diff --git a/adb/daemon/remount_service.cpp b/adb/daemon/remount_service.cpp
index 7999ddc..ce494ee 100644
--- a/adb/daemon/remount_service.cpp
+++ b/adb/daemon/remount_service.cpp
@@ -27,68 +27,62 @@
 #include "adb_io.h"
 #include "adb_unique_fd.h"
 
-void remount_service(unique_fd fd, const std::string& cmd) {
-    static constexpr char remount_cmd[] = "/system/bin/remount";
-    static constexpr char remount_failed[] = "remount failed\n";
+static constexpr char kRemountCmd[] = "/system/bin/remount";
 
+static bool do_remount(int fd, const std::string& cmd) {
     if (getuid() != 0) {
-        WriteFdExactly(fd.get(), "Not running as root. Try \"adb root\" first.\n");
-        WriteFdExactly(fd.get(), remount_failed);
-        return;
+        WriteFdExactly(fd, "Not running as root. Try \"adb root\" first.\n");
+        return false;
     }
 
-    auto pid = vfork();
+    auto pid = fork();
     if (pid < 0) {
-        WriteFdFmt(fd.get(), "Failed to fork to %s: %s\n", remount_cmd, strerror(errno));
-        WriteFdExactly(fd.get(), remount_failed);
-        return;
+        WriteFdFmt(fd, "Failed to fork to %s: %s\n", kRemountCmd, strerror(errno));
+        return false;
     }
 
     if (pid == 0) {
         // child side of the fork
-        fcntl(fd.get(), F_SETFD, 0);
-        dup2(fd.get(), STDIN_FILENO);
-        dup2(fd.get(), STDOUT_FILENO);
-        dup2(fd.get(), STDERR_FILENO);
+        dup2(fd, STDIN_FILENO);
+        dup2(fd, STDOUT_FILENO);
+        dup2(fd, STDERR_FILENO);
 
-        execl(remount_cmd, remount_cmd, cmd.empty() ? nullptr : cmd.c_str(), nullptr);
-        _exit(-errno ?: 42);
+        execl(kRemountCmd, kRemountCmd, cmd.empty() ? nullptr : cmd.c_str(), nullptr);
+        _exit(errno);
     }
 
     int wstatus = 0;
     auto ret = waitpid(pid, &wstatus, 0);
 
     if (ret == -1) {
-        WriteFdFmt(fd.get(), "Failed to wait for %s: %s\n", remount_cmd, strerror(errno));
-        goto err;
-    }
-
-    if (ret != pid) {
-        WriteFdFmt(fd.get(), "pid %d and waitpid return %d do not match for %s\n",
-                   static_cast<int>(pid), static_cast<int>(ret), remount_cmd);
-        goto err;
+        WriteFdFmt(fd, "Failed to wait for %s: %s\n", kRemountCmd, strerror(errno));
+        return false;
+    } else if (ret != pid) {
+        WriteFdFmt(fd, "pid %d and waitpid return %d do not match for %s\n",
+                   static_cast<int>(pid), static_cast<int>(ret), kRemountCmd);
+        return false;
     }
 
     if (WIFSIGNALED(wstatus)) {
-        WriteFdFmt(fd.get(), "%s terminated with signal %s\n", remount_cmd,
+        WriteFdFmt(fd, "%s terminated with signal %s\n", kRemountCmd,
                    strsignal(WTERMSIG(wstatus)));
-        goto err;
+        return false;
     }
 
     if (!WIFEXITED(wstatus)) {
-        WriteFdFmt(fd.get(), "%s stopped with status 0x%x\n", remount_cmd, wstatus);
-        goto err;
+        WriteFdFmt(fd, "%s stopped with status 0x%x\n", kRemountCmd, wstatus);
+        return false;
     }
 
     if (WEXITSTATUS(wstatus)) {
-        WriteFdFmt(fd.get(), "%s exited with status %d\n", remount_cmd,
-                   static_cast<signed char>(WEXITSTATUS(wstatus)));
-        goto err;
+        WriteFdFmt(fd, "%s exited with status %d\n", kRemountCmd, WEXITSTATUS(wstatus));
+        return false;
     }
 
-    WriteFdExactly(fd.get(), "remount succeeded\n");
-    return;
+    return true;
+}
 
-err:
-    WriteFdExactly(fd.get(), remount_failed);
+void remount_service(unique_fd fd, const std::string& cmd) {
+    const char* success = do_remount(fd.get(), cmd) ? "succeeded" : "failed";
+    WriteFdFmt(fd.get(), "remount %s\n", success);
 }
diff --git a/adb/daemon/set_verity_enable_state_service.cpp b/adb/daemon/set_verity_enable_state_service.cpp
index 658261e..889229f 100644
--- a/adb/daemon/set_verity_enable_state_service.cpp
+++ b/adb/daemon/set_verity_enable_state_service.cpp
@@ -52,14 +52,13 @@
 }
 
 static bool make_block_device_writable(const std::string& dev) {
-    int fd = unix_open(dev, O_RDONLY | O_CLOEXEC);
+    unique_fd fd(unix_open(dev, O_RDONLY | O_CLOEXEC));
     if (fd == -1) {
         return false;
     }
 
     int OFF = 0;
     bool result = (ioctl(fd, BLKROSET, &OFF) != -1);
-    unix_close(fd);
     return result;
 }
 
diff --git a/adb/daemon/usb.cpp b/adb/daemon/usb.cpp
index 598f2cd..a44ff43 100644
--- a/adb/daemon/usb.cpp
+++ b/adb/daemon/usb.cpp
@@ -654,9 +654,10 @@
 }
 
 void usb_init() {
-    if (!android::base::GetBoolProperty("persist.adb.nonblocking_ffs", false)) {
-        usb_init_legacy();
-    } else {
+    bool use_nonblocking = android::base::GetBoolProperty("persist.adb.nonblocking_ffs", true);
+    if (use_nonblocking) {
         std::thread(usb_ffs_open_thread).detach();
+    } else {
+        usb_init_legacy();
     }
 }
diff --git a/fs_mgr/fs_mgr_remount.cpp b/fs_mgr/fs_mgr_remount.cpp
index 6312734..5c4008c 100644
--- a/fs_mgr/fs_mgr_remount.cpp
+++ b/fs_mgr/fs_mgr_remount.cpp
@@ -263,35 +263,43 @@
 
     // Check verity and optionally setup overlayfs backing.
     auto reboot_later = false;
+    auto uses_overlayfs = fs_mgr_overlayfs_valid() != OverlayfsValidResult::kNotSupported;
     for (auto it = partitions.begin(); it != partitions.end();) {
         auto& entry = *it;
         auto& mount_point = entry.mount_point;
         if (fs_mgr_is_verity_enabled(entry)) {
-            LOG(WARNING) << "Verity enabled on " << mount_point;
-            if (can_reboot &&
-                (android::base::GetProperty("ro.boot.vbmeta.devices_state", "") != "locked")) {
+            retval = VERITY_PARTITION;
+            if (android::base::GetProperty("ro.boot.vbmeta.devices_state", "") != "locked") {
                 if (AvbOps* ops = avb_ops_user_new()) {
                     auto ret = avb_user_verity_set(
                             ops, android::base::GetProperty("ro.boot.slot_suffix", "").c_str(),
                             false);
                     avb_ops_user_free(ops);
                     if (ret) {
-                        if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) {
-                            retval = VERITY_PARTITION;
+                        LOG(WARNING) << "Disable verity for " << mount_point;
+                        reboot_later = can_reboot;
+                        if (reboot_later) {
                             // w/o overlayfs available, also check for dedupe
-                            reboot_later = true;
-                            ++it;
-                            continue;
+                            if (!uses_overlayfs) {
+                                ++it;
+                                continue;
+                            }
+                            reboot(false);
                         }
-                        reboot(false);
                     } else if (fs_mgr_set_blk_ro(entry.blk_device, false)) {
                         fec::io fh(entry.blk_device.c_str(), O_RDWR);
-                        if (fh && fh.set_verity_status(false)) reboot_later = true;
+                        if (fh && fh.set_verity_status(false)) {
+                            LOG(WARNING) << "Disable verity for " << mount_point;
+                            reboot_later = can_reboot;
+                            if (reboot_later && !uses_overlayfs) {
+                                ++it;
+                                continue;
+                            }
+                        }
                     }
                 }
             }
             LOG(ERROR) << "Skipping " << mount_point;
-            retval = VERITY_PARTITION;
             it = partitions.erase(it);
             continue;
         }
@@ -318,7 +326,8 @@
     }
 
     // Mount overlayfs.
-    if (!fs_mgr_overlayfs_mount_all(&partitions)) {
+    errno = 0;
+    if (!fs_mgr_overlayfs_mount_all(&partitions) && errno) {
         retval = BAD_OVERLAY;
         PLOG(ERROR) << "Can not mount overlayfs for partitions";
     }
@@ -346,11 +355,15 @@
                 break;
             }
             if ((mount_point == "/") && (rentry.mount_point == "/system")) {
-                if (blk_device != "/dev/root") blk_device = rentry.blk_device;
+                blk_device = rentry.blk_device;
                 mount_point = "/system";
                 break;
             }
         }
+        if (blk_device == "/dev/root") {
+            auto from_fstab = GetEntryForMountPoint(&fstab, mount_point);
+            if (from_fstab) blk_device = from_fstab->blk_device;
+        }
         fs_mgr_set_blk_ro(blk_device, false);
 
         // Now remount!
diff --git a/fs_mgr/libfiemap_writer/fiemap_writer.cpp b/fs_mgr/libfiemap_writer/fiemap_writer.cpp
index 3d41876..99a1a2f 100644
--- a/fs_mgr/libfiemap_writer/fiemap_writer.cpp
+++ b/fs_mgr/libfiemap_writer/fiemap_writer.cpp
@@ -618,7 +618,6 @@
 
     fmap->file_path_ = abs_path;
     fmap->bdev_path_ = bdev_path;
-    fmap->file_fd_ = std::move(file_fd);
     fmap->file_size_ = file_size;
     fmap->bdev_size_ = bdevsz;
     fmap->fs_type_ = fs_type;
diff --git a/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp b/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
index ab4efae..66eb9ae 100644
--- a/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
+++ b/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
@@ -38,6 +38,9 @@
 
 #include "utility.h"
 
+namespace android {
+namespace fiemap_writer {
+
 using namespace std;
 using namespace std::string_literals;
 using namespace android::fiemap_writer;
@@ -234,6 +237,105 @@
     ASSERT_EQ(errno, ENOENT);
 }
 
+static string ReadSplitFiles(const std::string& base_path, size_t num_files) {
+    std::string result;
+    for (int i = 0; i < num_files; i++) {
+        std::string path = base_path + android::base::StringPrintf(".%04d", i);
+        std::string data;
+        if (!android::base::ReadFileToString(path, &data)) {
+            return {};
+        }
+        result += data;
+    }
+    return result;
+}
+
+TEST_F(SplitFiemapTest, WriteWholeFile) {
+    static constexpr size_t kChunkSize = 32768;
+    static constexpr size_t kSize = kChunkSize * 3;
+    auto ptr = SplitFiemap::Create(testfile, kSize, kChunkSize);
+    ASSERT_NE(ptr, nullptr);
+
+    auto buffer = std::make_unique<int[]>(kSize / sizeof(int));
+    for (size_t i = 0; i < kSize / sizeof(int); i++) {
+        buffer[i] = i;
+    }
+    ASSERT_TRUE(ptr->Write(buffer.get(), kSize));
+
+    std::string expected(reinterpret_cast<char*>(buffer.get()), kSize);
+    auto actual = ReadSplitFiles(testfile, 3);
+    ASSERT_EQ(expected.size(), actual.size());
+    EXPECT_EQ(memcmp(expected.data(), actual.data(), actual.size()), 0);
+}
+
+TEST_F(SplitFiemapTest, WriteFileInChunks1) {
+    static constexpr size_t kChunkSize = 32768;
+    static constexpr size_t kSize = kChunkSize * 3;
+    auto ptr = SplitFiemap::Create(testfile, kSize, kChunkSize);
+    ASSERT_NE(ptr, nullptr);
+
+    auto buffer = std::make_unique<int[]>(kSize / sizeof(int));
+    for (size_t i = 0; i < kSize / sizeof(int); i++) {
+        buffer[i] = i;
+    }
+
+    // Write in chunks of 1000 (so some writes straddle the boundary of two
+    // files).
+    size_t bytes_written = 0;
+    while (bytes_written < kSize) {
+        size_t to_write = std::min(kSize - bytes_written, (size_t)1000);
+        char* data = reinterpret_cast<char*>(buffer.get()) + bytes_written;
+        ASSERT_TRUE(ptr->Write(data, to_write));
+        bytes_written += to_write;
+    }
+
+    std::string expected(reinterpret_cast<char*>(buffer.get()), kSize);
+    auto actual = ReadSplitFiles(testfile, 3);
+    ASSERT_EQ(expected.size(), actual.size());
+    EXPECT_EQ(memcmp(expected.data(), actual.data(), actual.size()), 0);
+}
+
+TEST_F(SplitFiemapTest, WriteFileInChunks2) {
+    static constexpr size_t kChunkSize = 32768;
+    static constexpr size_t kSize = kChunkSize * 3;
+    auto ptr = SplitFiemap::Create(testfile, kSize, kChunkSize);
+    ASSERT_NE(ptr, nullptr);
+
+    auto buffer = std::make_unique<int[]>(kSize / sizeof(int));
+    for (size_t i = 0; i < kSize / sizeof(int); i++) {
+        buffer[i] = i;
+    }
+
+    // Write in chunks of 32KiB so every write is exactly at the end of the
+    // current file.
+    size_t bytes_written = 0;
+    while (bytes_written < kSize) {
+        size_t to_write = std::min(kSize - bytes_written, kChunkSize);
+        char* data = reinterpret_cast<char*>(buffer.get()) + bytes_written;
+        ASSERT_TRUE(ptr->Write(data, to_write));
+        bytes_written += to_write;
+    }
+
+    std::string expected(reinterpret_cast<char*>(buffer.get()), kSize);
+    auto actual = ReadSplitFiles(testfile, 3);
+    ASSERT_EQ(expected.size(), actual.size());
+    EXPECT_EQ(memcmp(expected.data(), actual.data(), actual.size()), 0);
+}
+
+TEST_F(SplitFiemapTest, WritePastEnd) {
+    static constexpr size_t kChunkSize = 32768;
+    static constexpr size_t kSize = kChunkSize * 3;
+    auto ptr = SplitFiemap::Create(testfile, kSize, kChunkSize);
+    ASSERT_NE(ptr, nullptr);
+
+    auto buffer = std::make_unique<int[]>(kSize / sizeof(int));
+    for (size_t i = 0; i < kSize / sizeof(int); i++) {
+        buffer[i] = i;
+    }
+    ASSERT_TRUE(ptr->Write(buffer.get(), kSize));
+    ASSERT_FALSE(ptr->Write(buffer.get(), kSize));
+}
+
 class VerifyBlockWritesExt4 : public ::testing::Test {
     // 2GB Filesystem and 4k block size by default
     static constexpr uint64_t block_size = 4096;
@@ -333,6 +435,11 @@
     return true;
 }
 
+}  // namespace fiemap_writer
+}  // namespace android
+
+using namespace android::fiemap_writer;
+
 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);
     if (argc <= 1) {
diff --git a/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h b/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h
index 831bc75..9486122 100644
--- a/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h
+++ b/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h
@@ -88,9 +88,6 @@
     // Block device on which we have created the file.
     std::string bdev_path_;
 
-    // File descriptors for the file and block device
-    ::android::base::unique_fd file_fd_;
-
     // Size in bytes of the file this class is writing
     uint64_t file_size_;
 
diff --git a/fs_mgr/libfiemap_writer/include/libfiemap_writer/split_fiemap_writer.h b/fs_mgr/libfiemap_writer/include/libfiemap_writer/split_fiemap_writer.h
index 765cc84..07f3c10 100644
--- a/fs_mgr/libfiemap_writer/include/libfiemap_writer/split_fiemap_writer.h
+++ b/fs_mgr/libfiemap_writer/include/libfiemap_writer/split_fiemap_writer.h
@@ -23,6 +23,8 @@
 #include <string>
 #include <vector>
 
+#include <android-base/unique_fd.h>
+
 #include "fiemap_writer.h"
 
 namespace android {
@@ -54,6 +56,16 @@
     // this returns true and does not report an error.
     static bool RemoveSplitFiles(const std::string& file_path, std::string* message = nullptr);
 
+    // Return whether all components of a split file still have pinned extents.
+    bool HasPinnedExtents() const;
+
+    // Helper method for writing data that spans files. Note there is no seek
+    // method (yet); this starts at 0 and increments the position by |bytes|.
+    bool Write(const void* data, uint64_t bytes);
+
+    // Flush all writes to all split files.
+    bool Flush();
+
     const std::vector<struct fiemap_extent>& extents();
     uint32_t block_size() const;
     uint64_t size() const { return total_size_; }
@@ -73,6 +85,11 @@
     std::vector<FiemapUniquePtr> files_;
     std::vector<struct fiemap_extent> extents_;
     uint64_t total_size_ = 0;
+
+    // Most recently open file and position for Write().
+    size_t cursor_index_ = 0;
+    uint64_t cursor_file_pos_ = 0;
+    android::base::unique_fd cursor_fd_;
 };
 
 }  // namespace fiemap_writer
diff --git a/fs_mgr/libfiemap_writer/split_fiemap_writer.cpp b/fs_mgr/libfiemap_writer/split_fiemap_writer.cpp
index 1f80370..dbb67a8 100644
--- a/fs_mgr/libfiemap_writer/split_fiemap_writer.cpp
+++ b/fs_mgr/libfiemap_writer/split_fiemap_writer.cpp
@@ -176,6 +176,15 @@
     return ok;
 }
 
+bool SplitFiemap::HasPinnedExtents() const {
+    for (const auto& file : files_) {
+        if (!FiemapWriter::HasPinnedExtents(file->file_path())) {
+            return false;
+        }
+    }
+    return true;
+}
+
 const std::vector<struct fiemap_extent>& SplitFiemap::extents() {
     if (extents_.empty()) {
         for (const auto& file : files_) {
@@ -186,6 +195,76 @@
     return extents_;
 }
 
+bool SplitFiemap::Write(const void* data, uint64_t bytes) {
+    // Open the current file.
+    FiemapWriter* file = files_[cursor_index_].get();
+
+    const uint8_t* data_ptr = reinterpret_cast<const uint8_t*>(data);
+    uint64_t bytes_remaining = bytes;
+    while (bytes_remaining) {
+        // How many bytes can we write into the current file?
+        uint64_t file_bytes_left = file->size() - cursor_file_pos_;
+        if (!file_bytes_left) {
+            if (cursor_index_ == files_.size() - 1) {
+                LOG(ERROR) << "write past end of file requested";
+                return false;
+            }
+
+            // No space left in the current file, but we have more files to
+            // use, so prep the next one.
+            cursor_fd_ = {};
+            cursor_file_pos_ = 0;
+            file = files_[++cursor_index_].get();
+            file_bytes_left = file->size();
+        }
+
+        // Open the current file if it's not open.
+        if (cursor_fd_ < 0) {
+            cursor_fd_.reset(open(file->file_path().c_str(), O_CLOEXEC | O_WRONLY));
+            if (cursor_fd_ < 0) {
+                PLOG(ERROR) << "open failed: " << file->file_path();
+                return false;
+            }
+            CHECK(cursor_file_pos_ == 0);
+        }
+
+        if (!FiemapWriter::HasPinnedExtents(file->file_path())) {
+            LOG(ERROR) << "file is no longer pinned: " << file->file_path();
+            return false;
+        }
+
+        uint64_t bytes_to_write = std::min(file_bytes_left, bytes_remaining);
+        if (!android::base::WriteFully(cursor_fd_, data_ptr, bytes_to_write)) {
+            PLOG(ERROR) << "write failed: " << file->file_path();
+            return false;
+        }
+        data_ptr += bytes_to_write;
+        bytes_remaining -= bytes_to_write;
+        cursor_file_pos_ += bytes_to_write;
+    }
+
+    // If we've reached the end of the current file, close it for sanity.
+    if (cursor_file_pos_ == file->size()) {
+        cursor_fd_ = {};
+    }
+    return true;
+}
+
+bool SplitFiemap::Flush() {
+    for (const auto& file : files_) {
+        unique_fd fd(open(file->file_path().c_str(), O_RDONLY | O_CLOEXEC));
+        if (fd < 0) {
+            PLOG(ERROR) << "open failed: " << file->file_path();
+            return false;
+        }
+        if (fsync(fd)) {
+            PLOG(ERROR) << "fsync failed: " << file->file_path();
+            return false;
+        }
+    }
+    return true;
+}
+
 SplitFiemap::~SplitFiemap() {
     if (!creating_) {
         return;
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index a6baf1d..bd5a4fe 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -48,6 +48,7 @@
 TMPDIR=${TMPDIR:-/tmp}
 print_time=false
 start_time=`date +%s`
+ACTIVE_SLOT=
 
 ##
 ##  Helper Functions
@@ -77,6 +78,7 @@
       wc -l | grep '^1$' >/dev/null
     fi
 }
+
 [ "USAGE: inRecovery
 
 Returns: true if device is in recovery mode" ]
@@ -221,15 +223,23 @@
 
 Returns: waits until the device has returned for adb or optional timeout" ]
 adb_wait() {
+  local ret
   if [ -n "${1}" ]; then
     echo -n ". . . waiting `format_duration ${1}`" ${ANDROID_SERIAL} ${USB_ADDRESS} "${CR}"
     timeout --preserve-status --signal=KILL ${1} adb wait-for-device 2>/dev/null
-    local ret=${?}
+    ret=${?}
     echo -n "                                                                             ${CR}"
-    return ${ret}
   else
     adb wait-for-device
+    ret=${?}
   fi
+  if [ 0 = ${ret} -a -n "${ACTIVE_SLOT}" ]; then
+    local active_slot=`get_active_slot`
+    if [ X"${ACTIVE_SLOT}" != X"${active_slot}" ]; then
+      echo "${ORANGE}[  WARNING ]${NORMAL} Active slot changed from ${ACTIVE_SLOT} to ${active_slot}" >&2
+    fi
+  fi
+  return ${ret}
 }
 
 [ "USAGE: usb_status > stdout
@@ -254,33 +264,50 @@
 
 Returns: waits until the device has returned for fastboot or optional timeout" ]
 fastboot_wait() {
+  local ret
   # fastboot has no wait-for-device, but it does an automatic
   # wait and requires (even a nonsensical) command to do so.
   if [ -n "${1}" ]; then
     echo -n ". . . waiting `format_duration ${1}`" ${ANDROID_SERIAL} ${USB_ADDRESS} "${CR}"
     timeout --preserve-status --signal=KILL ${1} fastboot wait-for-device >/dev/null 2>/dev/null
-    local ret=${?}
+    ret=${?}
     echo -n "                                                                             ${CR}"
     ( exit ${ret} )
   else
     fastboot wait-for-device >/dev/null 2>/dev/null
   fi ||
     inFastboot
+  ret=${?}
+  if [ 0 = ${ret} -a -n "${ACTIVE_SLOT}" ]; then
+    local active_slot=`get_active_slot`
+    if [ X"${ACTIVE_SLOT}" != X"${active_slot}" ]; then
+      echo "${ORANGE}[  WARNING ]${NORMAL} Active slot changed from ${ACTIVE_SLOT} to ${active_slot}" >&2
+    fi
+  fi
+  return ${ret}
 }
 
 [ "USAGE: recovery_wait [timeout]
 
 Returns: waits until the device has returned for recovery or optional timeout" ]
 recovery_wait() {
+  local ret
   if [ -n "${1}" ]; then
     echo -n ". . . waiting `format_duration ${1}`" ${ANDROID_SERIAL} ${USB_ADDRESS} "${CR}"
     timeout --preserve-status --signal=KILL ${1} adb wait-for-recovery 2>/dev/null
-    local ret=${?}
+    ret=${?}
     echo -n "                                                                             ${CR}"
-    return ${ret}
   else
     adb wait-for-recovery
+    ret=${?}
   fi
+  if [ 0 = ${ret} -a -n "${ACTIVE_SLOT}" ]; then
+    local active_slot=`get_active_slot`
+    if [ X"${ACTIVE_SLOT}" != X"${active_slot}" ]; then
+      echo "${ORANGE}[  WARNING ]${NORMAL} Active slot changed from ${ACTIVE_SLOT} to ${active_slot}" >&2
+    fi
+  fi
+  return ${ret}
 }
 
 [ "any_wait [timeout]
@@ -326,7 +353,7 @@
     [ root != "`adb_sh echo '${USER}' </dev/null`" ]
 }
 
-[ "USAGE: fastboot_getvar var expected
+[ "USAGE: fastboot_getvar var expected >/dev/stderr
 
 Returns: true if var output matches expected" ]
 fastboot_getvar() {
@@ -350,6 +377,19 @@
   echo ${O} >&2
 }
 
+[ "USAGE: get_active_slot >/dev/stdout
+
+Returns: with a or b string reporting active slot" ]
+get_active_slot() {
+  if inAdb || inRecovery; then
+    get_property ro.boot.slot_suffix | tr -d _
+  elif inFastboot; then
+    fastboot_getvar current-slot 2>&1 | sed -n 's/current-slot: //p'
+  else
+    false
+  fi
+}
+
 [ "USAGE: restore
 
 Do nothing: should be redefined when necessary.  Called after cleanup.
@@ -583,6 +623,9 @@
 BUILD_DESCRIPTION=`get_property ro.build.description`
 [ -z "${BUILD_DESCRIPTION}" ] ||
   echo "${BLUE}[     INFO ]${NORMAL} ${BUILD_DESCRIPTION}" >&2
+ACTIVE_SLOT=`get_active_slot`
+[ -z "${ACTIVE_SLOT}" ] ||
+  echo "${BLUE}[     INFO ]${NORMAL} active slot is ${ACTIVE_SLOT}" >&2
 
 # Report existing partition sizes
 adb_sh ls -l /dev/block/by-name/ </dev/null 2>/dev/null |
@@ -1031,13 +1074,7 @@
   check_eq "${A}" "${B}" system after flash vendor
   adb_root ||
     die "adb root"
-  B="`adb_cat /vendor/hello`" &&
-    if ${is_userspace_fastboot} || ! ${overlayfs_needed}; then
-      die "re-read /vendor/hello after flash vendor"
-    else
-      echo "${ORANGE}[  WARNING ]${NORMAL} user fastboot missing required to invalidate, ignoring a failure" >&2
-      echo "${ORANGE}[  WARNING ]${NORMAL} re-read /vendor/hello after flash vendor" >&2
-    fi
+  B="`adb_cat /vendor/hello`"
   if ${is_userspace_fastboot} || ! ${overlayfs_needed}; then
     check_eq "cat: /vendor/hello: No such file or directory" "${B}" \
              vendor content after flash vendor
diff --git a/init/Android.mk b/init/Android.mk
index ac05542..cc514ed 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -63,8 +63,9 @@
 LOCAL_UNSTRIPPED_PATH := $(TARGET_RAMDISK_OUT_UNSTRIPPED)
 
 # Set up the same mount points on the ramdisk that system-as-root contains.
-LOCAL_POST_INSTALL_CMD := \
-    mkdir -p $(TARGET_RAMDISK_OUT)/dev \
+LOCAL_POST_INSTALL_CMD := mkdir -p \
+    $(TARGET_RAMDISK_OUT)/apex \
+    $(TARGET_RAMDISK_OUT)/dev \
     $(TARGET_RAMDISK_OUT)/mnt \
     $(TARGET_RAMDISK_OUT)/proc \
     $(TARGET_RAMDISK_OUT)/sys \
diff --git a/mkbootimg/unpack_bootimg.py b/mkbootimg/unpack_bootimg.py
index 6b5d5d0..789bf5e 100755
--- a/mkbootimg/unpack_bootimg.py
+++ b/mkbootimg/unpack_bootimg.py
@@ -48,12 +48,12 @@
     print('boot_magic: %s' % boot_magic)
     kernel_ramdisk_second_info = unpack('10I', args.boot_img.read(10 * 4))
     print('kernel_size: %s' % kernel_ramdisk_second_info[0])
-    print('kernel load address: %s' % kernel_ramdisk_second_info[1])
+    print('kernel load address: %#x' % kernel_ramdisk_second_info[1])
     print('ramdisk size: %s' % kernel_ramdisk_second_info[2])
-    print('ramdisk load address: %s' % kernel_ramdisk_second_info[3])
+    print('ramdisk load address: %#x' % kernel_ramdisk_second_info[3])
     print('second bootloader size: %s' % kernel_ramdisk_second_info[4])
-    print('second bootloader load address: %s' % kernel_ramdisk_second_info[5])
-    print('kernel tags load address: %s' % kernel_ramdisk_second_info[6])
+    print('second bootloader load address: %#x' % kernel_ramdisk_second_info[5])
+    print('kernel tags load address: %#x' % kernel_ramdisk_second_info[6])
     print('page size: %s' % kernel_ramdisk_second_info[7])
     print('boot image header version: %s' % kernel_ramdisk_second_info[8])
     print('os version and patch level: %s' % kernel_ramdisk_second_info[9])
@@ -77,7 +77,7 @@
         recovery_dtbo_size = unpack('I', args.boot_img.read(1 * 4))[0]
         print('recovery dtbo size: %s' % recovery_dtbo_size)
         recovery_dtbo_offset = unpack('Q', args.boot_img.read(8))[0]
-        print('recovery dtbo offset: %s' % recovery_dtbo_offset)
+        print('recovery dtbo offset: %#x' % recovery_dtbo_offset)
         boot_header_size = unpack('I', args.boot_img.read(4))[0]
         print('boot header size: %s' % boot_header_size)
     else:
@@ -86,7 +86,7 @@
         dtb_size = unpack('I', args.boot_img.read(4))[0]
         print('dtb size: %s' % dtb_size)
         dtb_load_address = unpack('Q', args.boot_img.read(8))[0]
-        print('dtb address: %s' % dtb_load_address)
+        print('dtb address: %#x' % dtb_load_address)
     else:
         dtb_size = 0
 
@@ -103,10 +103,11 @@
                                  ) # header + kernel
     image_info_list.append((ramdisk_offset, ramdisk_size, 'ramdisk'))
 
-    second_offset = page_size * (
-        num_header_pages + num_kernel_pages + num_ramdisk_pages
-    )  # header + kernel + ramdisk
-    image_info_list.append((second_offset, second_size, 'second'))
+    if second_size > 0:
+        second_offset = page_size * (
+                num_header_pages + num_kernel_pages + num_ramdisk_pages
+                )  # header + kernel + ramdisk
+        image_info_list.append((second_offset, second_size, 'second'))
 
     if recovery_dtbo_size > 0:
         image_info_list.append((recovery_dtbo_offset, recovery_dtbo_size,
diff --git a/rootdir/etc/ld.config.legacy.txt b/rootdir/etc/ld.config.legacy.txt
index 5a9a5e3..d4d5c28 100644
--- a/rootdir/etc/ld.config.legacy.txt
+++ b/rootdir/etc/ld.config.legacy.txt
@@ -94,11 +94,7 @@
 namespace.media.permitted.paths = /apex/com.android.media/${LIB}/extractors
 
 namespace.media.links = default
-namespace.media.link.default.shared_libs  = %LLNDK_LIBRARIES%
-namespace.media.link.default.shared_libs += libandroid.so
-namespace.media.link.default.shared_libs += libbinder_ndk.so
-namespace.media.link.default.shared_libs += libmediametrics.so
-namespace.media.link.default.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
+namespace.media.link.default.allow_all_shared_libs = true
 
 ###############################################################################
 # "conscrypt" APEX namespace
diff --git a/rootdir/init.rc b/rootdir/init.rc
index b44cc3e..f2e7a7c 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -387,6 +387,7 @@
     restorecon_recursive /metadata
     mkdir /metadata/vold
     chmod 0700 /metadata/vold
+    mkdir /metadata/password_slots 0771 root system
 
 on late-fs
     # Ensure that tracefs has the correct permissions.
diff --git a/rootdir/init.zygote32.rc b/rootdir/init.zygote32.rc
index e8c5d8e..f8e680d 100644
--- a/rootdir/init.zygote32.rc
+++ b/rootdir/init.zygote32.rc
@@ -5,7 +5,6 @@
     group root readproc reserved_disk
     socket zygote stream 660 root system
     socket blastula_pool stream 660 root system
-    updatable
     onrestart write /sys/android_power/request_state wake
     onrestart write /sys/power/state on
     onrestart restart audioserver
diff --git a/rootdir/init.zygote32_64.rc b/rootdir/init.zygote32_64.rc
index 9c7e807..0235370 100644
--- a/rootdir/init.zygote32_64.rc
+++ b/rootdir/init.zygote32_64.rc
@@ -5,7 +5,6 @@
     group root readproc reserved_disk
     socket zygote stream 660 root system
     socket blastula_pool stream 660 root system
-    updatable
     onrestart write /sys/android_power/request_state wake
     onrestart write /sys/power/state on
     onrestart restart audioserver
@@ -22,6 +21,5 @@
     group root readproc reserved_disk
     socket zygote_secondary stream 660 root system
     socket blastula_pool_secondary stream 660 root system
-    updatable
     onrestart restart zygote
     writepid /dev/cpuset/foreground/tasks
diff --git a/rootdir/init.zygote64.rc b/rootdir/init.zygote64.rc
index 9908c99..3f3cc15 100644
--- a/rootdir/init.zygote64.rc
+++ b/rootdir/init.zygote64.rc
@@ -5,7 +5,6 @@
     group root readproc reserved_disk
     socket zygote stream 660 root system
     socket blastula_pool stream 660 root system
-    updatable
     onrestart write /sys/android_power/request_state wake
     onrestart write /sys/power/state on
     onrestart restart audioserver
diff --git a/rootdir/init.zygote64_32.rc b/rootdir/init.zygote64_32.rc
index 0b5edff..fae38c9 100644
--- a/rootdir/init.zygote64_32.rc
+++ b/rootdir/init.zygote64_32.rc
@@ -5,7 +5,6 @@
     group root readproc reserved_disk
     socket zygote stream 660 root system
     socket blastula_pool stream 660 root system
-    updatable
     onrestart write /sys/android_power/request_state wake
     onrestart write /sys/power/state on
     onrestart restart audioserver
@@ -22,6 +21,5 @@
     group root readproc reserved_disk
     socket zygote_secondary stream 660 root system
     socket blastula_pool_secondary stream 660 root system
-    updatable
     onrestart restart zygote
     writepid /dev/cpuset/foreground/tasks
diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp
index e1de130..2b35819 100644
--- a/sdcard/sdcard.cpp
+++ b/sdcard/sdcard.cpp
@@ -27,6 +27,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <vector>
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
@@ -99,14 +100,21 @@
 
 static bool sdcardfs_setup(const std::string& source_path, const std::string& dest_path,
                            uid_t fsuid, gid_t fsgid, bool multi_user, userid_t userid, gid_t gid,
-                           mode_t mask, bool derive_gid, bool default_normal, bool use_esdfs) {
+                           mode_t mask, bool derive_gid, bool default_normal, bool unshared_obb,
+                           bool use_esdfs) {
+    // Add new options at the end of the vector.
+    std::vector<std::string> new_opts_list;
+    if (multi_user) new_opts_list.push_back("multiuser,");
+    if (derive_gid) new_opts_list.push_back("derive_gid,");
+    if (default_normal) new_opts_list.push_back("default_normal,");
+    if (unshared_obb) new_opts_list.push_back("unshared_obb,");
     // Try several attempts, each time with one less option, to gracefully
     // handle older kernels that aren't updated yet.
-    for (int i = 0; i < 4; i++) {
+    for (int i = 0; i <= new_opts_list.size(); ++i) {
         std::string new_opts;
-        if (multi_user && i < 3) new_opts += "multiuser,";
-        if (derive_gid && i < 2) new_opts += "derive_gid,";
-        if (default_normal && i < 1) new_opts += "default_normal,";
+        for (int j = 0; j < new_opts_list.size() - i; ++j) {
+            new_opts += new_opts_list[j];
+        }
 
         auto opts = android::base::StringPrintf("fsuid=%d,fsgid=%d,%smask=%d,userid=%d,gid=%d",
                                                 fsuid, fsgid, new_opts.c_str(), mask, userid, gid);
@@ -142,13 +150,14 @@
     return true;
 }
 
-static bool sdcardfs_setup_secondary(const std::string& default_path, const std::string& source_path,
-                                     const std::string& dest_path, uid_t fsuid, gid_t fsgid,
-                                     bool multi_user, userid_t userid, gid_t gid, mode_t mask,
-                                     bool derive_gid, bool default_normal, bool use_esdfs) {
+static bool sdcardfs_setup_secondary(const std::string& default_path,
+                                     const std::string& source_path, const std::string& dest_path,
+                                     uid_t fsuid, gid_t fsgid, bool multi_user, userid_t userid,
+                                     gid_t gid, mode_t mask, bool derive_gid, bool default_normal,
+                                     bool unshared_obb, bool use_esdfs) {
     if (use_esdfs) {
         return sdcardfs_setup(source_path, dest_path, fsuid, fsgid, multi_user, userid, gid, mask,
-                              derive_gid, default_normal, use_esdfs);
+                              derive_gid, default_normal, unshared_obb, use_esdfs);
     } else {
         return sdcardfs_setup_bind_remount(default_path, dest_path, gid, mask);
     }
@@ -156,7 +165,7 @@
 
 static void run_sdcardfs(const std::string& source_path, const std::string& label, uid_t uid,
                          gid_t gid, userid_t userid, bool multi_user, bool full_write,
-                         bool derive_gid, bool default_normal, bool use_esdfs) {
+                         bool derive_gid, bool default_normal, bool unshared_obb, bool use_esdfs) {
     std::string dest_path_default = "/mnt/runtime/default/" + label;
     std::string dest_path_read = "/mnt/runtime/read/" + label;
     std::string dest_path_write = "/mnt/runtime/write/" + label;
@@ -167,16 +176,17 @@
         // Multi-user storage is fully isolated per user, so "other"
         // permissions are completely masked off.
         if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
-                            AID_SDCARD_RW, 0006, derive_gid, default_normal, use_esdfs) ||
+                            AID_SDCARD_RW, 0006, derive_gid, default_normal, unshared_obb,
+                            use_esdfs) ||
             !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_read, uid, gid,
                                       multi_user, userid, AID_EVERYBODY, 0027, derive_gid,
-                                      default_normal, use_esdfs) ||
+                                      default_normal, unshared_obb, use_esdfs) ||
             !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_write, uid, gid,
                                       multi_user, userid, AID_EVERYBODY, full_write ? 0007 : 0027,
-                                      derive_gid, default_normal, use_esdfs) ||
+                                      derive_gid, default_normal, unshared_obb, use_esdfs) ||
             !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_full, uid, gid,
                                       multi_user, userid, AID_EVERYBODY, 0007, derive_gid,
-                                      default_normal, use_esdfs)) {
+                                      default_normal, unshared_obb, use_esdfs)) {
             LOG(FATAL) << "failed to sdcardfs_setup";
         }
     } else {
@@ -184,16 +194,17 @@
         // the Android directories are masked off to a single user
         // deep inside attr_from_stat().
         if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
-                            AID_SDCARD_RW, 0006, derive_gid, default_normal, use_esdfs) ||
+                            AID_SDCARD_RW, 0006, derive_gid, default_normal, unshared_obb,
+                            use_esdfs) ||
             !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_read, uid, gid,
                                       multi_user, userid, AID_EVERYBODY, full_write ? 0027 : 0022,
-                                      derive_gid, default_normal, use_esdfs) ||
+                                      derive_gid, default_normal, unshared_obb, use_esdfs) ||
             !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_write, uid, gid,
                                       multi_user, userid, AID_EVERYBODY, full_write ? 0007 : 0022,
-                                      derive_gid, default_normal, use_esdfs) ||
+                                      derive_gid, default_normal, unshared_obb, use_esdfs) ||
             !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_full, uid, gid,
                                       multi_user, userid, AID_EVERYBODY, 0007, derive_gid,
-                                      default_normal, use_esdfs)) {
+                                      default_normal, unshared_obb, use_esdfs)) {
             LOG(FATAL) << "failed to sdcardfs_setup";
         }
     }
@@ -216,7 +227,8 @@
                << "    -U: specify user ID that owns device"
                << "    -m: source_path is multi-user"
                << "    -w: runtime write mount has full write access"
-               << "    -P  preserve owners on the lower file system";
+               << "    -P: preserve owners on the lower file system"
+               << "    -o: obb dir doesn't need to be shared between users";
     return 1;
 }
 
@@ -230,6 +242,7 @@
     bool full_write = false;
     bool derive_gid = false;
     bool default_normal = false;
+    bool unshared_obb = false;
     int i;
     struct rlimit rlim;
     int fs_version;
@@ -238,7 +251,7 @@
     android::base::InitLogging(argv, android::base::LogdLogger(android::base::SYSTEM));
 
     int opt;
-    while ((opt = getopt(argc, argv, "u:g:U:mwGi")) != -1) {
+    while ((opt = getopt(argc, argv, "u:g:U:mwGio")) != -1) {
         switch (opt) {
             case 'u':
                 uid = strtoul(optarg, NULL, 10);
@@ -261,8 +274,12 @@
             case 'i':
                 default_normal = true;
                 break;
+            case 'o':
+                unshared_obb = true;
+                break;
             case '?':
             default:
+                LOG(ERROR) << "Unknown option: '" << opt << "'";
                 return usage();
         }
     }
@@ -304,6 +321,6 @@
     }
 
     run_sdcardfs(source_path, label, uid, gid, userid, multi_user, full_write, derive_gid,
-                 default_normal, !should_use_sdcardfs());
+                 default_normal, unshared_obb, !should_use_sdcardfs());
     return 1;
 }
diff --git a/trusty/storage/proxy/proxy.c b/trusty/storage/proxy/proxy.c
index 9a71ae3..c61f7d0 100644
--- a/trusty/storage/proxy/proxy.c
+++ b/trusty/storage/proxy/proxy.c
@@ -39,15 +39,29 @@
 static const char* rpmb_devname;
 static const char* ss_srv_name = STORAGE_DISK_PROXY_PORT;
 
-static const char* _sopts = "hp:d:r:";
+static enum dev_type dev_type = MMC_RPMB;
+
+static enum dev_type parse_dev_type(const char* dev_type_name) {
+    if (!strcmp(dev_type_name, "mmc")) {
+        return MMC_RPMB;
+    } else if (!strcmp(dev_type_name, "virt")) {
+        return VIRT_RPMB;
+    } else {
+        return UNKNOWN_RPMB;
+    }
+}
+
+static const char* _sopts = "hp:d:r:t:";
 static const struct option _lopts[] = {{"help", no_argument, NULL, 'h'},
                                        {"trusty_dev", required_argument, NULL, 'd'},
                                        {"data_path", required_argument, NULL, 'p'},
                                        {"rpmb_dev", required_argument, NULL, 'r'},
+                                       {"dev_type", required_argument, NULL, 't'},
                                        {0, 0, 0, 0}};
 
 static void show_usage_and_exit(int code) {
-    ALOGE("usage: storageproxyd -d <trusty_dev> -p <data_path> -r <rpmb_dev>\n");
+    ALOGE("usage: storageproxyd -d <trusty_dev> -p <data_path> -r <rpmb_dev> -t <dev_type>\n");
+    ALOGE("Available dev types: mmc, virt\n");
     exit(code);
 }
 
@@ -195,6 +209,14 @@
                 rpmb_devname = strdup(optarg);
                 break;
 
+            case 't':
+                dev_type = parse_dev_type(optarg);
+                if (dev_type == UNKNOWN_RPMB) {
+                    ALOGE("Unrecognized dev type: %s\n", optarg);
+                    show_usage_and_exit(EXIT_FAILURE);
+                }
+                break;
+
             default:
                 ALOGE("unrecognized option (%c):\n", opt);
                 show_usage_and_exit(EXIT_FAILURE);
@@ -226,7 +248,7 @@
     if (rc < 0) return EXIT_FAILURE;
 
     /* open rpmb device */
-    rc = rpmb_open(rpmb_devname);
+    rc = rpmb_open(rpmb_devname, dev_type);
     if (rc < 0) return EXIT_FAILURE;
 
     /* connect to Trusty secure storage server */
diff --git a/trusty/storage/proxy/rpmb.c b/trusty/storage/proxy/rpmb.c
index e706d0a..29827e2 100644
--- a/trusty/storage/proxy/rpmb.c
+++ b/trusty/storage/proxy/rpmb.c
@@ -51,6 +51,7 @@
 
 static int rpmb_fd = -1;
 static uint8_t read_buf[4096];
+static enum dev_type dev_type = UNKNOWN_RPMB;
 
 #ifdef RPMB_DEBUG
 
@@ -68,36 +69,16 @@
 
 #endif
 
-int rpmb_send(struct storage_msg* msg, const void* r, size_t req_len) {
-    int rc;
+static int send_mmc_rpmb_req(int mmc_fd, const struct storage_rpmb_send_req* req) {
     struct {
         struct mmc_ioc_multi_cmd multi;
         struct mmc_ioc_cmd cmd_buf[3];
     } mmc = {};
     struct mmc_ioc_cmd* cmd = mmc.multi.cmds;
-    const struct storage_rpmb_send_req* req = r;
-
-    if (req_len < sizeof(*req)) {
-        ALOGW("malformed rpmb request: invalid length (%zu < %zu)\n", req_len, sizeof(*req));
-        msg->result = STORAGE_ERR_NOT_VALID;
-        goto err_response;
-    }
-
-    size_t expected_len = sizeof(*req) + req->reliable_write_size + req->write_size;
-    if (req_len != expected_len) {
-        ALOGW("malformed rpmb request: invalid length (%zu != %zu)\n", req_len, expected_len);
-        msg->result = STORAGE_ERR_NOT_VALID;
-        goto err_response;
-    }
+    int rc;
 
     const uint8_t* write_buf = req->payload;
     if (req->reliable_write_size) {
-        if ((req->reliable_write_size % MMC_BLOCK_SIZE) != 0) {
-            ALOGW("invalid reliable write size %u\n", req->reliable_write_size);
-            msg->result = STORAGE_ERR_NOT_VALID;
-            goto err_response;
-        }
-
         cmd->write_flag = MMC_WRITE_FLAG_RELW;
         cmd->opcode = MMC_WRITE_MULTIPLE_BLOCK;
         cmd->flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
@@ -114,12 +95,6 @@
     }
 
     if (req->write_size) {
-        if ((req->write_size % MMC_BLOCK_SIZE) != 0) {
-            ALOGW("invalid write size %u\n", req->write_size);
-            msg->result = STORAGE_ERR_NOT_VALID;
-            goto err_response;
-        }
-
         cmd->write_flag = MMC_WRITE_FLAG_W;
         cmd->opcode = MMC_WRITE_MULTIPLE_BLOCK;
         cmd->flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
@@ -136,12 +111,6 @@
     }
 
     if (req->read_size) {
-        if (req->read_size % MMC_BLOCK_SIZE != 0 || req->read_size > sizeof(read_buf)) {
-            ALOGE("%s: invalid read size %u\n", __func__, req->read_size);
-            msg->result = STORAGE_ERR_NOT_VALID;
-            goto err_response;
-        }
-
         cmd->write_flag = MMC_WRITE_FLAG_R;
         cmd->opcode = MMC_READ_MULTIPLE_BLOCK;
         cmd->flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC, cmd->blksz = MMC_BLOCK_SIZE;
@@ -154,9 +123,92 @@
         cmd++;
     }
 
-    rc = ioctl(rpmb_fd, MMC_IOC_MULTI_CMD, &mmc.multi);
+    rc = ioctl(mmc_fd, MMC_IOC_MULTI_CMD, &mmc.multi);
     if (rc < 0) {
         ALOGE("%s: mmc ioctl failed: %d, %s\n", __func__, rc, strerror(errno));
+    }
+    return rc;
+}
+
+static int send_virt_rpmb_req(int rpmb_fd, void* read_buf, size_t read_size, const void* payload,
+                              size_t payload_size) {
+    int rc;
+    uint16_t res_count = read_size / MMC_BLOCK_SIZE;
+    uint16_t cmd_count = payload_size / MMC_BLOCK_SIZE;
+    rc = write(rpmb_fd, &res_count, sizeof(res_count));
+    if (rc < 0) {
+        return rc;
+    }
+    rc = write(rpmb_fd, &cmd_count, sizeof(cmd_count));
+    if (rc < 0) {
+        return rc;
+    }
+    rc = write(rpmb_fd, payload, payload_size);
+    if (rc < 0) {
+        return rc;
+    }
+    rc = read(rpmb_fd, read_buf, read_size);
+    return rc;
+}
+
+int rpmb_send(struct storage_msg* msg, const void* r, size_t req_len) {
+    int rc;
+    const struct storage_rpmb_send_req* req = r;
+
+    if (req_len < sizeof(*req)) {
+        ALOGW("malformed rpmb request: invalid length (%zu < %zu)\n", req_len, sizeof(*req));
+        msg->result = STORAGE_ERR_NOT_VALID;
+        goto err_response;
+    }
+
+    size_t expected_len = sizeof(*req) + req->reliable_write_size + req->write_size;
+    if (req_len != expected_len) {
+        ALOGW("malformed rpmb request: invalid length (%zu != %zu)\n", req_len, expected_len);
+        msg->result = STORAGE_ERR_NOT_VALID;
+        goto err_response;
+    }
+
+    if ((req->reliable_write_size % MMC_BLOCK_SIZE) != 0) {
+        ALOGW("invalid reliable write size %u\n", req->reliable_write_size);
+        msg->result = STORAGE_ERR_NOT_VALID;
+        goto err_response;
+    }
+
+    if ((req->write_size % MMC_BLOCK_SIZE) != 0) {
+        ALOGW("invalid write size %u\n", req->write_size);
+        msg->result = STORAGE_ERR_NOT_VALID;
+        goto err_response;
+    }
+
+    if (req->read_size % MMC_BLOCK_SIZE != 0 || req->read_size > sizeof(read_buf)) {
+        ALOGE("%s: invalid read size %u\n", __func__, req->read_size);
+        msg->result = STORAGE_ERR_NOT_VALID;
+        goto err_response;
+    }
+
+    if (dev_type == MMC_RPMB) {
+        rc = send_mmc_rpmb_req(rpmb_fd, req);
+        if (rc < 0) {
+            msg->result = STORAGE_ERR_GENERIC;
+            goto err_response;
+        }
+    } else if (dev_type == VIRT_RPMB) {
+        size_t payload_size = req->reliable_write_size + req->write_size;
+        rc = send_virt_rpmb_req(rpmb_fd, read_buf, req->read_size, req->payload, payload_size);
+        if (rc < 0) {
+            ALOGE("send_virt_rpmb_req failed: %d, %s\n", rc, strerror(errno));
+            msg->result = STORAGE_ERR_GENERIC;
+            goto err_response;
+        }
+        if (rc != req->read_size) {
+            ALOGE("send_virt_rpmb_req got incomplete response: "
+                  "(size %d, expected %d)\n",
+                  rc, req->read_size);
+            msg->result = STORAGE_ERR_GENERIC;
+            goto err_response;
+        }
+    } else {
+        ALOGE("Unsupported dev_type\n");
         msg->result = STORAGE_ERR_GENERIC;
         goto err_response;
     }
@@ -178,8 +230,9 @@
     return ipc_respond(msg, NULL, 0);
 }
 
-int rpmb_open(const char* rpmb_devname) {
+int rpmb_open(const char* rpmb_devname, enum dev_type open_dev_type) {
     int rc;
+    dev_type = open_dev_type;
 
     rc = open(rpmb_devname, O_RDWR, 0);
     if (rc < 0) {
diff --git a/trusty/storage/proxy/rpmb.h b/trusty/storage/proxy/rpmb.h
index 5107361..4c330c9 100644
--- a/trusty/storage/proxy/rpmb.h
+++ b/trusty/storage/proxy/rpmb.h
@@ -18,6 +18,8 @@
 #include <stdint.h>
 #include <trusty/interface/storage.h>
 
-int rpmb_open(const char* rpmb_devname);
+enum dev_type { UNKNOWN_RPMB, MMC_RPMB, VIRT_RPMB };
+
+int rpmb_open(const char* rpmb_devname, enum dev_type dev_type);
 int rpmb_send(struct storage_msg* msg, const void* r, size_t req_len);
 void rpmb_close(void);