Application Folder

Contents

In this file,

General
Directory Location
Application Configuration File
Suggestion for Optimizing SmartFs Ops

Outside this file,

Built-In Applications
Shell (TASH)
How to add new application

General

This folder provides various applications found in sub-directories. These applications are not inherently a part of TinyAra but are provided to help you develop your own applications. The apps/ directory is a "break away" part of the configuration that you may choose to use or not.

Directory Location

The default application directory used by the TinyAra build should be named apps/ (or apps-x.y/ where x.y is the TinyAra version number). This apps/ directory should appear in the directory tree at the same level as the TinyAra os directory. Like:

.  
|- os  
|  
`- apps

If all of the above conditions are TRUE, then TinyAra will be able to find the application directory. If your application directory has a different name or is location at a different position, then you will have to inform the TinyAra build system of that location. There are several ways to do that:

1. You can define CONFIG_APPS_DIR to be the full path to your application directory in the TinyAra configuration file.
2. You can provide the path to the application directory on the command line
   like: make APPDIR=<path> or make CONFIG_APPS_DIR=<path>
3. When you configure TinyAra using tools/configure.sh, you can provide that path to the application directory on the configuration command line
   like: ./configure.sh -a <app-dir> <board-name>/<config-name>

Application Configuration File

The TinyAra configuration uses kconfig-frontends tools and the TinyAra configuration file (.config) file. For example, the TinyAra .config may have:

CONFIG_EXAMPLES_HELLO=y

This will select the apps/examples/hello in the following way:

• The top-level make will include examples/Make.defs
• examples/Make.defs will set CONFIGURED_APPS += examples/hello
  like this:

ifeq ($(CONFIG_EXAMPLES_HELLO),y)  
CONFIGURED_APPS += examples/hello  
endif

Suggestion for optimizing SmartFs Ops

Using just any buffer size for reading/appending to the contents of a SmartFs file in a back-to-back(looped) manner might cause repetitive reading of sectors and performance degradation. Hence, programmers are encouraged to use an optimal buffer size for reading/appending back-to-back to/from a SmartFs file.

You can use the following to obtain the optimal buffer size: -

stat("\mnt", &st);
buf_size = st.st_blksize;

Please refer to the "buffer_optimization" example (apps/examples/smartfs/buffer_optimization) for more details. The same will give you a demonstration of the improvement in read/append performance.

NOTE: This suggestion is useful only when read/append requests are made contiguously, back-to-back.