update readme to explain floating point printf configuration

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James Crosby 2016-02-01 14:12:12 +00:00
parent 3966fa750e
commit 2b8fd8872e
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@ -11,3 +11,28 @@ probably not succeed without target-specific startup code).
See [CHANGELOG.md](CHANGELOG.md) for the changes associated with
each version.
## Configuring floating point support in `printf`
Floating point support in `printf` is enabled by default by this target
description. (Although derived targets may override this behaviour through the
[yotta config](http://yottadocs.mbed.com/reference/config.html) system.)
If you need to change the default behaviour (perhaps because the increase in
code-size is unacceptable to you), then you can do this in the `config` section
of a target description, or in an application's `config.json` file:
```JSON
"gcc": {
"printf-float": false
}
```
Or:
```JSON
"gcc": {
"printf-float": true
}
```