75f7cf9a2d
These files were added to devices with the fs_config_files_nonsystem module in base_vendor.mk. As they are partition-specific, move them to each base_<partition>.mk file. To add the fs_config_* files to the base_<partition>.mk files, it is required to define the fs_config_* regardless of the existance of partitions. Bug: 170282998 Test: build and check if they are installed. Change-Id: Ib8a2c75e2e0e93bb7030da981494e880f8465e5a |
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|---|---|---|
| .. | ||
| end_to_end_test | ||
| Android.bp | ||
| Android.mk | ||
| fs_config.c | ||
| fs_config.go | ||
| fs_config_generator.py | ||
| OWNERS | ||
| pylintrc | ||
| README.md | ||
| test_fs_config_generator.py | ||
FS Config Generator
The fs_config_generator.py tool uses the platform android_filesystem_config.h and the
TARGET_FS_CONFIG_GEN files to generate the following:
fs_config_dirsandfs_config_filesfiles for each partitionpasswdandgroupfiles for each partition- The
generated_oem_aid.hheader
Outputs
fs_config_dirs and fs_config_files
The fs_config_dirs and fs_config_files binary files are interpreted by the libcutils
fs_config() function, along with the built-in defaults, to serve as overrides to complete the
results. The Target files are used by filesystem and adb tools to ensure that the file and directory
properties are preserved during runtime operations. The host files in the $OUT directory are used
in the final stages when building the filesystem images to set the file and directory properties.
See ./fs_config_generator.py fsconfig --help for how these files are generated.
passwd and group files
The passwd and group files are formatted as documented in man pages passwd(5) and group(5) and
used by bionic for implementing getpwnam() and related functions.
See ./fs_config_generator.py passwd --help and ./fs_config_generator.py group --help for how
these files are generated.
The generated_oem_aid.h header
The generated_oem_aid.h creates identifiers for non-platform AIDs for developers wishing to use
them in their native code. To do so, include the oemaids_headers header library in the
corresponding makefile and #include "generated_oem_aid.h" in the code wishing to use these
identifiers.
See ./fs_config_generator.py oemaid --help for how this file is generated.
Parsing
See the documentation on source.android.com for details and examples.
Ordering
Ordering within the TARGET_FS_CONFIG_GEN files is not relevant. The paths for files are sorted
like so within their respective array definition:
- specified path before prefix match
- for example: foo before f*
- lexicographical less than before other
- for example: boo before foo
Given these paths:
paths=['ac', 'a', 'acd', 'an', 'a*', 'aa', 'ac*']
The sort order would be:
paths=['a', 'aa', 'ac', 'acd', 'an', 'ac*', 'a*']
Thus the fs_config tools will match on specified paths before attempting prefix, and match on the
longest matching prefix.
The declared AIDs are sorted in ascending numerical order based on the option "value". The string representation of value is preserved. Both choices were made for maximum readability of the generated file and to line up files. Sync lines are placed with the source file as comments in the generated header file.
Unit Tests
From within the fs_config directory, unit tests can be executed like so:
$ python -m unittest test_fs_config_generator.Tests
.............
----------------------------------------------------------------------
Ran 13 tests in 0.004s
OK
One could also use nose if they would like:
$ nose2
To add new tests, simply add a test_<xxx> method to the test class. It will automatically
get picked up and added to the test suite.