The MIT License (MIT)
Copyright © 2020 Gothel Software e.K.
Copyright © 2020 ZAFENA AB
Copyright © 2015-2016 Intel Corporation

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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Direct-BT License & Copyright
===============================
The MIT License (MIT) (see above)
Copyright © 2020 Gothel Software e.K.
Copyright © 2020 ZAFENA AB

Direct-BT imports certain information from Linux Kernel's BlueZ protocol stack,
originating from Qualcomm's sources under MIT license.
This information enables the use of certain kernel services via system calls.
Therefore, the license of this file has been aligned with this project's MIT license.
 
Related files are
- <api/direct_bt/BTIoctl.hpp>,
- <api/direct_bt/HCIIoctl.hpp> and 
- <api/direct_bt/L2CAPIoctl.hpp>.

Notice Qualcomm's original MIT license of the respective files.

Also notice Linus Torvalds's Linux Kernel license exception regarding kernel syscalls (ioctl):
<https://github.com/torvalds/linux/blob/master/LICENSES/exceptions/Linux-syscall-note>
and therefor <https://www.kernel.org/doc/html/v4.20/process/license-rules.html>.

<quote>
 NOTE! This copyright does *not* cover user programs that use kernel
 services by normal system calls - this is merely considered normal use
 of the kernel, and does *not* fall under the heading of "derived work".
</quote>
 
Given the syscall usage and original file's MIT license, 
we assume the following SPDX-License-Identifier should be declared: 
"SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) AND MIT"
 
...

This documentation of our usage is certainly better than GOOG's approach: 
<https://android.googlesource.com/platform/system/bluetooth/+/eclair-release/bluez-clean-headers/bluetooth?autodive=0/>,
which removes all authorship and origin.

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Copyright Intel Corporation 
============================
Direct-BT was initially developed as an 
alternative implementation to TinyB's Java API.

The latter was developed by the Intel Corporation
and licensed under the MIT license.
Main authors of TinyB were:
- Petre Eftime <petre.p.eftime@intel.com>
- Andrei Vasiliu <andrei.vasiliu@intel.com>

Today, TinyB has been removed from this project.

This copyright notice shall stay,
since some code fragments and portions of the infrastructure 
contains their work.

See also README.md: 'Direct-BT Origins'.