diff --git a/vintfdata/Android.mk b/vintfdata/Android.mk
index d873e29..a7721c2 100644
--- a/vintfdata/Android.mk
+++ b/vintfdata/Android.mk
@@ -128,3 +128,5 @@
 SYSTEM_EXT_MANIFEST_INPUT_FILES :=
 DEVICE_MATRIX_INPUT_FILE :=
 PRODUCT_MANIFEST_INPUT_FILES :=
+
+VINTF_FRAMEWORK_MANIFEST_FROZEN_DIR := $(LOCAL_PATH)/frozen
diff --git a/vintfdata/README.md b/vintfdata/README.md
new file mode 100644
index 0000000..cfc1da7
--- /dev/null
+++ b/vintfdata/README.md
@@ -0,0 +1,91 @@
+# Updating the latest framework manifest
+
+## Adding new HALs / Major version update
+
+Add a new `<hal>` entry without a `max-level` attribute. The `<hal>` entry can
+be added to the main manifest under `manifest.xml`, or to the manifest
+fragment for the server module specified in `vintf_fragments`.
+
+Introducing new HALs are backwards compatible.
+
+## Minor version update
+
+When a framework HAL updates its minor version, simply update the `<version>` or
+`<fqname>` field to the latest version. This is the same as any other HALs.
+
+For example, when `IServiceManager` updates to 1.2, change its `<fqname>` field
+to `@1.2::IServiceManager/default`.
+
+Because minor version updates are backwards compatible, all devices that require
+a lower minor version of the HAL are still compatible.
+
+Leave `max-level` attribute empty.
+
+## Deprecating HAL
+
+When a framework HAL is deprecated, set `max-level` field of the HAL from empty
+to the last frozen version.
+For example, if IDisplayService is deprecated in Android S, set `max-level` to
+Android R (5):
+
+```xml
+<manifest version="3.0" type="framework">
+  <hal format="hidl" max-level="5"> <!-- Level::R -->
+    <name>android.frameworks.displayservice</name>
+    <transport>hwbinder</transport>
+    <fqname>@1.0::IDisplayService/default</fqname>
+  </hal>
+</manifest>
+```
+
+Note that the `max-level` of the HAL is set to Android R, meaning that the HAL
+is last available in Android R and disabled in Android S.
+
+Deprecating a HAL doesn’t mean dropping support of the HAL, so no devices will
+break.
+
+When setting `max-level` of a HAL:
+- If `optional="false"` in frozen DCMs, the build system checks that adding the
+  attribute does not break backwards compatibility; that is,
+  `max-level > last_frozen_level`.
+- If `optional="true"`, the check is disabled. Care must be taken to ensure
+  `max-level` is set appropriately.
+
+## Removing HAL
+
+When the framework drops support of a certain HAL, the corresponding HAL entry
+is removed from the framework manifest, and code that serves and registers the
+HAL must be removed simultaneously.
+
+Devices that are lower than the `max-level` attribute of the HAL may start to
+break if they require this HAL. Hence, this must only be done when there is
+enough evidence that the devices are not updateable to the latest Android
+release.
+
+# Freezing framework HAL manifest
+
+First, check `libvintf` or `hardware/interfaces/compatibility_matrices` to
+determine the current level.
+
+Execute the following, replacing the argument with the level to freeze:
+
+```shell script
+lunch cf_x86_phone-userdebug # or any generic target
+LEVEL=5
+./freeze.sh ${LEVEL}
+```
+
+A new file, `frozen/${LEVEL}.xml`, will be created after the command is
+executed. Frozen system manifests are stored in compatibility matrices. Then,
+manually inspect the frozen compatibility matrix. Modify the `optional`
+field for certain HALs. See comments in the compatibility matrix of the previous
+level for details.
+
+These compatibility matrices served as a reference for devices at that
+target FCM version. Devices at the given target FCM version should
+reference DCMs in the `frozen/` dir, with some of the HALs marked
+as `optional="true"` or even omitted if unused by device-specific code.
+
+At build time, compatibiltiy is checked between framework manifest and
+the respective frozen DCM. HALs in the framework manifest with `max-level`
+less than the specified level are omitted.
diff --git a/vintfdata/freeze.sh b/vintfdata/freeze.sh
new file mode 100755
index 0000000..a624ee3
--- /dev/null
+++ b/vintfdata/freeze.sh
@@ -0,0 +1,42 @@
+#!/bin/bash
+
+mydir="$(dirname $0)"
+
+function freeze() {
+  [[ $# == 1 ]] || {
+    echo "usage: freeze.sh <level>"
+    echo "e.g. To freeze framework manifest for Android R, run:"
+    echo "  freeze.sh 5"
+    return 1
+  }
+  local level="$1"
+  [[ "${ANDROID_BUILD_TOP}" ]] || {
+    echo "ANDROID_BUILD_TOP is not set; did you run envsetup.sh?"
+    return 1
+  }
+  [[ "${ANDROID_HOST_OUT}" ]] || {
+    echo "ANDROID_HOST_OUT is not set; did you run envsetup.sh?"
+    return 1
+  }
+
+  local modules_to_build=check-vintf-all
+  echo "Building ${modules_to_build}"
+  "${ANDROID_BUILD_TOP}/build/soong/soong_ui.bash" --build-mode --all-modules --dir="$(pwd)" ${modules_to_build} || {
+    echo "${modules_to_build} failed. Backwards compatibility might be broken."
+    echo "Check framework manifest changes. If this is intentional, run "
+    echo "  \`vintffm --update\` with appropriate options to update frozen files."
+    return 1
+  }
+
+  echo "Updating level ${level}"
+  "${ANDROID_HOST_OUT}/bin/vintffm" --update --level "${level}" --dirmap "/system:${ANDROID_PRODUCT_OUT}/system" "${mydir}/frozen" || return 1
+
+  local files_to_diff="$(printf "${mydir}/frozen/%s\n" $(ls -1 -t -r ${mydir}/frozen | xargs -I{} basename {} | grep -B1 "${level}.xml"))"
+
+  echo
+  echo "Summary of changes:"
+  echo diff ${files_to_diff}
+  diff ${files_to_diff} || true
+}
+
+freeze $@
diff --git a/vintfdata/frozen/5.xml b/vintfdata/frozen/5.xml
new file mode 100644
index 0000000..71060ec
--- /dev/null
+++ b/vintfdata/frozen/5.xml
@@ -0,0 +1,113 @@
+<compatibility-matrix version="3.0" type="device">
+    <!--
+         cameraserver is installed for all phones and tablets, but not
+         auto or TV.
+    -->
+    <hal format="hidl" optional="true">
+        <name>android.frameworks.cameraservice.service</name>
+        <version>2.1</version>
+        <interface>
+            <name>ICameraService</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.frameworks.displayservice</name>
+        <version>1.0</version>
+        <interface>
+            <name>IDisplayService</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.frameworks.schedulerservice</name>
+        <version>1.0</version>
+        <interface>
+            <name>ISchedulingPolicyService</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.frameworks.sensorservice</name>
+        <version>1.0</version>
+        <interface>
+            <name>ISensorManager</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <!-- TODO(b/171424919) set to required once trusty installs it. -->
+    <hal format="hidl" optional="true">
+        <name>android.frameworks.stats</name>
+        <version>1.0</version>
+        <interface>
+            <name>IStats</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <!-- TODO(b/171424919) set to required once trusty installs it. -->
+    <hal format="hidl" optional="true">
+        <name>android.hardware.media.c2</name>
+        <version>1.1</version>
+        <interface>
+            <name>IComponentStore</name>
+            <instance>software</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.hidl.allocator</name>
+        <version>1.0</version>
+        <interface>
+            <name>IAllocator</name>
+            <instance>ashmem</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.hidl.manager</name>
+        <version>1.2</version>
+        <interface>
+            <name>IServiceManager</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.hidl.memory</name>
+        <version>1.0</version>
+        <interface>
+            <name>IMapper</name>
+            <instance>ashmem</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.hidl.token</name>
+        <version>1.0</version>
+        <interface>
+            <name>ITokenManager</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.system.net.netd</name>
+        <version>1.1</version>
+        <interface>
+            <name>INetd</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <!-- TODO(b/171424919) set to required once trusty installs it. -->
+    <hal format="hidl" optional="true">
+        <name>android.system.suspend</name>
+        <version>1.0</version>
+        <interface>
+            <name>ISystemSuspend</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+    <hal format="hidl" optional="false">
+        <name>android.system.wifi.keystore</name>
+        <version>1.0</version>
+        <interface>
+            <name>IKeystore</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+</compatibility-matrix>