Sming (main)

This is the main Sming Component containing all architecture-independent code. All architecture-specific stuff is in either Sming (Esp8266) or Sming (Host).

Configuration variables

Serial Communications

COM_SPEED

Default baud rate for serial port.

This will recompile your application to use the revised baud rate. Note that this will change the default speed used for both flashing and serial comms. See also Esptool and Terminal for further details.

The default rate for serial ports is 115200 baud. You can change it like this:

make COM_SPEED=921600

Debug information log level and format

DEBUG_VERBOSE_LEVEL

When compiled in debug mode (:envvar:SMING_RELEASE undefined) there are four debug levels in increasing level of verbosity:

  • 0: errors

  • 1: warnings

  • 2: information (default)

  • 3: debug

Change it like this:

make DEBUG_VERBOSE_LEVEL=3
DEBUG_PRINT_FILENAME_AND_LINE

Set this to 1 to include the filename and line number in every line of debug output. This will require extra space on flash.

Note

If you change these settings and want them applied to Sming, not just your project, then you’ll need to recompile all components like this:

make components-clean
make DEBUG_VERBOSE_LEVEL=3
STRICT

  • default: undefined (standard warnings, treat as errors)

  • 1: Enable all warnings but do not treat as errors

By default, Sming builds code with a few warnings disabled:

  • sign-compare: Comparison between signed and unsigned values could produce an incorrect result when the signed value is converted to unsigned.

  • parentheses: Parentheses are omitted in certain contexts.

  • unused-variable: A local or static variable is unused aside from its declaration.

  • unused-but-set-variable: A local variable is assigned to, but otherwise unused.

  • strict-aliasing: Casts which can violate alignment rules.

These can be indicative of problematic code rather than errors. Because new compiler releases can increase the level of checking, this set may also need to change but it is kept minimal. See Sming/build.mk for the actual settings. See https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html for further details about all compiler settings. See also Clang Tools.

Any remaining warnings will be treated as errors and compilation will be halted.

It is a good idea to check your codebase with STRICT=1 which enables all warnings, plus a few additional ones such as unused-parameter.

When enabled, warnings are not treated as errors.

ENABLE_GDB
undefined (default)

Compile normally

1

Compile with debugging support.

In order to be able to debug live directly on the microcontroller you should re-compile your application with this setting enabled (set to 1).

This setting reduces optimisation levels and ensures full symbolic debugging information is available. However, because this affects the code produced it can mask some types of bug which only present in regular or release builds. For this reason, when ENABLE_GDB is changed only the application is recompiled automatically to ensure that the necessary GDB stub code is linked to enable communication with the debugger.

If you need to debug only a specific Component, rebuild just that component like this:

make ssl-clean
make ENABLE_GDB=1

The application code and ssl Component will now have debugging information, but everything else will remain unchanged. To rebuild the entire framework:

make clean components-clean
make ENABLE_GDB=1

Note also that gdb can always be used to examine the source disassembly without requiring connection to an actual device.

Build caching

ENABLE_CCACHE

Default: 0 (disabled)

Set to 1 to run (most) compilation through ccache. This speeds up re-compilation of code considerably at the expense of disk space and slightly extended initial compilation.

This setting was introduced mainly for CI builds as relatively little changes between runs.

ENABLE_SANITIZERS

default: 0 (off)

Enable this option to build with lots of runtime checking.

This provides some of the capabilities of valgrind but by instrumenting the code when it is compiled, rather than patching at runtime.

It also links in some additional runtime support libraries.

Run a full rebuild after changing this setting (or SANITIZERS):

make clean components-clean
make

Note

Applications cannot link when this setting is enabled as sanitizer runtime libraries are not currently available for embedded toolchains.

With Host builds using CLANG_BUILD, all runtime libraries should already be available. For GCC you will also need to install libasan and libubsan.

SANITIZERS

Selects which sanitizers are used. See ENABLE_SANITIZERS.

Release builds

SMING_RELEASE

By default, this value is undefined to produce a build with debug output. To build for release, do this:

make SMING_RELEASE=1

This remains in force until you change it back:

make SMING_RELEASE=

Localisation

LOCALE

Sming can format dates/time values based on a country code identified by this value. This is provided as a #define symbol for your application to use. See Sming/Core/SmingLocale.h for further details.

Networking

DISABLE_NETWORK

0 (Default) 1 - Remove core networking support

Applications which do not require networking can set this flag to avoid building or linking the core Networking Support library.

This will reduce build times, application size and RAM usage. Builds will not succeeded if network code has been inadvertently included.

DISABLE_WIFI

Note

EXPERIMENTAL

0 (Default) 1 - Exclude WiFi initialisation code

Keeps the core Networking Support library but excludes WiFi code. Applications using ethernet can use this to reduce code size. See Basic Ethernet.

Components

References

Environment Variables

SoC support