455b214 100644
--- a/pvmfw/Android.bp
+++ b/pvmfw/Android.bp
@@ -12,11 +12,16 @@
         "legacy",
     ],
     rustlibs: [
+        "libaarch64_paging",
         "libbuddy_system_allocator",
+        "liblibfdt",
         "liblog_rust_nostd",
         "libpvmfw_embedded_key",
         "libvmbase",
     ],
+    static_libs: [
+        "libarm-optimized-routines-mem",
+    ],
     apex_available: ["com.android.virt"],
 }
 
diff --git a/pvmfw/idmap.S b/pvmfw/idmap.S
index ec3ceaf..2ef0d42 100644
--- a/pvmfw/idmap.S
+++ b/pvmfw/idmap.S
@@ -40,13 +40,9 @@
 	/* level 1 */
 	.quad		.L_BLOCK_DEV | 0x0		// 1 GB of device mappings
 	.quad		.L_TT_TYPE_TABLE + 0f		// Unmapped device memory, and pVM firmware
-	.quad		.L_TT_TYPE_TABLE + 1f		// up to 1 GB of DRAM
-	.fill		509, 8, 0x0			// 509 GB of remaining VA space
+	.fill		510, 8, 0x0			// 510 GB of remaining VA space
 
 	/* level 2 */
 0:	.fill		510, 8, 0x0
 	.quad		.L_BLOCK_MEM_XIP | 0x7fc00000	// pVM firmware image
 	.quad		.L_BLOCK_MEM	 | 0x7fe00000	// Writable memory for stack, heap &c.
-1:	.quad		.L_BLOCK_RO	 | 0x80000000	// DT provided by VMM
-	.quad		.L_BLOCK_RO	 | 0x80200000	// 2 MB of DRAM containing payload image
-	.fill		510, 8, 0x0
diff --git a/pvmfw/src/config.rs b/pvmfw/src/config.rs
new file mode 100644
index 0000000..0f2a39c
--- /dev/null
+++ b/pvmfw/src/config.rs
@@ -0,0 +1,200 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Support for the pvmfw configuration data format.
+
+use crate::helpers;
+use core::fmt;
+use core::mem;
+use core::num::NonZeroUsize;
+use core::ops;
+use core::result;
+
+#[repr(C, packed)]
+#[derive(Clone, Copy, Debug)]
+struct Header {
+    magic: u32,
+    version: u32,
+    total_size: u32,
+    flags: u32,
+    entries: [HeaderEntry; Entry::COUNT],
+}
+
+#[derive(Debug)]
+pub enum Error {
+    /// Reserved region can't fit configuration header.
+    BufferTooSmall,
+    /// Header doesn't contain the expect magic value.
+    InvalidMagic,
+    /// Version of the header isn't supported.
+    UnsupportedVersion(u16, u16),
+    /// Header sets flags incorrectly or uses reserved flags.
+    InvalidFlags(u32),
+    /// Header describes configuration data that doesn't fit in the expected buffer.
+    InvalidSize(usize),
+    /// Header entry is invalid.
+    InvalidEntry(Entry),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::BufferTooSmall => write!(f, "Reserved region is smaller than config header"),
+            Self::InvalidMagic => write!(f, "Wrong magic number"),
+            Self::UnsupportedVersion(x, y) => write!(f, "Version {x}.{y} not supported"),
+            Self::InvalidFlags(v) => write!(f, "Flags value {v:#x} is incorrect or reserved"),
+            Self::InvalidSize(sz) => write!(f, "Total size ({sz:#x}) overflows reserved region"),
+            Self::InvalidEntry(e) => write!(f, "Entry {e:?} is invalid"),
+        }
+    }
+}
+
+pub type Result<T> = result::Result<T, Error>;
+
+impl Header {
+    const MAGIC: u32 = u32::from_ne_bytes(*b"pvmf");
+    const PADDED_SIZE: usize =
+        helpers::unchecked_align_up(mem::size_of::<Self>(), mem::size_of::<u64>());
+
+    pub const fn version(major: u16, minor: u16) -> u32 {
+        ((major as u32) << 16) | (minor as u32)
+    }
+
+    pub const fn version_tuple(&self) -> (u16, u16) {
+        ((self.version >> 16) as u16, self.version as u16)
+    }
+
+    pub fn total_size(&self) -> usize {
+        self.total_size as usize
+    }
+
+    pub fn body_size(&self) -> usize {
+        self.total_size() - Self::PADDED_SIZE
+    }
+
+    fn get(&self, entry: Entry) -> HeaderEntry {
+        self.entries[entry as usize]
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum Entry {
+    Bcc = 0,
+    DebugPolicy = 1,
+}
+
+impl Entry {
+    const COUNT: usize = 2;
+}
+
+#[repr(packed)]
+#[derive(Clone, Copy, Debug)]
+struct HeaderEntry {
+    offset: u32,
+    size: u32,
+}
+
+impl HeaderEntry {
+    pub fn is_empty(&self) -> bool {
+        self.offset() == 0 && self.size() == 0
+    }
+
+    pub fn fits_in(&self, max_size: usize) -> bool {
+        (Header::PADDED_SIZE..max_size).contains(&self.offset())
+            && NonZeroUsize::new(self.size())
+                .and_then(|s| s.checked_add(self.offset()))
+                .filter(|&x| x.get() <= max_size)
+                .is_some()
+    }
+
+    pub fn as_body_range(&self) -> ops::Range<usize> {
+        let start = self.offset() - Header::PADDED_SIZE;
+
+        start..(start + self.size())
+    }
+
+    pub fn offset(&self) -> usize {
+        self.offset as usize
+    }
+
+    pub fn size(&self) -> usize {
+        self.size as usize
+    }
+}
+
+#[derive(Debug)]
+pub struct Config<'a> {
+    header: &'a Header,
+    body: &'a mut [u8],
+}
+
+impl<'a> Config<'a> {
+    /// Take ownership of a pvmfw configuration consisting of its header and following entries.
+    ///
+    /// SAFETY - 'data' should respect the alignment of Header.
+    pub unsafe fn new(data: &'a mut [u8]) -> Result<Self> {
+        let header = data.get(..Header::PADDED_SIZE).ok_or(Error::BufferTooSmall)?;
+
+        let header = &*(header.as_ptr() as *const Header);
+
+        if header.magic != Header::MAGIC {
+            return Err(Error::InvalidMagic);
+        }
+
+        if header.version != Header::version(1, 0) {
+            let (major, minor) = header.version_tuple();
+            return Err(Error::UnsupportedVersion(major, minor));
+        }
+
+        if header.flags != 0 {
+            return Err(Error::InvalidFlags(header.flags));
+        }
+
+        let total_size = header.total_size();
+
+        // BCC is a mandatory entry of the configuration data.
+        if !header.get(Entry::Bcc).fits_in(total_size) {
+            return Err(Error::InvalidEntry(Entry::Bcc));
+        }
+
+        // Debug policy is optional.
+        let dp = header.get(Entry::DebugPolicy);
+        if !dp.is_empty() && !dp.fits_in(total_size) {
+            return Err(Error::InvalidEntry(Entry::DebugPolicy));
+        }
+
+        let body = data
+            .get_mut(Header::PADDED_SIZE..)
+            .ok_or(Error::BufferTooSmall)?
+            .get_mut(..header.body_size())
+            .ok_or(Error::InvalidSize(total_size))?;
+
+        Ok(Self { header, body })
+    }
+
+    /// Get slice containing the platform BCC.
+    pub fn get_bcc_mut(&mut self) -> &mut [u8] {
+        &mut self.body[self.header.get(Entry::Bcc).as_body_range()]
+    }
+
+    /// Get slice containing the platform debug policy.
+    pub fn get_debug_policy(&mut self) -> Option<&mut [u8]> {
+        let entry = self.header.get(Entry::DebugPolicy);
+        if entry.is_empty() {
+            None
+        } else {
+            Some(&mut self.body[entry.as_body_range()])
+        }
+    }
+}
diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index c0ad878..b840488 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -14,13 +14,20 @@
 
 //! Low-level entry and exit points of pvmfw.
 
+use crate::config;
+use crate::fdt;
 use crate::heap;
 use crate::helpers;
+use crate::memory::MemoryTracker;
 use crate::mmio_guard;
+use crate::mmu;
 use core::arch::asm;
+use core::num::NonZeroUsize;
 use core::slice;
 use log::debug;
 use log::error;
+use log::info;
+use log::warn;
 use log::LevelFilter;
 use vmbase::{console, layout, logger, main, power::reboot};
 
@@ -28,8 +35,16 @@
 enum RebootReason {
     /// A malformed BCC was received.
     InvalidBcc,
+    /// An invalid configuration was appended to pvmfw.
+    InvalidConfig,
     /// An unexpected internal error happened.
     InternalError,
+    /// The provided FDT was invalid.
+    InvalidFdt,
+    /// The provided payload was invalid.
+    InvalidPayload,
+    /// The provided ramdisk was invalid.
+    InvalidRamdisk,
 }
 
 main!(start);
@@ -48,6 +63,98 @@
     // if we reach this point and return, vmbase::entry::rust_entry() will call power::shutdown().
 }
 
+struct MemorySlices<'a> {
+    fdt: &'a mut libfdt::Fdt,
+    kernel: &'a [u8],
+    ramdisk: Option<&'a [u8]>,
+}
+
+impl<'a> MemorySlices<'a> {
+    fn new(
+        fdt: usize,
+        payload: usize,
+        payload_size: usize,
+        memory: &mut MemoryTracker,
+    ) -> Result<Self, RebootReason> {
+        // SAFETY - SIZE_2MB is non-zero.
+        const FDT_SIZE: NonZeroUsize = unsafe { NonZeroUsize::new_unchecked(helpers::SIZE_2MB) };
+        // TODO - Only map the FDT as read-only, until we modify it right before jump_to_payload()
+        // e.g. by generating a DTBO for a template DT in main() and, on return, re-map DT as RW,
+        // overwrite with the template DT and apply the DTBO.
+        let range = memory.alloc_mut(fdt, FDT_SIZE).map_err(|e| {
+            error!("Failed to allocate the FDT range: {e}");
+            RebootReason::InternalError
+        })?;
+
+        // SAFETY - The tracker validated the range to be in main memory, mapped, and not overlap.
+        let fdt = unsafe { slice::from_raw_parts_mut(range.start as *mut u8, range.len()) };
+        let fdt = libfdt::Fdt::from_mut_slice(fdt).map_err(|e| {
+            error!("Failed to spawn the FDT wrapper: {e}");
+            RebootReason::InvalidFdt
+        })?;
+
+        debug!("Fdt passed validation!");
+
+        let memory_range = fdt
+            .memory()
+            .map_err(|e| {
+                error!("Failed to get /memory from the DT: {e}");
+                RebootReason::InvalidFdt
+            })?
+            .ok_or_else(|| {
+                error!("Node /memory was found empty");
+                RebootReason::InvalidFdt
+            })?
+            .next()
+            .ok_or_else(|| {
+                error!("Failed to read the memory size from the FDT");
+                RebootReason::InternalError
+            })?;
+
+        debug!("Resizing MemoryTracker to range {memory_range:#x?}");
+
+        memory.shrink(&memory_range).map_err(|_| {
+            error!("Failed to use memory range value from DT: {memory_range:#x?}");
+            RebootReason::InvalidFdt
+        })?;
+
+        let payload_size = NonZeroUsize::new(payload_size).ok_or_else(|| {
+            error!("Invalid payload size: {payload_size:#x}");
+            RebootReason::InvalidPayload
+        })?;
+
+        let payload_range = memory.alloc(payload, payload_size).map_err(|e| {
+            error!("Failed to obtain the payload range: {e}");
+            RebootReason::InternalError
+        })?;
+        // SAFETY - The tracker validated the range to be in main memory, mapped, and not overlap.
+        let kernel =
+            unsafe { slice::from_raw_parts(payload_range.start as *const u8, payload_range.len()) };
+
+        let ramdisk_range = fdt::initrd_range(fdt).map_err(|e| {
+            error!("An error occurred while locating the ramdisk in the device tree: {e}");
+            RebootReason::InternalError
+        })?;
+
+        let ramdisk = if let Some(r) = ramdisk_range {
+            debug!("Located ramdisk at {r:?}");
+            let r = memory.alloc_range(&r).map_err(|e| {
+                error!("Failed to obtain the initrd range: {e}");
+                RebootReason::InvalidRamdisk
+            })?;
+
+            // SAFETY - The region was validated by memory to be in main memory, mapped, and
+            // not overlap.
+            Some(unsafe { slice::from_raw_parts(r.start as *const u8, r.len()) })
+        } else {
+            info!("Couldn't locate the ramdisk from the device tree");
+            None
+        };
+
+        Ok(Self { fdt, kernel, ramdisk })
+    }
+}
+
 /// Sets up the environment for main() and wraps its result for start().
 ///
 /// Provide the abstractions necessary for start() to abort the pVM boot and for main() to run with
@@ -63,14 +170,6 @@
 
     logger::init(LevelFilter::Info).map_err(|_| RebootReason::InternalError)?;
 
-    const FDT_MAX_SIZE: usize = helpers::SIZE_2MB;
-    // TODO: Check that the FDT is fully contained in RAM.
-    // SAFETY - We trust the VMM, for now.
-    let fdt = unsafe { slice::from_raw_parts_mut(fdt as *mut u8, FDT_MAX_SIZE) };
-    // TODO: Check that the payload is fully contained in RAM and doesn't overlap with the FDT.
-    // SAFETY - We trust the VMM, for now.
-    let payload = unsafe { slice::from_raw_parts(payload as *const u8, payload_size) };
-
     // Use debug!() to avoid printing to the UART if we failed to configure it as only local
     // builds that have tweaked the logger::init() call will actually attempt to log the message.
 
@@ -86,13 +185,45 @@
 
     // SAFETY - We only get the appended payload from here, once. It is mapped and the linker
     // script prevents it from overlapping with other objects.
-    let bcc = as_bcc(unsafe { get_appended_data_slice() }).ok_or_else(|| {
+    let appended_data = unsafe { get_appended_data_slice() };
+
+    // Up to this point, we were using the built-in static (from .rodata) page tables.
+
+    let mut page_table = mmu::PageTable::from_static_layout().map_err(|e| {
+        error!("Failed to set up the dynamic page tables: {e}");
+        RebootReason::InternalError
+    })?;
+
+    const CONSOLE_LEN: usize = 1; // vmbase::uart::Uart only uses one u8 register.
+    let uart_range = console::BASE_ADDRESS..(console::BASE_ADDRESS + CONSOLE_LEN);
+    page_table.map_device(&uart_range).map_err(|e| {
+        error!("Failed to remap the UART as a dynamic page table entry: {e}");
+        RebootReason::InternalError
+    })?;
+
+    // SAFETY - We only get the appended payload from here, once. It is statically mapped and the
+    // linker script prevents it from overlapping with other objects.
+    let mut appended = unsafe { AppendedPayload::new(appended_data) }.ok_or_else(|| {
+        error!("No valid configuration found");
+        RebootReason::InvalidConfig
+    })?;
+
+    let bcc = appended.get_bcc_mut().ok_or_else(|| {
         error!("Invalid BCC");
         RebootReason::InvalidBcc
     })?;
 
+    debug!("Activating dynamic page table...");
+    // SAFETY - page_table duplicates the static mappings for everything that the Rust code is
+    // aware of so activating it shouldn't have any visible effect.
+    unsafe { page_table.activate() };
+    debug!("... Success!");
+
+    let mut memory = MemoryTracker::new(page_table);
+    let slices = MemorySlices::new(fdt, payload, payload_size, &mut memory)?;
+
     // This wrapper allows main() to be blissfully ignorant of platform details.
-    crate::main(fdt, payload, bcc);
+    crate::main(slices.fdt, slices.kernel, slices.ramdisk, bcc);
 
     // TODO: Overwrite BCC before jumping to payload to avoid leaking our sealing key.
 
@@ -169,13 +300,50 @@
     slice::from_raw_parts_mut(base as *mut u8, size)
 }
 
-fn as_bcc(data: &mut [u8]) -> Option<&mut [u8]> {
-    const BCC_SIZE: usize = helpers::SIZE_4KB;
+enum AppendedPayload<'a> {
+    /// Configuration data.
+    Config(config::Config<'a>),
+    /// Deprecated raw BCC, as used in Android T.
+    LegacyBcc(&'a mut [u8]),
+}
 
-    if cfg!(feature = "legacy") {
+impl<'a> AppendedPayload<'a> {
+    /// SAFETY - 'data' should respect the alignment of config::Header.
+    unsafe fn new(data: &'a mut [u8]) -> Option<Self> {
+        if Self::is_valid_config(data) {
+            Some(Self::Config(config::Config::new(data).unwrap()))
+        } else if cfg!(feature = "legacy") {
+            const BCC_SIZE: usize = helpers::SIZE_4KB;
+            warn!("Assuming the appended data at {:?} to be a raw BCC", data.as_ptr());
+            Some(Self::LegacyBcc(&mut data[..BCC_SIZE]))
+        } else {
+            None
+        }
+    }
+
+    unsafe fn is_valid_config(data: &mut [u8]) -> bool {
+        // This function is necessary to prevent the borrow checker from getting confused
+        // about the ownership of data in new(); see https://users.rust-lang.org/t/78467.
+        let addr = data.as_ptr();
+        config::Config::new(data)
+            .map_err(|e| warn!("Invalid configuration data at {addr:?}: {e}"))
+            .is_ok()
+    }
+
+    #[allow(dead_code)] // TODO(b/232900974)
+    fn get_debug_policy(&mut self) -> Option<&mut [u8]> {
+        match self {
+            Self::Config(ref mut cfg) => cfg.get_debug_policy(),
+            Self::LegacyBcc(_) => None,
+        }
+    }
+
+    fn get_bcc_mut(&mut self) -> Option<&mut [u8]> {
+        let bcc = match self {
+            Self::LegacyBcc(ref mut bcc) => bcc,
+            Self::Config(ref mut cfg) => cfg.get_bcc_mut(),
+        };
         // TODO(b/256148034): return None if BccHandoverParse(bcc) != kDiceResultOk.
-        Some(&mut data[..BCC_SIZE])
-    } else {
-        None
+        Some(bcc)
     }
 }
diff --git a/pvmfw/src/fdt.rs b/pvmfw/src/fdt.rs
new file mode 100644
index 0000000..5b9efd2
--- /dev/null
+++ b/pvmfw/src/fdt.rs
@@ -0,0 +1,32 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! High-level FDT functions.
+
+use core::ffi::CStr;
+use core::ops::Range;
+
+/// Extract from /chosen the address range containing the pre-loaded ramdisk.
+pub fn initrd_range(fdt: &libfdt::Fdt) -> libfdt::Result<Option<Range<usize>>> {
+    let start = CStr::from_bytes_with_nul(b"linux,initrd-start\0").unwrap();
+    let end = CStr::from_bytes_with_nul(b"linux,initrd-end\0").unwrap();
+
+    if let Some(chosen) = fdt.chosen()? {
+        if let (Some(start), Some(end)) = (chosen.getprop_u32(start)?, chosen.getprop_u32(end)?) {
+            return Ok(Some((start as usize)..(end as usize)));
+        }
+    }
+
+    Ok(None)
+}
diff --git a/pvmfw/src/helpers.rs b/pvmfw/src/helpers.rs
index 59cf9f3..ead8bb4 100644
--- a/pvmfw/src/helpers.rs
+++ b/pvmfw/src/helpers.rs
@@ -14,6 +14,8 @@
 
 //! Miscellaneous helper functions.
 
+use core::arch::asm;
+
 pub const SIZE_4KB: usize = 4 << 10;
 pub const SIZE_2MB: usize = 2 << 20;
 
@@ -24,6 +26,13 @@
     addr & !(alignment - 1)
 }
 
+/// Computes the smallest multiple of the provided alignment larger or equal to the address.
+///
+/// Note: the result is undefined if alignment isn't a power of two and may wrap to 0.
+pub const fn unchecked_align_up(addr: usize, alignment: usize) -> usize {
+    unchecked_align_down(addr + alignment - 1, alignment)
+}
+
 /// Safe wrapper around unchecked_align_up() that validates its assumptions and doesn't wrap.
 pub const fn align_up(addr: usize, alignment: usize) -> Option<usize> {
     if !alignment.is_power_of_two() {
@@ -39,3 +48,30 @@
 pub const fn page_4kb_of(addr: usize) -> usize {
     unchecked_align_down(addr, SIZE_4KB)
 }
+
+#[inline]
+fn min_dcache_line_size() -> usize {
+    const DMINLINE_SHIFT: usize = 16;
+    const DMINLINE_MASK: usize = 0xf;
+    let ctr_el0: usize;
+
+    unsafe { asm!("mrs {x}, ctr_el0", x = out(reg) ctr_el0) }
+
+    // DminLine: log2 of the number of words in the smallest cache line of all the data caches.
+    let dminline = (ctr_el0 >> DMINLINE_SHIFT) & DMINLINE_MASK;
+
+    1 << dminline
+}
+
+#[inline]
+/// Flush data cache over the entire slice.
+pub fn flush_region(start: usize, size: usize) {
+    let line_size = min_dcache_line_size();
+    let end = start + size;
+    let start = unchecked_align_down(start, line_size);
+
+    for line in (start..end).step_by(line_size) {
+        // SAFETY - Clearing cache lines shouldn't have Rust-visible side effects.
+        unsafe { asm!("dc cvau, {x}", x = in(reg) line) }
+    }
+}
diff --git a/pvmfw/src/main.rs b/pvmfw/src/main.rs
index 8178d0b..6810fda 100644
--- a/pvmfw/src/main.rs
+++ b/pvmfw/src/main.rs
@@ -17,26 +17,32 @@
 #![no_main]
 #![no_std]
 #![feature(default_alloc_error_handler)]
+#![feature(ptr_const_cast)] // Stabilized in 1.65.0
 
 mod avb;
+mod config;
 mod entry;
 mod exceptions;
+mod fdt;
 mod heap;
 mod helpers;
+mod memory;
 mod mmio_guard;
+mod mmu;
 mod smccc;
 
 use avb::PUBLIC_KEY;
 use log::{debug, info};
 
-fn main(fdt: &mut [u8], payload: &[u8], bcc: &[u8]) {
+fn main(fdt: &libfdt::Fdt, signed_kernel: &[u8], ramdisk: Option<&[u8]>, bcc: &[u8]) {
     info!("pVM firmware");
-    debug!(
-        "fdt_address={:#018x}, payload_start={:#018x}, payload_size={:#018x}",
-        fdt.as_ptr() as usize,
-        payload.as_ptr() as usize,
-        payload.len(),
-    );
+    debug!("FDT: {:?}", fdt as *const libfdt::Fdt);
+    debug!("Signed kernel: {:?} ({:#x} bytes)", signed_kernel.as_ptr(), signed_kernel.len());
+    if let Some(rd) = ramdisk {
+        debug!("Ramdisk: {:?} ({:#x} bytes)", rd.as_ptr(), rd.len());
+    } else {
+        debug!("Ramdisk: None");
+    }
     debug!("BCC: {:?} ({:#x} bytes)", bcc.as_ptr(), bcc.len());
     debug!("AVB public key: addr={:?}, size={:#x} ({1})", PUBLIC_KEY.as_ptr(), PUBLIC_KEY.len());
     info!("Starting payload...");
diff --git a/pvmfw/src/memory.rs b/pvmfw/src/memory.rs
new file mode 100644
index 0000000..0f1892d
--- /dev/null
+++ b/pvmfw/src/memory.rs
@@ -0,0 +1,205 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Low-level allocation and tracking of main memory.
+
+use crate::helpers;
+use crate::mmu;
+use core::cmp::max;
+use core::cmp::min;
+use core::fmt;
+use core::mem;
+use core::mem::MaybeUninit;
+use core::num::NonZeroUsize;
+use core::ops::Range;
+use core::result;
+use log::error;
+
+type MemoryRange = Range<usize>;
+
+#[derive(Clone, Copy, Debug)]
+enum MemoryType {
+    ReadOnly,
+    ReadWrite,
+}
+
+#[derive(Clone, Debug)]
+struct MemoryRegion {
+    range: MemoryRange,
+    mem_type: MemoryType,
+}
+
+impl MemoryRegion {
+    /// True if the instance overlaps with the passed range.
+    pub fn overlaps(&self, range: &MemoryRange) -> bool {
+        let our: &MemoryRange = self.as_ref();
+        max(our.start, range.start) < min(our.end, range.end)
+    }
+
+    /// True if the instance is fully contained within the passed range.
+    pub fn is_within(&self, range: &MemoryRange) -> bool {
+        let our: &MemoryRange = self.as_ref();
+        self.as_ref() == &(max(our.start, range.start)..min(our.end, range.end))
+    }
+}
+
+impl AsRef<MemoryRange> for MemoryRegion {
+    fn as_ref(&self) -> &MemoryRange {
+        &self.range
+    }
+}
+
+/// Tracks non-overlapping slices of main memory.
+pub struct MemoryTracker {
+    // TODO: Use tinyvec::ArrayVec
+    count: usize,
+    regions: [MaybeUninit<MemoryRegion>; MemoryTracker::CAPACITY],
+    total: MemoryRange,
+    page_table: mmu::PageTable,
+}
+
+/// Errors for MemoryTracker operations.
+#[derive(Debug, Clone)]
+pub enum MemoryTrackerError {
+    /// Tried to modify the memory base address.
+    DifferentBaseAddress,
+    /// Tried to shrink to a larger memory size.
+    SizeTooLarge,
+    /// Tracked regions would not fit in memory size.
+    SizeTooSmall,
+    /// Reached limit number of tracked regions.
+    Full,
+    /// Region is out of the tracked memory address space.
+    OutOfRange,
+    /// New region overlaps with tracked regions.
+    Overlaps,
+    /// Region couldn't be mapped.
+    FailedToMap,
+}
+
+impl fmt::Display for MemoryTrackerError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::DifferentBaseAddress => write!(f, "Received different base address"),
+            Self::SizeTooLarge => write!(f, "Tried to shrink to a larger memory size"),
+            Self::SizeTooSmall => write!(f, "Tracked regions would not fit in memory size"),
+            Self::Full => write!(f, "Reached limit number of tracked regions"),
+            Self::OutOfRange => write!(f, "Region is out of the tracked memory address space"),
+            Self::Overlaps => write!(f, "New region overlaps with tracked regions"),
+            Self::FailedToMap => write!(f, "Failed to map the new region"),
+        }
+    }
+}
+
+type Result<T> = result::Result<T, MemoryTrackerError>;
+
+impl MemoryTracker {
+    const CAPACITY: usize = 5;
+    /// Base of the system's contiguous "main" memory.
+    const BASE: usize = 0x8000_0000;
+    /// First address that can't be translated by a level 1 TTBR0_EL1.
+    const MAX_ADDR: usize = 1 << 39;
+
+    /// Create a new instance from an active page table, covering the maximum RAM size.
+    pub fn new(page_table: mmu::PageTable) -> Self {
+        Self {
+            total: Self::BASE..Self::MAX_ADDR,
+            count: 0,
+            page_table,
+            // SAFETY - MaybeUninit items (of regions) do not require initialization.
+            regions: unsafe { MaybeUninit::uninit().assume_init() },
+        }
+    }
+
+    /// Resize the total RAM size.
+    ///
+    /// This function fails if it contains regions that are not included within the new size.
+    pub fn shrink(&mut self, range: &MemoryRange) -> Result<()> {
+        if range.start != self.total.start {
+            return Err(MemoryTrackerError::DifferentBaseAddress);
+        }
+        if self.total.end < range.end {
+            return Err(MemoryTrackerError::SizeTooLarge);
+        }
+        if !self.regions().iter().all(|r| r.is_within(range)) {
+            return Err(MemoryTrackerError::SizeTooSmall);
+        }
+
+        self.total = range.clone();
+        Ok(())
+    }
+
+    /// Allocate the address range for a const slice; returns None if failed.
+    pub fn alloc_range(&mut self, range: &MemoryRange) -> Result<MemoryRange> {
+        self.page_table.map_rodata(range).map_err(|e| {
+            error!("Error during range allocation: {e}");
+            MemoryTrackerError::FailedToMap
+        })?;
+        self.add(MemoryRegion { range: range.clone(), mem_type: MemoryType::ReadOnly })
+    }
+
+    /// Allocate the address range for a mutable slice; returns None if failed.
+    pub fn alloc_range_mut(&mut self, range: &MemoryRange) -> Result<MemoryRange> {
+        self.page_table.map_data(range).map_err(|e| {
+            error!("Error during mutable range allocation: {e}");
+            MemoryTrackerError::FailedToMap
+        })?;
+        self.add(MemoryRegion { range: range.clone(), mem_type: MemoryType::ReadWrite })
+    }
+
+    /// Allocate the address range for a const slice; returns None if failed.
+    pub fn alloc(&mut self, base: usize, size: NonZeroUsize) -> Result<MemoryRange> {
+        self.alloc_range(&(base..(base + size.get())))
+    }
+
+    /// Allocate the address range for a mutable slice; returns None if failed.
+    pub fn alloc_mut(&mut self, base: usize, size: NonZeroUsize) -> Result<MemoryRange> {
+        self.alloc_range_mut(&(base..(base + size.get())))
+    }
+
+    fn regions(&self) -> &[MemoryRegion] {
+        // SAFETY - The first self.count regions have been properly initialized.
+        unsafe { mem::transmute::<_, &[MemoryRegion]>(&self.regions[..self.count]) }
+    }
+
+    fn add(&mut self, region: MemoryRegion) -> Result<MemoryRange> {
+        if !region.is_within(&self.total) {
+            return Err(MemoryTrackerError::OutOfRange);
+        }
+        if self.regions().iter().any(|r| r.overlaps(region.as_ref())) {
+            return Err(MemoryTrackerError::Overlaps);
+        }
+        if self.regions.len() == self.count {
+            return Err(MemoryTrackerError::Full);
+        }
+
+        let region = self.regions[self.count].write(region);
+        self.count += 1;
+        Ok(region.as_ref().clone())
+    }
+}
+
+impl Drop for MemoryTracker {
+    fn drop(&mut self) {
+        for region in self.regions().iter() {
+            match region.mem_type {
+                MemoryType::ReadWrite => {
+                    // TODO: Use page table's dirty bit to only flush pages that were touched.
+                    helpers::flush_region(region.range.start, region.range.len())
+                }
+                MemoryType::ReadOnly => {}
+            }
+        }
+    }
+}
diff --git a/pvmfw/src/mmu.rs b/pvmfw/src/mmu.rs
new file mode 100644
index 0000000..fa94e85
--- /dev/null
+++ b/pvmfw/src/mmu.rs
@@ -0,0 +1,86 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Memory management.
+
+use crate::helpers;
+use aarch64_paging::idmap::IdMap;
+use aarch64_paging::paging::Attributes;
+use aarch64_paging::paging::MemoryRegion;
+use aarch64_paging::MapError;
+use core::ops::Range;
+use vmbase::layout;
+
+// We assume that:
+// - MAIR_EL1.Attr0 = "Device-nGnRE memory" (0b0000_0100)
+// - MAIR_EL1.Attr1 = "Normal memory, Outer & Inner WB Non-transient, R/W-Allocate" (0b1111_1111)
+const MEMORY: Attributes = Attributes::NORMAL.union(Attributes::NON_GLOBAL);
+const DEVICE: Attributes = Attributes::DEVICE_NGNRE.union(Attributes::EXECUTE_NEVER);
+const CODE: Attributes = MEMORY.union(Attributes::READ_ONLY);
+const DATA: Attributes = MEMORY.union(Attributes::EXECUTE_NEVER);
+const RODATA: Attributes = DATA.union(Attributes::READ_ONLY);
+
+/// High-level API for managing MMU mappings.
+pub struct PageTable {
+    idmap: IdMap,
+}
+
+fn appended_payload_range() -> Range<usize> {
+    let start = helpers::align_up(layout::binary_end(), helpers::SIZE_4KB).unwrap();
+    // pvmfw is contained in a 2MiB region so the payload can't be larger than the 2MiB alignment.
+    let end = helpers::align_up(start, helpers::SIZE_2MB).unwrap();
+
+    start..end
+}
+
+impl PageTable {
+    const ASID: usize = 1;
+    const ROOT_LEVEL: usize = 1;
+
+    /// Creates an instance pre-populated with pvmfw's binary layout.
+    pub fn from_static_layout() -> Result<Self, MapError> {
+        let mut page_table = Self { idmap: IdMap::new(Self::ASID, Self::ROOT_LEVEL) };
+
+        page_table.map_code(&layout::text_range())?;
+        page_table.map_data(&layout::writable_region())?;
+        page_table.map_rodata(&layout::rodata_range())?;
+        page_table.map_data(&appended_payload_range())?;
+
+        Ok(page_table)
+    }
+
+    pub unsafe fn activate(&mut self) {
+        self.idmap.activate()
+    }
+
+    pub fn map_device(&mut self, range: &Range<usize>) -> Result<(), MapError> {
+        self.map_range(range, DEVICE)
+    }
+
+    pub fn map_data(&mut self, range: &Range<usize>) -> Result<(), MapError> {
+        self.map_range(range, DATA)
+    }
+
+    pub fn map_code(&mut self, range: &Range<usize>) -> Result<(), MapError> {
+        self.map_range(range, CODE)
+    }
+
+    pub fn map_rodata(&mut self, range: &Range<usize>) -> Result<(), MapError> {
+        self.map_range(range, RODATA)
+    }
+
+    fn map_range(&mut self, range: &Range<usize>, attr: Attributes) -> Result<(), MapError> {
+        self.idmap.map_range(&MemoryRegion::new(range.start, range.end), attr)
+    }
+}
diff --git a/vmbase/example/idmap.S b/vmbase/example/idmap.S
index 7fc5d5e..71a6ade 100644
--- a/vmbase/example/idmap.S
+++ b/vmbase/example/idmap.S
@@ -44,7 +44,7 @@
 	.fill		509, 8, 0x0			// 509 GiB of remaining VA space
 
 	/* level 2 */
-0:	.quad		.L_BLOCK_RO  | 0x80000000	// DT provided by VMM
+0:	.quad		.L_BLOCK_MEM | 0x80000000	// DT provided by VMM
 	.quad		.L_BLOCK_MEM_XIP | 0x80200000	// 2 MiB of DRAM containing image
 	.quad		.L_BLOCK_MEM | 0x80400000	// 2 MiB of writable DRAM
 	.fill		509, 8, 0x0
diff --git a/vmbase/example/src/main.rs b/vmbase/example/src/main.rs
index dcff6e1..bb64651 100644
--- a/vmbase/example/src/main.rs
+++ b/vmbase/example/src/main.rs
@@ -151,17 +151,41 @@
 
     let reader = Fdt::from_slice(fdt).unwrap();
     info!("FDT passed verification.");
-    for reg in reader.memory().unwrap() {
+    for reg in reader.memory().unwrap().unwrap() {
         info!("memory @ {reg:#x?}");
     }
 
     let compatible = CStr::from_bytes_with_nul(b"ns16550a\0").unwrap();
 
     for c in reader.compatible_nodes(compatible).unwrap() {
-        let reg = c.reg().unwrap().next().unwrap();
+        let reg = c.reg().unwrap().unwrap().next().unwrap();
         info!("node compatible with '{}' at {reg:?}", compatible.to_str().unwrap());
     }
 
+    let writer = Fdt::from_mut_slice(fdt).unwrap();
+    writer.unpack().unwrap();
+    info!("FDT successfully unpacked.");
+
+    let path = CStr::from_bytes_with_nul(b"/memory\0").unwrap();
+    let mut node = writer.node_mut(path).unwrap().unwrap();
+    let name = CStr::from_bytes_with_nul(b"child\0").unwrap();
+    let mut child = node.add_subnode(name).unwrap();
+    info!("Created subnode '{}/{}'.", path.to_str().unwrap(), name.to_str().unwrap());
+
+    let name = CStr::from_bytes_with_nul(b"str-property\0").unwrap();
+    child.appendprop(name, b"property-value\0").unwrap();
+    info!("Appended property '{}'.", name.to_str().unwrap());
+
+    let name = CStr::from_bytes_with_nul(b"pair-property\0").unwrap();
+    let addr = 0x0123_4567u64;
+    let size = 0x89ab_cdefu64;
+    child.appendprop_addrrange(name, addr, size).unwrap();
+    info!("Appended property '{}'.", name.to_str().unwrap());
+
+    let writer = child.fdt();
+    writer.pack().unwrap();
+    info!("FDT successfully packed.");
+
     info!("FDT checks done.");
 }