SPRESENSE is the code name of the product CXD5602 produced by Sony Semiconductor Solutions Corporation.
The CXD5602 is ARM powered SoC, including many peripherals for IoT and wearable solutions.

SPRESENSE SDK is based on NuttX. So please refer to original NuttX site to see basic kernel information.

This SDK is constructed by series of libraries, drivers and architecture specific code, and it will help you get started and create faster for your products.

Directory structure

sdk
|-- configs        - Pre-defined configuration files
|   |-- default    - Default configuration file
|   |-- device     - Device configuration files
|   |-- feature    - Feature configuration files
|   `-- examples   - Examples configuration files
|-- modules
|   |-- asmp           - ASMP framework
|   |-- audio          - Audio library
|   |-- bluetooth      - Bluetooth library
|   |-- digital_filter - Digital filter library
|   |-- dnnrt          - DNN Runtime library
|   |-- fwuputils      - Firmware update utility
|   |-- include        - Library headers
|   |-- mpcomm         - Multi processor communication framework
|   |-- sensing        - Smart sensing library
|   `-- tflmrt         - TensorFlow Lite for Microcontrollers Runtime library
|-- system         - System commands
`-- tools          - Build utilities

Build instruction

Please see Spresense SDK Getting Started Guide for more details.

$ tools/config.py default
$ make

Configuration

SDK provides tools/config.py as configuration frontend for SDK and NuttX kernel configuration. tools/config.py invokes kconfig tool so this must be installed prior it is used. tools/config.py must be called from top of SDK source tree.

e.g.

$ tools/config.py --list  (list SDK predefined configs)

The first time you run SDK setup, or if you want to change to predefined config, specify predefined <config name> as parameter:

$ tools/config.py <config name> [<config name>...]

You can specify multiple predefines, it allows combination of predefines.

e.g.

$ tools/config.py examples/audio_player examples/gnss

tools/config.py can be invoked menu style configuration UI by following options.

$ tools/config.py --menuconfig (same as 'make menuconfig')
$ tools/config.py --qconfig    (same as 'make qconfig')
$ tools/config.py --gconfig    (same as 'make gconfig')

Additionally, you can use menu invocation with predefined configs like this:

$ tools/config.py --menuconfig default

Save your configuration

If you want to save your edited options, then try tools/mkdefconfig.py. It is for saving user configuration as predefined config.

You can save current SDK configuration like this:

$ tools/mkdefconfig.py <config name>

After that, you can choose their saved default configs to specify tools/config.py's config name.

If your specified config name already exists, tools/mkdefconfig.py shows a confirm message to overwrite.

By default, tools/config.py and tools/mkdefconfig.py find out specified configurations under configs directory. You can change the default configuration file directory with -d or --dir option, both of tools/config.py and tools/mkdefconfig.py are supported.

If you want to save your customized configuration to where you want, type like this:

$ tools/mkdefconfig.py -d ../path/to/configs <config name>

When you want to use configurations in alternative directory:

$ tools/config.py -d ../path/to/configs <config name>

Build

Build the NuttX and SDK source code by following the above configuration.

$ make

To increase build speed, you can pass the -jN flag to make, where N is the number of parallel jobs to run simultaneously.

After built successfully, you can see nuttx and nuttx.spk files in top of SDK source tree.