diff --git a/adb/fastdeploy/Android.bp b/adb/fastdeploy/Android.bp
index 400b12f..1ba0de0 100644
--- a/adb/fastdeploy/Android.bp
+++ b/adb/fastdeploy/Android.bp
@@ -22,6 +22,9 @@
     wrapper: "deployagent/deployagent.sh",
     proto: {
         type: "lite",
+    },
+    dex_preopt: {
+        enabled: false,
     }
 }
 
diff --git a/fs_mgr/Android.bp b/fs_mgr/Android.bp
index d9f2837..974e13e 100644
--- a/fs_mgr/Android.bp
+++ b/fs_mgr/Android.bp
@@ -59,6 +59,7 @@
         "libfs_avb",
         "libfstab",
         "libdm",
+        "libgsi",
     ],
     export_static_lib_headers: [
         "libfs_avb",
@@ -105,5 +106,8 @@
         },
     },
     export_include_dirs: ["include_fstab"],
-    header_libs: ["libbase_headers"],
+    header_libs: [
+        "libbase_headers",
+        "libgsi_headers",
+    ],
 }
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 19445c8..70a1045 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -79,6 +79,7 @@
 
 #define ZRAM_CONF_DEV   "/sys/block/zram0/disksize"
 #define ZRAM_CONF_MCS   "/sys/block/zram0/max_comp_streams"
+#define ZRAM_BACK_DEV   "/sys/block/zram0/backing_dev"
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
@@ -1373,6 +1374,70 @@
     return 0;
 }
 
+static bool InstallZramDevice(const std::string& device) {
+    if (!android::base::WriteStringToFile(device, ZRAM_BACK_DEV)) {
+        PERROR << "Cannot write " << device << " in: " << ZRAM_BACK_DEV;
+        return false;
+    }
+    LINFO << "Success to set " << device << " to " << ZRAM_BACK_DEV;
+    return true;
+}
+
+static bool PrepareZramDevice(const std::string& loop, off64_t size, const std::string& bdev) {
+    if (loop.empty() && bdev.empty()) return true;
+
+    if (bdev.length()) {
+        return InstallZramDevice(bdev);
+    }
+
+    // Get free loopback
+    unique_fd loop_fd(TEMP_FAILURE_RETRY(open("/dev/loop-control", O_RDWR | O_CLOEXEC)));
+    if (loop_fd.get() == -1) {
+        PERROR << "Cannot open loop-control";
+        return false;
+    }
+
+    int num = ioctl(loop_fd.get(), LOOP_CTL_GET_FREE);
+    if (num == -1) {
+        PERROR << "Cannot get free loop slot";
+        return false;
+    }
+
+    // Prepare target path
+    unique_fd target_fd(TEMP_FAILURE_RETRY(open(loop.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0664)));
+    if (target_fd.get() == -1) {
+        PERROR << "Cannot open target path: " << loop;
+        return false;
+    }
+    if (fallocate(target_fd.get(), 0, 0, size) < 0) {
+        PERROR << "Cannot truncate target path: " << loop;
+        return false;
+    }
+
+    // Connect loopback (device_fd) to target path (target_fd)
+    std::string device = android::base::StringPrintf("/dev/block/loop%d", num);
+    unique_fd device_fd(TEMP_FAILURE_RETRY(open(device.c_str(), O_RDWR | O_CLOEXEC)));
+    if (device_fd.get() == -1) {
+        PERROR << "Cannot open /dev/block/loop" << num;
+        return false;
+    }
+
+    if (ioctl(device_fd.get(), LOOP_SET_FD, target_fd.get())) {
+        PERROR << "Cannot set loopback to target path";
+        return false;
+    }
+
+    // set block size & direct IO
+    if (ioctl(device_fd.get(), LOOP_SET_BLOCK_SIZE, 4096)) {
+        PWARNING << "Cannot set 4KB blocksize to /dev/block/loop" << num;
+    }
+    if (ioctl(device_fd.get(), LOOP_SET_DIRECT_IO, 1)) {
+        PWARNING << "Cannot set direct_io to /dev/block/loop" << num;
+    }
+
+    return InstallZramDevice(device);
+}
+
 bool fs_mgr_swapon_all(const Fstab& fstab) {
     bool ret = true;
     for (const auto& entry : fstab) {
@@ -1381,6 +1446,10 @@
             continue;
         }
 
+        if (!PrepareZramDevice(entry.zram_loopback_path, entry.zram_loopback_size, entry.zram_backing_dev_path)) {
+            LERROR << "Skipping losetup for '" << entry.blk_device << "'";
+        }
+
         if (entry.zram_size > 0) {
             // A zram_size was specified, so we need to configure the
             // device.  There is no point in having multiple zram devices
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index 53b47be..c9f34a7 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -28,8 +28,10 @@
 #include <vector>
 
 #include <android-base/file.h>
+#include <android-base/parseint.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <libgsi/libgsi.h>
 
 #include "fs_mgr_priv.h"
 
@@ -43,6 +45,9 @@
     std::string key_dir;
     std::string verity_loc;
     std::string sysfs_path;
+    std::string zram_loopback_path;
+    uint64_t zram_loopback_size = 512 * 1024 * 1024; // 512MB by default
+    std::string zram_backing_dev_path;
     off64_t part_length = 0;
     std::string label;
     int partnum = -1;
@@ -117,6 +122,9 @@
         {"checkpoint=block", MF_CHECKPOINT_BLK},
         {"checkpoint=fs", MF_CHECKPOINT_FS},
         {"slotselect_other", MF_SLOTSELECT_OTHER},
+        {"zram_loopback_path=", MF_ZRAM_LOOPBACK_PATH},
+        {"zram_loopback_size=", MF_ZRAM_LOOPBACK_SIZE},
+        {"zram_backing_dev_path=", MF_ZRAM_BACKING_DEV_PATH},
         {0, 0},
 };
 
@@ -344,6 +352,16 @@
                 } else if (flag == MF_SYSFS) {
                     /* The path to trigger device gc by idle-maint of vold. */
                     flag_vals->sysfs_path = arg;
+                } else if (flag == MF_ZRAM_LOOPBACK_PATH) {
+                    /* The path to use loopback for zram. */
+                    flag_vals->zram_loopback_path = arg;
+                } else if (flag == MF_ZRAM_LOOPBACK_SIZE) {
+                    if (!android::base::ParseByteCount(arg, &flag_vals->zram_loopback_size)) {
+                        LERROR << "Warning: zram_loopback_size = flag malformed";
+                    }
+                } else if (flag == MF_ZRAM_BACKING_DEV_PATH) {
+                    /* The path to use loopback for zram. */
+                    flag_vals->zram_backing_dev_path = arg;
                 }
                 break;
             }
@@ -569,6 +587,9 @@
         entry.logical_blk_size = flag_vals.logical_blk_size;
         entry.sysfs_path = std::move(flag_vals.sysfs_path);
         entry.vbmeta_partition = std::move(flag_vals.vbmeta_partition);
+        entry.zram_loopback_path = std::move(flag_vals.zram_loopback_path);
+        entry.zram_loopback_size = std::move(flag_vals.zram_loopback_size);
+        entry.zram_backing_dev_path = std::move(flag_vals.zram_backing_dev_path);
         if (entry.fs_mgr_flags.logical) {
             entry.logical_partition_name = entry.blk_device;
         }
@@ -638,6 +659,35 @@
     return boot_devices;
 }
 
+static void EraseFstabEntry(Fstab* fstab, const std::string& mount_point) {
+    auto iter = std::remove_if(fstab->begin(), fstab->end(),
+                               [&](const auto& entry) { return entry.mount_point == mount_point; });
+    fstab->erase(iter, fstab->end());
+}
+
+static void TransformFstabForGsi(Fstab* fstab) {
+    EraseFstabEntry(fstab, "/system");
+    EraseFstabEntry(fstab, "/data");
+
+    fstab->emplace_back(BuildGsiSystemFstabEntry());
+
+    constexpr uint32_t kFlags = MS_NOATIME | MS_NOSUID | MS_NODEV;
+
+    FstabEntry userdata = {
+            .blk_device = "userdata_gsi",
+            .mount_point = "/data",
+            .fs_type = "ext4",
+            .flags = kFlags,
+            .reserved_size = 128 * 1024 * 1024,
+    };
+    userdata.fs_mgr_flags.wait = true;
+    userdata.fs_mgr_flags.check = true;
+    userdata.fs_mgr_flags.logical = true;
+    userdata.fs_mgr_flags.quota = true;
+    userdata.fs_mgr_flags.late_mount = true;
+    fstab->emplace_back(userdata);
+}
+
 bool ReadFstabFromFile(const std::string& path, Fstab* fstab) {
     auto fstab_file = std::unique_ptr<FILE, decltype(&fclose)>{fopen(path.c_str(), "re"), fclose};
     if (!fstab_file) {
@@ -645,10 +695,15 @@
         return false;
     }
 
-    if (!fs_mgr_read_fstab_file(fstab_file.get(), path == "/proc/mounts", fstab)) {
+    bool is_proc_mounts = path == "/proc/mounts";
+
+    if (!fs_mgr_read_fstab_file(fstab_file.get(), is_proc_mounts, fstab)) {
         LERROR << __FUNCTION__ << "(): failed to load fstab from : '" << path << "'";
         return false;
     }
+    if (!is_proc_mounts && !access(android::gsi::kGsiBootedIndicatorFile, F_OK)) {
+        TransformFstabForGsi(fstab);
+    }
 
     return true;
 }
@@ -776,6 +831,8 @@
         free(fstab->recs[i].key_dir);
         free(fstab->recs[i].label);
         free(fstab->recs[i].sysfs_path);
+        free(fstab->recs[i].zram_loopback_path);
+        free(fstab->recs[i].zram_backing_dev_path);
     }
 
     /* Free the fstab_recs array created by calloc(3) */
@@ -873,6 +930,9 @@
     entry.erase_blk_size = fstab_rec->erase_blk_size;
     entry.logical_blk_size = fstab_rec->logical_blk_size;
     entry.sysfs_path = fstab_rec->sysfs_path;
+    entry.zram_loopback_path = fstab_rec->zram_loopback_path;
+    entry.zram_loopback_size = fstab_rec->zram_loopback_size;
+    entry.zram_backing_dev_path = fstab_rec->zram_backing_dev_path;
 
     return entry;
 }
@@ -916,6 +976,9 @@
         legacy_fstab->recs[i].erase_blk_size = fstab[i].erase_blk_size;
         legacy_fstab->recs[i].logical_blk_size = fstab[i].logical_blk_size;
         legacy_fstab->recs[i].sysfs_path = strdup(fstab[i].sysfs_path.c_str());
+        legacy_fstab->recs[i].zram_loopback_path = strdup(fstab[i].zram_loopback_path.c_str());
+        legacy_fstab->recs[i].zram_loopback_size = fstab[i].zram_loopback_size;
+        legacy_fstab->recs[i].zram_backing_dev_path = strdup(fstab[i].zram_backing_dev_path.c_str());
     }
     return legacy_fstab;
 }
@@ -1023,3 +1086,17 @@
 int fs_mgr_is_checkpoint_blk(const struct fstab_rec* fstab) {
     return fstab->fs_mgr_flags & MF_CHECKPOINT_BLK;
 }
+
+FstabEntry BuildGsiSystemFstabEntry() {
+    FstabEntry system = {
+            .blk_device = "system_gsi",
+            .mount_point = "/system",
+            .fs_type = "ext4",
+            .flags = MS_RDONLY,
+            .fs_options = "barrier=1",
+    };
+    system.fs_mgr_flags.wait = true;
+    system.fs_mgr_flags.logical = true;
+    system.fs_mgr_flags.first_stage_mount = true;
+    return system;
+}
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 6364ca9..0f89467 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -48,6 +48,7 @@
 #include <fs_mgr_overlayfs.h>
 #include <fstab/fstab.h>
 #include <libdm/dm.h>
+#include <libgsi/libgsi.h>
 #include <liblp/builder.h>
 #include <liblp/liblp.h>
 
@@ -802,8 +803,9 @@
 bool fs_mgr_overlayfs_invalid() {
     if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) return true;
 
-    // in recovery or fastbootd mode, not allowed!
+    // in recovery, fastbootd, or gsi mode, not allowed!
     if (fs_mgr_access("/system/bin/recovery")) return true;
+    if (android::gsi::IsGsiRunning()) return true;
 
     return false;
 }
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index 7842ca2..39ceff7 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -122,6 +122,12 @@
                           0x80000000
 #define MF_SLOTSELECT_OTHER  \
                          0x100000000
+#define MF_ZRAM_LOOPBACK_PATH    \
+                         0x200000000
+#define MF_ZRAM_LOOPBACK_SIZE    \
+                         0x400000000
+#define MF_ZRAM_BACKING_DEV_PATH \
+                         0x800000000
 // clang-format on
 
 #define DM_BUF_SIZE 4096
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index 0997254..5d8496d 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -59,6 +59,9 @@
     off64_t erase_blk_size;
     off64_t logical_blk_size;
     char* sysfs_path;
+    char* zram_loopback_path;
+    uint64_t zram_loopback_size;
+    char* zram_backing_dev_path;
 };
 
 struct fstab* fs_mgr_read_fstab_default();
@@ -119,6 +122,9 @@
     off64_t logical_blk_size = 0;
     std::string sysfs_path;
     std::string vbmeta_partition;
+    std::string zram_loopback_path;
+    uint64_t zram_loopback_size;
+    std::string zram_backing_dev_path;
 
     // TODO: Remove this union once fstab_rec is deprecated. It only serves as a
     // convenient way to convert between fstab_rec::fs_mgr_flags and these bools.
@@ -187,3 +193,6 @@
 FstabEntry FstabRecToFstabEntry(const fstab_rec* fstab_rec);
 Fstab LegacyFstabToFstab(const struct fstab* legacy_fstab);
 fstab* FstabToLegacyFstab(const Fstab& fstab);
+
+// Helper method to build a GSI fstab entry for mounting /system.
+FstabEntry BuildGsiSystemFstabEntry();
diff --git a/init/Android.bp b/init/Android.bp
index c920dc2..3369fb9 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -77,6 +77,7 @@
         "libext4_utils",
         "libfs_mgr",
         "libfscrypt",
+        "libgsi",
         "libhidl-gen-utils",
         "libkeyutils",
         "liblog",
diff --git a/init/Android.mk b/init/Android.mk
index bdd0301..69c63e1 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -91,6 +91,7 @@
     libz \
     libselinux \
     libcap \
+    libgsi \
 
 LOCAL_SANITIZE := signed-integer-overflow
 # First stage init is weird: it may start without stdout/stderr, and no /proc.
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 43a520f..e1a86e4 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -54,6 +54,7 @@
 #include <fs_mgr.h>
 #include <fscrypt/fscrypt.h>
 #include <fscrypt/fscrypt_init_extensions.h>
+#include <libgsi/libgsi.h>
 #include <selinux/android.h>
 #include <selinux/label.h>
 #include <selinux/selinux.h>
@@ -520,6 +521,9 @@
         return Success();
     } else if (code == FS_MGR_MNTALL_DEV_NEEDS_RECOVERY) {
         /* Setup a wipe via recovery, and reboot into recovery */
+        if (android::gsi::IsGsiRunning()) {
+            return Error() << "cannot wipe within GSI";
+        }
         PLOG(ERROR) << "fs_mgr_mount_all suggested recovery, so wiping data via recovery.";
         const std::vector<std::string> options = {"--wipe_data", "--reason=fs_mgr_mount_all" };
         return reboot_into_recovery(options);
@@ -1022,7 +1026,8 @@
     }
     service->AddReapCallback([reboot_reason](const siginfo_t& siginfo) {
         if (siginfo.si_code != CLD_EXITED || siginfo.si_status != 0) {
-            if (fscrypt_is_native()) {
+            // TODO (b/122850122): support this in gsi
+            if (fscrypt_is_native() && !android::gsi::IsGsiRunning()) {
                 LOG(ERROR) << "Rebooting into recovery, reason: " << reboot_reason;
                 if (auto result = reboot_into_recovery(
                             {"--prompt_and_wipe_data", "--reason="s + reboot_reason});
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index 71fe401..affa39e 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -34,6 +34,7 @@
 #include <fs_mgr.h>
 #include <fs_mgr_dm_linear.h>
 #include <fs_mgr_overlayfs.h>
+#include <libgsi/libgsi.h>
 #include <liblp/liblp.h>
 
 #include "devices.h"
@@ -79,6 +80,7 @@
     bool IsDmLinearEnabled();
     bool GetDmLinearMetadataDevice();
     bool InitDmLinearBackingDevices(const android::fs_mgr::LpMetadata& metadata);
+    void UseGsiIfPresent();
 
     ListenerAction UeventCallback(const Uevent& uevent);
 
@@ -207,6 +209,8 @@
     }
 
     required_devices_partition_names_.emplace(super_partition_name_);
+    // When booting from live GSI images, userdata is the super device.
+    required_devices_partition_names_.emplace("userdata");
     return true;
 }
 
@@ -410,6 +414,16 @@
 // this case, we mount system first then pivot to it.  From that point on,
 // we are effectively identical to a system-as-root device.
 bool FirstStageMount::TrySwitchSystemAsRoot() {
+    auto metadata_partition = std::find_if(fstab_.begin(), fstab_.end(), [](const auto& entry) {
+        return entry.mount_point == "/metadata";
+    });
+    if (metadata_partition != fstab_.end()) {
+        if (MountPartition(&(*metadata_partition))) {
+            fstab_.erase(metadata_partition);
+            UseGsiIfPresent();
+        }
+    }
+
     auto system_partition = std::find_if(fstab_.begin(), fstab_.end(), [](const auto& entry) {
         return entry.mount_point == "/system";
     });
@@ -513,6 +527,40 @@
     return true;
 }
 
+void FirstStageMount::UseGsiIfPresent() {
+    std::string metadata_file, error;
+
+    if (!android::gsi::CanBootIntoGsi(&metadata_file, &error)) {
+        LOG(INFO) << "GSI " << error << ", proceeding with normal boot";
+        return;
+    }
+
+    auto metadata = android::fs_mgr::ReadFromImageFile(metadata_file.c_str());
+    if (!metadata) {
+        LOG(ERROR) << "GSI partition layout could not be read";
+        return;
+    }
+
+    if (!android::fs_mgr::CreateLogicalPartitions(*metadata.get(), "/dev/block/by-name/userdata")) {
+        LOG(ERROR) << "GSI partition layout could not be instantiated";
+        return;
+    }
+
+    if (!android::gsi::MarkSystemAsGsi()) {
+        PLOG(ERROR) << "GSI indicator file could not be written";
+        return;
+    }
+
+    // Replace the existing system fstab entry.
+    auto system_partition = std::find_if(fstab_.begin(), fstab_.end(), [](const auto& entry) {
+        return entry.mount_point == "/system";
+    });
+    if (system_partition != fstab_.end()) {
+        fstab_.erase(system_partition);
+    }
+    fstab_.emplace_back(BuildGsiSystemFstabEntry());
+}
+
 bool FirstStageMountVBootV1::GetDmVerityDevices() {
     std::string verity_loc_device;
     need_dm_verity_ = false;
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 008a868..0aa7810 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -20,9 +20,11 @@
 #include <fcntl.h>
 #include <linux/fs.h>
 #include <mntent.h>
+#include <linux/loop.h>
 #include <sys/cdefs.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
+#include <sys/swap.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
@@ -58,6 +60,7 @@
 using android::base::Split;
 using android::base::StringPrintf;
 using android::base::Timer;
+using android::base::unique_fd;
 
 namespace android {
 namespace init {
@@ -193,7 +196,7 @@
     return true;
 }
 
-static void DumpUmountDebuggingInfo(bool dump_all) {
+static void DumpUmountDebuggingInfo() {
     int status;
     if (!security_getenforce()) {
         LOG(INFO) << "Run lsof";
@@ -202,10 +205,9 @@
                                 true, nullptr, nullptr, 0);
     }
     FindPartitionsToUmount(nullptr, nullptr, true);
-    if (dump_all) {
-        // dump current tasks, this log can be lengthy, so only dump with dump_all
-        android::base::WriteStringToFile("t", "/proc/sysrq-trigger");
-    }
+    // dump current CPU stack traces and uninterruptible tasks
+    android::base::WriteStringToFile("l", "/proc/sysrq-trigger");
+    android::base::WriteStringToFile("w", "/proc/sysrq-trigger");
 }
 
 static UmountStat UmountPartitions(std::chrono::milliseconds timeout) {
@@ -268,11 +270,11 @@
     UmountStat stat = UmountPartitions(timeout - t.duration());
     if (stat != UMOUNT_STAT_SUCCESS) {
         LOG(INFO) << "umount timeout, last resort, kill all and try";
-        if (DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(true);
+        if (DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo();
         KillAllProcesses();
         // even if it succeeds, still it is timeout and do not run fsck with all processes killed
         UmountStat st = UmountPartitions(0ms);
-        if ((st != UMOUNT_STAT_SUCCESS) && DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(false);
+        if ((st != UMOUNT_STAT_SUCCESS) && DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo();
     }
 
     if (stat == UMOUNT_STAT_SUCCESS && runFsck) {
@@ -285,6 +287,48 @@
     return stat;
 }
 
+// zram is able to use backing device on top of a loopback device.
+// In order to unmount /data successfully, we have to kill the loopback device first
+#define ZRAM_DEVICE   "/dev/block/zram0"
+#define ZRAM_RESET    "/sys/block/zram0/reset"
+#define ZRAM_BACK_DEV "/sys/block/zram0/backing_dev"
+static void KillZramBackingDevice() {
+    std::string backing_dev;
+    if (!android::base::ReadFileToString(ZRAM_BACK_DEV, &backing_dev)) return;
+
+    if (!android::base::StartsWith(backing_dev, "/dev/block/loop")) return;
+
+    // cut the last "\n"
+    backing_dev.erase(backing_dev.length() - 1);
+
+    // shutdown zram handle
+    Timer swap_timer;
+    LOG(INFO) << "swapoff() start...";
+    if (swapoff(ZRAM_DEVICE) == -1) {
+        LOG(ERROR) << "zram_backing_dev: swapoff (" << backing_dev << ")" << " failed";
+        return;
+    }
+    LOG(INFO) << "swapoff() took " << swap_timer;;
+
+    if (!android::base::WriteStringToFile("1", ZRAM_RESET)) {
+        LOG(ERROR) << "zram_backing_dev: reset (" << backing_dev << ")" << " failed";
+        return;
+    }
+
+    // clear loopback device
+    unique_fd loop(TEMP_FAILURE_RETRY(open(backing_dev.c_str(), O_RDWR | O_CLOEXEC)));
+    if (loop.get() < 0) {
+        LOG(ERROR) << "zram_backing_dev: open(" << backing_dev << ")" << " failed";
+        return;
+    }
+
+    if (ioctl(loop.get(), LOOP_CLR_FD, 0) < 0) {
+        LOG(ERROR) << "zram_backing_dev: loop_clear (" << backing_dev << ")" << " failed";
+        return;
+    }
+    LOG(INFO) << "zram_backing_dev: `" << backing_dev << "` is cleared successfully.";
+}
+
 //* Reboot / shutdown the system.
 // cmd ANDROID_RB_* as defined in android_reboot.h
 // reason Reason string like "reboot", "shutdown,userrequested"
@@ -427,6 +471,9 @@
         sync();
         LOG(INFO) << "sync() before umount took" << sync_timer;
     }
+    // 5. drop caches and disable zram backing device, if exist
+    KillZramBackingDevice();
+
     UmountStat stat = TryUmountAndFsck(runFsck, shutdown_timeout - t.duration());
     // Follow what linux shutdown is doing: one more sync with little bit delay
     {
diff --git a/libcutils/include/private/android_filesystem_config.h b/libcutils/include/private/android_filesystem_config.h
index 0723612..03edfb5 100644
--- a/libcutils/include/private/android_filesystem_config.h
+++ b/libcutils/include/private/android_filesystem_config.h
@@ -190,7 +190,8 @@
  */
 #define AID_OVERFLOWUID 65534 /* unmapped user in the user namespace */
 
-#define AID_ISOLATED_START 99000 /* start of uids for fully isolated sandboxed processes */
+/* use the ranges below to determine whether a process is isolated */
+#define AID_ISOLATED_START 90000 /* start of uids for fully isolated sandboxed processes */
 #define AID_ISOLATED_END 99999   /* end of uids for fully isolated sandboxed processes */
 
 #define AID_USER 100000        /* TODO: switch users over to AID_USER_OFFSET */