commit a5557671d7368538704e49e0699d46aaa73a8f36
author TreeHugger Robot <treehugger-gerrit@google.com> Mon May 18 04:37:37 2020 +0000
committer Android (Google) Code Review <android-gerrit@google.com> Mon May 18 04:37:37 2020 +0000
tree f2d9725e3b0539b9e2604e12667d997b2b5ff802
parent f6cef7237827d04a3bdbbd6c0b4a80b6601e484c
parent fecef364795d098383aaaec53f1149ceeef28a42

Merge "fastbootd: copy AVB footer on boot image to end of block device" into rvc-dev

fastboot/Android.bp

diff --git a/fastboot/Android.bp b/fastboot/Android.bp
index 884856d..a7cde68 100644
--- a/fastboot/Android.bp
+++ b/fastboot/Android.bp
@@ -148,6 +148,7 @@
     ],
 
     header_libs: [
+        "avb_headers",
         "libsnapshot_headers",
     ]
 }

fastboot/device/flashing.cpp

diff --git a/fastboot/device/flashing.cpp b/fastboot/device/flashing.cpp
index 7e7e507..a5f1223 100644
--- a/fastboot/device/flashing.cpp
+++ b/fastboot/device/flashing.cpp
@@ -31,6 +31,7 @@
 #include <ext4_utils/ext4_utils.h>
 #include <fs_mgr_overlayfs.h>
 #include <fstab/fstab.h>
+#include <libavb/libavb.h>
 #include <liblp/builder.h>
 #include <liblp/liblp.h>
 #include <libsnapshot/snapshot.h>
@@ -122,6 +123,27 @@
     }
 }
 
+static void CopyAVBFooter(std::vector<char>* data, const uint64_t block_device_size) {
+    if (data->size() < AVB_FOOTER_SIZE) {
+        return;
+    }
+    std::string footer;
+    uint64_t footer_offset = data->size() - AVB_FOOTER_SIZE;
+    for (int idx = 0; idx < AVB_FOOTER_MAGIC_LEN; idx++) {
+        footer.push_back(data->at(footer_offset + idx));
+    }
+    if (0 != footer.compare(AVB_FOOTER_MAGIC)) {
+        return;
+    }
+
+    // copy AVB footer from end of data to end of block device
+    uint64_t original_data_size = data->size();
+    data->resize(block_device_size, 0);
+    for (int idx = 0; idx < AVB_FOOTER_SIZE; idx++) {
+        data->at(block_device_size - 1 - idx) = data->at(original_data_size - 1 - idx);
+    }
+}
+
 int Flash(FastbootDevice* device, const std::string& partition_name) {
     PartitionHandle handle;
     if (!OpenPartition(device, partition_name, &handle)) {
@@ -131,8 +153,14 @@
     std::vector<char> data = std::move(device->download_data());
     if (data.size() == 0) {
         return -EINVAL;
-    } else if (data.size() > get_block_device_size(handle.fd())) {
+    }
+    uint64_t block_device_size = get_block_device_size(handle.fd());
+    if (data.size() > block_device_size) {
         return -EOVERFLOW;
+    } else if (data.size() < block_device_size &&
+               (partition_name == "boot" || partition_name == "boot_a" ||
+                partition_name == "boot_b")) {
+        CopyAVBFooter(&data, block_device_size);
     }
     WipeOverlayfsForPartition(device, partition_name);
     return FlashBlockDevice(handle.fd(), data);