Merge "fs_config: Update docs"
diff --git a/tools/fs_config/README b/tools/fs_config/README
deleted file mode 100644
index 21bdeb8..0000000
--- a/tools/fs_config/README
+++ /dev/null
@@ -1,137 +0,0 @@
- _____ _____ _____ _____ __ __ _____
-/ _ \/ __\/ _ \| _ \/ \/ \/ __\
-| _ <| __|| _ || | || \/ || __|
-\__|\_/\_____/\__|__/|_____/\__ \__/\_____/
-
-The fs_config_generator.py tool uses the platform android_filesystem_config.h and the
-TARGET_FS_CONFIG_GEN files to generate the fs_config_dirs and fs_config_files files for each
-partition, as well as passwd and group files, and the generated_oem_aid.h header.
-
-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.
-
-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 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.
-
-The parsing of the TARGET_FS_CONFIG_GEN files follows the Python ConfigParser specification, with
-the sections and fields as defined below. There are two types of sections, both sections require all
-options to be specified. The first section type is the "caps" section.
-
-The "caps" section follows the following syntax:
-
-[path]
-mode: Octal file mode
-user: AID_<user>
-group: AID_<group>
-caps: cap*
-
-Where:
-
-[path]
- The filesystem path to configure. A path ending in / is considered a dir,
- else its a file.
-
-mode:
- A valid octal file mode of at least 3 digits. If 3 is specified, it is
- prefixed with a 0, else mode is used as is.
-
-user:
- Either the C define for a valid AID or the friendly name. For instance both
- AID_RADIO and radio are acceptable. Note custom AIDs can be defined in the
- AID section documented below.
-
-group:
- Same as user.
-
-caps:
- The name as declared in
- system/core/include/private/android_filesystem_capability.h without the
- leading CAP_. Mixed case is allowed. Caps can also be the raw:
- * binary (0b0101)
- * octal (0455)
- * int (42)
- * hex (0xFF)
- For multiple caps, just separate by whitespace.
-
-It is an error to specify multiple sections with the same [path] in different
-files. Note that the same file may contain sections that override the previous
-section in Python versions <= 3.2. In Python 3.2 it's set to strict mode.
-
-
-The next section type is the "AID" section, for specifying OEM specific AIDS.
-
-The AID section follows the following syntax:
-
-[AID_<name>]
-value: <number>
-
-Where:
-
-[AID_<name>]
- The <name> can contain characters in the set uppercase, numbers
- and underscores.
-
-value:
- A valid C style number string. Hex, octal, binary and decimal are supported.
- See "caps" above for more details on number formatting.
-
-It is an error to specify multiple sections with the same [AID_<name>]. With
-the same constraints as [path] described above. It is also an error to specify
-multiple sections with the same value option. It is also an error to specify a
-value that is outside of the inclusive OEM ranges:
- * AID_OEM_RESERVED_START(2900) - AID_OEM_RESERVED_END(2999)
- * AID_OEM_RESERVED_2_START(5000) - AID_OEM_RESERVED_2_END(5999)
-
-as defined by system/core/include/private/android_filesystem_config.h.
-
-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
- ** ie foo before f*
- * lexicographical less than before other
- ** ie 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.
diff --git a/tools/fs_config/README.md b/tools/fs_config/README.md
new file mode 100644
index 0000000..bad5e10
--- /dev/null
+++ b/tools/fs_config/README.md
@@ -0,0 +1,84 @@
+# 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_dirs` and `fs_config_files` files for each partition
+* `passwd` and `group` files for each partition
+* The `generated_oem_aid.h` header
+
+## 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](https://source.android.com/devices/tech/config/filesystem#configuring-aids) 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.