tree b4b689d97a9c8e7299e88e026591129267a379a1
parent c64b16c4bfd471219709ccabc55f090355edd62a
parent bbd847db4f404ab29f634b06df68ef0c42b91b09
author bors[bot] <26634292+bors[bot]@users.noreply.github.com> 1578740539 +0000
committer GitHub <noreply@github.com> 1578740539 +0000
gpgsig -----BEGIN PGP SIGNATURE-----
 
 wsBcBAABCAAQBQJeGas7CRBK7hj4Ov3rIwAAdHIIABORtUtC4G51kzm1HMkdmjHH
 RPdgZKfs31CQB9G4bK0FEv93xE4cmCSaJKia8yYn38/hdrI6PU8FCBdVjS6uYOwp
 HNGIMc2t9oufMPcxhXyvt4UM2rlcHfogewkI+bkrs9aDClr5hX3WjzmOWELSJugL
 P/fmB/Tz/QvtN8SVaZvU7NZuArX2wVm4Zw7XddYa6syL/Cy5dLz5MN1MbNmgUhcf
 ioC9H2mU0hrkSaB4VcCo0TkMWUMMd3dKebuKHga+v14kMLO+ed7E/aanlCEuvHQp
 yXqfQlY1kRXMg7A1CUjvRDCc7KPHkId016hhNjhtcckkj75HPa1iYiAqxo3qPVM=
 =g2p9
 -----END PGP SIGNATURE-----
 

Merge #122

122: Create 'drivers' singleton r=torfmaster a=torfmaster

# Overview
The drivers as well as the hardware represented by the drivers is only available once. To prevent hacing multiple mutable references to this global mutable state we do the following:

 * collect all drivers in a `drivers` object which is a singleton
 * ~if a driver allows to create a mutable reference to a part (e.g. an led) mutably borrow the driver as whole~

# Progress
The following drivers have been migrated:

[x] Timer
[x] Led
[x] Console
[x] GPIO
[x] Temperature 
[x] Buttons
[x] ADC
[x] RNG
[x] BLE
[x] ninedof

# Help needed
As this PR concerns API design comments are welcome! 
Moreover, the initialization of the `Hardware` struct is very verbose. However, initialization using a
`Default` implementation is not desired as this would make the individual drivers constructible outside the trate which is unsafe. Any ideas are very welcome. 

Co-authored-by: torfmaster <briefe@kebes.de>