Merge #469: Specify a device support policy

6361a18 Specify a device support policy (Andrew Chow)

Pull request description:

  Specifies a policy for supporting a device as discussed in #382 (comment)

ACKs for top commit:
  instagibbs:
    utACK 6361a18
  Sjors:
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Tree-SHA512: dd5550617c63caf5450dcc3ccdab9425864c0f109f84c238c9be3c69f792ef5bb85193caad8affb530c324ecf1c59fdbeea888aed234378401ffd95bf9cf084c

docs/devices/index.rst

@@ -56,6 +56,34 @@ The table below lists what devices and features are supported for each device.
 | Display on device screen           | ✓             | ✓             | ✓          | ✓              | ―        | ✓        | ✓       | ✓        |
 +------------------------------------+---------------+---------------+------------+----------------+----------+----------+---------+----------+
 
+Support Policy
+================
+
+For a device to be supported by HWI, it must:
+
+* Use open source firmware as much as possible
+
+  * Entirely closed source devices will be rejected
+  * Devices may have closed source firmware components if required to under a NDA (e.g. a secure element with NDA)
+
+* Publicly documented communication protocol
+
+  * It is preferred to both document the protocol and provide a Python library for using it
+  * The library, with its own documentation, can suffice as "publicly documented"
+
+* Either (but preferably both):
+
+  * A simulator/emulator is available for automated tests to be run
+  * A promise to maintain and support from the vendor:
+
+Device support may be dropped:
+
+* If promised vendor maintenance and support disappears
+
+  * If there are continuous issues with the device and the vendor has failed to provide support and updates
+
+* If the device no longer receives security devices and there are known vulnerabilities and issues
+
 Device APIs
 ===========