diff --git a/fastboot/fastboot.bash b/fastboot/fastboot.bash
index cb1d354..cc1366c 100644
--- a/fastboot/fastboot.bash
+++ b/fastboot/fastboot.bash
@@ -109,7 +109,7 @@
 
     cur="${COMP_WORDS[COMP_CWORD]}"
     if [[ $i -eq $COMP_CWORD ]]; then
-        partitions="boot bootloader dtbo modem odm oem product radio recovery system vbmeta vendor"
+        partitions="boot bootloader dtbo modem odm oem product radio recovery system vbmeta vendor vendor_dlkm"
         COMPREPLY=( $(compgen -W "$partitions" -- $cur) )
     else
         _fastboot_util_complete_local_file "${cur}" '!*.img'
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 86cf30d..4ca6a6a 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -166,6 +166,10 @@
                   "vendor_boot.img",  "vendor_boot.sig",
                                                       "vendor_boot",
                                                                   true,  ImageType::BootCritical },
+    { "vendor_dlkm",
+                  "vendor_dlkm.img",  "vendor_dlkm.sig",
+                                                      "vendor_dlkm",
+                                                                  true,  ImageType::Normal },
     { nullptr,    "vendor_other.img", "vendor.sig",   "vendor",   true,  ImageType::Normal },
         // clang-format on
 };
diff --git a/init/property_service.cpp b/init/property_service.cpp
index b593b62..0c4a3c4 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -632,9 +632,10 @@
     char *key, *value, *eol, *sol, *tmp, *fn;
     size_t flen = 0;
 
-    static constexpr const char* const kVendorPathPrefixes[2] = {
+    static constexpr const char* const kVendorPathPrefixes[3] = {
             "/vendor",
             "/odm",
+            "/vendor_dlkm",
     };
 
     const char* context = kInitContext;
@@ -939,6 +940,7 @@
     load_properties_from_file("/vendor/default.prop", nullptr, &properties);
     // }
     load_properties_from_file("/vendor/build.prop", nullptr, &properties);
+    load_properties_from_file("/vendor_dlkm/etc/build.prop", nullptr, &properties);
     load_properties_from_partition("odm", /* support_legacy_path_until */ 28);
     load_properties_from_partition("product", /* support_legacy_path_until */ 30);
 
diff --git a/libpixelflinger/include/pixelflinger/format.h b/libpixelflinger/include/pixelflinger/format.h
index 82eeca4..d429477 100644
--- a/libpixelflinger/include/pixelflinger/format.h
+++ b/libpixelflinger/include/pixelflinger/format.h
@@ -82,7 +82,7 @@
     GGL_INDEX_CR      = 2,
 };
 
-typedef struct {
+typedef struct GGLFormat {
 #ifdef __cplusplus
     enum {
         ALPHA   = GGL_INDEX_ALPHA,
diff --git a/libutils/String8.cpp b/libutils/String8.cpp
index d00e39c..c837891 100644
--- a/libutils/String8.cpp
+++ b/libutils/String8.cpp
@@ -424,7 +424,7 @@
     char* buf = lockBuffer(len);
     buf += start;
     while (length > 0) {
-        *buf = tolower(*buf);
+        *buf = static_cast<char>(tolower(*buf));
         buf++;
         length--;
     }
@@ -448,7 +448,7 @@
     char* buf = lockBuffer(len);
     buf += start;
     while (length > 0) {
-        *buf = toupper(*buf);
+        *buf = static_cast<char>(toupper(*buf));
         buf++;
         length--;
     }
diff --git a/rootdir/Android.mk b/rootdir/Android.mk
index a9d0ed0..ac8e847 100644
--- a/rootdir/Android.mk
+++ b/rootdir/Android.mk
@@ -120,6 +120,17 @@
 LOCAL_POST_INSTALL_CMD += ; ln -sf /vendor/odm/priv-app $(TARGET_ROOT_OUT)/odm/priv-app
 LOCAL_POST_INSTALL_CMD += ; ln -sf /vendor/odm/usr $(TARGET_ROOT_OUT)/odm/usr
 
+
+# For /vendor_dlkm partition.
+LOCAL_POST_INSTALL_CMD += ; mkdir -p $(TARGET_ROOT_OUT)/vendor_dlkm
+# For Treble Generic System Image (GSI), system-as-root GSI needs to work on
+# both devices with and without /vendor_dlkm partition. Those symlinks are for
+# devices without /vendor_dlkm partition. For devices with /vendor_dlkm
+# partition, mount vendor_dlkm.img under /vendor_dlkm will hide those symlinks.
+# Note that /vendor_dlkm/lib is omitted because vendor DLKMs should be accessed
+# via /vendor/lib/modules directly.
+LOCAL_POST_INSTALL_CMD += ; ln -sf /vendor/vendor_dlkm/etc $(TARGET_ROOT_OUT)/vendor_dlkm/etc
+
 ifdef BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
   LOCAL_POST_INSTALL_CMD += ; mkdir -p $(TARGET_ROOT_OUT)/cache
 else