Prevent AVB signing from using _RESERVED_SIZE
When AVB is enabled with PRODUCT_USE_DYNAMIC_PARTITION_SIZE, AVB
metadata (e.g., hash tree, fec metadata) will consume _RESERVED_SIZE,
resulting in smaller reserved size in file system (e.g., ext4).
Adding additional space for AVB signing and keep the _RESERVED_SIZE only
for file system. This is done by adding a function to binary search an
optimal partition size for a given image size (disk usage + _RESERVED_SIZE).
Bug: 112322265
Test: Build aosp_arm64-userdebug, calculate the running time of
AVBCalcMinPartitionSize() is about 0.3-0.4 seconds.
Test: python -m unittest test_build_image
Change-Id: I8f0051b57701d6fbba6a9db3756dd194066c74b8
diff --git a/tools/releasetools/test_build_image.py b/tools/releasetools/test_build_image.py
index 40a7c85..0aaa847 100644
--- a/tools/releasetools/test_build_image.py
+++ b/tools/releasetools/test_build_image.py
@@ -15,11 +15,15 @@
#
import filecmp
+import math
import os.path
+import random
import unittest
import common
-from build_image import CheckHeadroom, RunCommand, SetUpInDirAndFsConfig
+from build_image import (
+ AVBCalcMinPartitionSize, BLOCK_SIZE,
+ CheckHeadroom, RunCommand, SetUpInDirAndFsConfig)
class BuildImageTest(unittest.TestCase):
@@ -28,6 +32,13 @@
EXT4FS_OUTPUT = (
"Created filesystem with 2777/129024 inodes and 515099/516099 blocks")
+ def setUp(self):
+ # To test AVBCalcMinPartitionSize(), by using 200MB to 2GB image size.
+ # - 51200 = 200MB * 1024 * 1024 / 4096
+ # - 524288 = 2GB * 1024 * 1024 * 1024 / 4096
+ self._image_sizes = [BLOCK_SIZE * random.randint(51200, 524288) + offset
+ for offset in range(BLOCK_SIZE)]
+
def tearDown(self):
common.Cleanup()
@@ -176,3 +187,51 @@
self.assertIn('fs-config-system\n', fs_config_data)
self.assertIn('fs-config-root\n', fs_config_data)
self.assertEqual('/', prop_dict['mount_point'])
+
+ def test_AVBCalcMinPartitionSize_LinearFooterSize(self):
+ """Tests with footer size which is linear to partition size."""
+ for image_size in self._image_sizes:
+ for ratio in 0.95, 0.56, 0.22:
+ expected_size = common.RoundUpTo4K(int(math.ceil(image_size / ratio)))
+ self.assertEqual(
+ expected_size,
+ AVBCalcMinPartitionSize(image_size, lambda x: int(x * ratio)))
+
+ def test_AVBCalcMinPartitionSize_SlowerGrowthFooterSize(self):
+ """Tests with footer size which grows slower than partition size."""
+
+ def _SizeCalculator(partition_size):
+ """Footer size is the power of 0.95 of partition size."""
+ # Minus footer size to return max image size.
+ return partition_size - int(math.pow(partition_size, 0.95))
+
+ for image_size in self._image_sizes:
+ min_partition_size = AVBCalcMinPartitionSize(image_size, _SizeCalculator)
+ # Checks min_partition_size can accommodate image_size.
+ self.assertGreaterEqual(
+ _SizeCalculator(min_partition_size),
+ image_size)
+ # Checks min_partition_size (round to BLOCK_SIZE) is the minimum.
+ self.assertLess(
+ _SizeCalculator(min_partition_size - BLOCK_SIZE),
+ image_size)
+
+ def test_AVBCalcMinPartitionSize_FasterGrowthFooterSize(self):
+ """Tests with footer size which grows faster than partition size."""
+
+ def _SizeCalculator(partition_size):
+ """Max image size is the power of 0.95 of partition size."""
+ # Max image size grows less than partition size, which means
+ # footer size grows faster than partition size.
+ return int(math.pow(partition_size, 0.95))
+
+ for image_size in self._image_sizes:
+ min_partition_size = AVBCalcMinPartitionSize(image_size, _SizeCalculator)
+ # Checks min_partition_size can accommodate image_size.
+ self.assertGreaterEqual(
+ _SizeCalculator(min_partition_size),
+ image_size)
+ # Checks min_partition_size (round to BLOCK_SIZE) is the minimum.
+ self.assertLess(
+ _SizeCalculator(min_partition_size - BLOCK_SIZE),
+ image_size)