diff --git a/include/bootimg/bootimg.h b/include/bootimg/bootimg.h
index 881f8d6..784499e 100644
--- a/include/bootimg/bootimg.h
+++ b/include/bootimg/bootimg.h
@@ -335,11 +335,14 @@
  * +------------------------+
  * | vendor ramdisk table   | r pages
  * +------------------------+
+ * | bootconfig             | s pages
+ * +------------------------+
  *
- * o = (2124 + page_size - 1) / page_size
+ * o = (2128 + page_size - 1) / page_size
  * p = (vendor_ramdisk_size + page_size - 1) / page_size
  * q = (dtb_size + page_size - 1) / page_size
  * r = (vendor_ramdisk_table_size + page_size - 1) / page_size
+ * s = (vendor_bootconfig_size + page_size - 1) / page_size
  *
  * Note that in version 4 of the vendor boot image, multiple vendor ramdisks can
  * be included in the vendor boot image. The bootloader can select a subset of
@@ -364,6 +367,12 @@
  *    - VENDOR_RAMDISK_TYPE_DLKM ramdisk contains dynamic loadable kernel
  *      modules.
  *
+ * Version 4 of the vendor boot image also adds a bootconfig section to the end
+ * of the image. This section contains Boot Configuration parameters known at
+ * build time. The bootloader is responsible for placing this section directly
+ * after the generic ramdisk, followed by the bootconfig trailer, before
+ * entering the kernel.
+ *
  * 0. all entities in the boot image are 4096-byte aligned in flash, all
  *    entities in the vendor boot image are page_size (determined by the vendor
  *    and specified in the vendor boot image header) aligned in flash
@@ -373,8 +382,10 @@
  * 3. load the vendor ramdisks at ramdisk_addr
  * 4. load the generic ramdisk immediately following the vendor ramdisk in
  *    memory
- * 5. set up registers for kernel entry as required by your architecture
- * 6. if the platform has a second stage bootloader jump to it (must be
+ * 5. load the bootconfig immediately following the generic ramdisk. Add
+ *    additional bootconfig parameters followed by the bootconfig trailer.
+ * 6. set up registers for kernel entry as required by your architecture
+ * 7. if the platform has a second stage bootloader jump to it (must be
  *    contained outside boot and vendor boot partitions), otherwise
  *    jump to kernel_addr
  */
@@ -385,6 +396,7 @@
     uint32_t vendor_ramdisk_table_size; /* size in bytes for the vendor ramdisk table */
     uint32_t vendor_ramdisk_table_entry_num; /* number of entries in the vendor ramdisk table */
     uint32_t vendor_ramdisk_table_entry_size; /* size in bytes for a vendor ramdisk table entry */
+    uint32_t bootconfig_size; /* size in bytes for the bootconfig section */
 } __attribute__((packed));
 
 struct vendor_ramdisk_table_entry_v4 {
diff --git a/mkbootimg.py b/mkbootimg.py
index 0f7634f..a3f39dc 100755
--- a/mkbootimg.py
+++ b/mkbootimg.py
@@ -33,7 +33,7 @@
 
 VENDOR_BOOT_MAGIC = 'VNDRBOOT'
 VENDOR_BOOT_IMAGE_HEADER_V3_SIZE = 2112
-VENDOR_BOOT_IMAGE_HEADER_V4_SIZE = 2124
+VENDOR_BOOT_IMAGE_HEADER_V4_SIZE = 2128
 
 VENDOR_RAMDISK_TYPE_NONE = 0
 VENDOR_RAMDISK_TYPE_PLATFORM = 1
@@ -148,7 +148,8 @@
         args.vendor_boot.write(pack('I', args.vendor_ramdisk_table_entry_num))
         # vendor ramdisk table entry size in bytes
         args.vendor_boot.write(pack('I', VENDOR_RAMDISK_TABLE_ENTRY_V4_SIZE))
-
+        # bootconfig section size in bytes
+        args.vendor_boot.write(pack('I', filesize(args.vendor_bootconfig)))
     pad_file(args.vendor_boot, args.pagesize)
 
 
@@ -488,6 +489,8 @@
                         help='vendor boot output file name')
     parser.add_argument('--vendor_ramdisk', type=FileType('rb'),
                         help='path to the vendor ramdisk')
+    parser.add_argument('--vendor_bootconfig', type=FileType('rb'),
+                        help='path to the vendor bootconfig file')
 
     args, extra_args = parser.parse_known_args()
     if args.vendor_boot is not None and args.header_version > 3:
@@ -514,6 +517,8 @@
         builder.write_ramdisks_padded(args.vendor_boot, args.pagesize)
         write_padded_file(args.vendor_boot, args.dtb, args.pagesize)
         builder.write_entries_padded(args.vendor_boot, args.pagesize)
+        write_padded_file(args.vendor_boot, args.vendor_bootconfig,
+            args.pagesize)
     else:
         write_padded_file(args.vendor_boot, args.vendor_ramdisk, args.pagesize)
         write_padded_file(args.vendor_boot, args.dtb, args.pagesize)
diff --git a/tests/mkbootimg_test.py b/tests/mkbootimg_test.py
index e7794b7..9829ed4 100644
--- a/tests/mkbootimg_test.py
+++ b/tests/mkbootimg_test.py
@@ -14,6 +14,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+"""Tests mkbootimg and unpack_bootimg."""
+
 import json
 import os
 import subprocess
@@ -55,8 +57,12 @@
         with tempfile.TemporaryDirectory() as temp_out_dir:
             vendor_boot_img = os.path.join(temp_out_dir, 'vendor_boot.img')
             dtb = create_blank_file(os.path.join(temp_out_dir, 'dtb'), 0x1000)
-            ramdisk1 = create_blank_file(os.path.join(temp_out_dir, 'ramdisk1'), 0x1000)
-            ramdisk2 = create_blank_file(os.path.join(temp_out_dir, 'ramdisk2'), 0x2000)
+            ramdisk1 = create_blank_file(os.path.join(temp_out_dir, 'ramdisk1'),
+                0x1000)
+            ramdisk2 = create_blank_file(os.path.join(temp_out_dir, 'ramdisk2'),
+                0x2000)
+            bootconfig = create_blank_file(os.path.join(temp_out_dir,
+                'bootconfig'), 0x1000)
             mkbootimg_cmds = [
                 'mkbootimg',
                 '--header_version', '4',
@@ -70,6 +76,7 @@
                 '--board_id0', '0xC0FFEE',
                 '--board_id15', '0x15151515',
                 '--vendor_ramdisk_fragment', ramdisk2,
+                '--vendor_bootconfig', bootconfig,
             ]
             unpack_bootimg_cmds = [
                 'unpack_bootimg',
@@ -92,6 +99,7 @@
                 '0x00000000, 0x00000000, 0x00000000, 0x00000000,',
                 '0x00000000, 0x00000000, 0x00000000, 0x00000000,',
                 '0x00000000, 0x00000000, 0x00000000, 0x15151515,',
+                'vendor bootconfig size: 4096',
             ]
 
             subprocess.run(mkbootimg_cmds, check=True)
@@ -113,8 +121,10 @@
         """Tests mkbootimg_args.json when unpacking a boot image version 3."""
         with tempfile.TemporaryDirectory() as temp_out_dir:
             boot_img = os.path.join(temp_out_dir, 'boot.img')
-            kernel = create_blank_file(os.path.join(temp_out_dir, 'kernel'), 0x1000)
-            ramdisk = create_blank_file(os.path.join(temp_out_dir, 'ramdisk'), 0x1000)
+            kernel = create_blank_file(os.path.join(temp_out_dir, 'kernel'),
+                0x1000)
+            ramdisk = create_blank_file(os.path.join(temp_out_dir, 'ramdisk'),
+                0x1000)
             mkbootimg_cmds = [
                 'mkbootimg',
                 '--header_version', '3',
@@ -148,11 +158,14 @@
                                  expected_mkbootimg_args)
 
     def test_unpack_vendor_boot_image_v3_json_args(self):
-        """Tests mkbootimg_args.json when unpacking a vendor boot image version 3."""
+        """Tests mkbootimg_args.json when unpacking a vendor boot image version
+        3.
+        """
         with tempfile.TemporaryDirectory() as temp_out_dir:
             vendor_boot_img = os.path.join(temp_out_dir, 'vendor_boot.img')
             dtb = create_blank_file(os.path.join(temp_out_dir, 'dtb'), 0x1000)
-            ramdisk = create_blank_file(os.path.join(temp_out_dir, 'ramdisk'), 0x1000)
+            ramdisk = create_blank_file(os.path.join(temp_out_dir, 'ramdisk'),
+                0x1000)
             mkbootimg_cmds = [
                 'mkbootimg',
                 '--header_version', '3',
diff --git a/unpack_bootimg.py b/unpack_bootimg.py
index 983d647..f5e7238 100755
--- a/unpack_bootimg.py
+++ b/unpack_bootimg.py
@@ -284,6 +284,9 @@
         vendor_ramdisk_table_size = unpack('I', args.boot_img.read(4))[0]
         vendor_ramdisk_table_entry_num = unpack('I', args.boot_img.read(4))[0]
         vendor_ramdisk_table_entry_size = unpack('I', args.boot_img.read(4))[0]
+        num_vendor_ramdisk_table_pages = get_number_of_pages(
+            vendor_ramdisk_table_size, page_size)
+        vendor_bootconfig_size = unpack('I', args.boot_img.read(4))[0]
         vendor_ramdisk_table_offset = page_size * (
             num_boot_header_pages + num_boot_ramdisk_pages + num_boot_dtb_pages)
         print('vendor ramdisk table size: {}'.format(vendor_ramdisk_table_size))
@@ -319,6 +322,12 @@
             image_info_list.append((ramdisk_offset_base + ramdisk_offset,
                                     ramdisk_size, output_ramdisk_name))
         print(']')
+        bootconfig_offset = page_size * (num_boot_header_pages
+            + num_boot_ramdisk_pages + num_boot_dtb_pages
+            + num_vendor_ramdisk_table_pages)
+        image_info_list.append((bootconfig_offset, vendor_bootconfig_size,
+            'bootconfig'))
+        print('vendor bootconfig size: {}'.format(vendor_bootconfig_size))
     else:
         image_info_list.append(
             (ramdisk_offset_base, ramdisk_size, 'vendor_ramdisk'))