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1# Proprietary Vendor Libraries
2
3QMK Firmware cannot include support for any proprietary vendor libraries that impose additional restrictions beyond those in the GPL. This includes binary-only distributions, hardware-locked libraries, and code with redistribution limitations. This document explains why such libraries are incompatible with the GPL-based QMK Firmware and addresses commonly proposed workarounds.
4
5## Architecture Constraints
6
7Firmware presents unique licensing challenges:
8
9- **Monolithic binary**: All code compiles into a single executable image
10- **No OS isolation**: No operating system provides process or memory separation
11- **Shared resources**: All code shares the same memory space, peripherals, and execution context
12- **Static linking**: Everything is statically linked at compile time
13
14This monolithic nature means any proprietary code becomes inseparable from GPL code, creating immediate license violations.
15
16## Common Vendor Library Restrictions
17
18Proprietary vendor libraries typically impose restrictions incompatible with GPL freedoms:
19
20**Hardware Lock-in:**
21- Library only licensed for specific vendor's chips
22- Cannot port firmware to alternative hardware
23- Examples: Nordic's and ST's chip-only clauses in their respective licenses
24
25**No Source Distribution:**
26- Binary-only libraries without corresponding source
27- Precompiled static libraries (.a/.lib files)
28- No ability to modify or fix bugs
29- Examples: WCH CH582 precompiled libraries, Nordic SoftDevice
30
31**Redistribution Limitations:**
32- Restrictions on who can distribute
33- Limitations on commercial use
34- Required permissions or fees
35
36**Additional Legal Terms:**
37- Patent assertions beyond GPL's scope
38- Indemnification requirements
39- Jurisdiction restrictions
40- Explicit anti-GPL clauses
41
42## Bluetooth Stack Licensing Examples
43
44Both Nordic and ST provide Bluetooth stacks under restrictive licenses:
45
46**Nordic SoftDevice (under Nordic 5-clause license):**
47- Binary-only Bluetooth/radio stack
48- License restricts to Nordic hardware
49- No source code available
50- Communicates via SVC interface (still not GPL-compatible)
51
52**ST's Bluetooth Stack (under SLA0044 license):**
53- Explicitly forbids being subject to "Open Source Terms", specifically mentioning incompatibility with the GPL
54- Restricted to ST microcontrollers only
55- Similar functional role to Nordic's SoftDevice
56
57Both represent the same fundamental problem: critical wireless functionality locked behind proprietary licenses.
58
59## Why the System Library Exception Doesn't Apply
60
61The GPL's System Library exception **cannot** rescue proprietary vendor libraries.
62
63### System Library Requirements
64
65The exception only covers libraries that:
661. Are part of the "normal form of packaging a Major Component"
672. The Major Component is an OS kernel, compiler, or similar system software
683. Are not distributed with the application
694. Are not part of the application itself
70
71### Why Vendor Libraries Fail These Requirements
72
731. **No operating system**: Bare-metal firmware has no OS to provide system libraries
742. **Not Major Components**: Hardware drivers and HALs aren't kernels or compilers
753. **Distributed together**: Vendor code becomes part of the firmware binary
764. **Application-level code**: Peripheral drivers are application functionality
77
78The exception covers things like Windows system DLLs or Linux glibc, not microcontroller vendor libraries or Bluetooth stacks.
79
80## Attempted Workarounds
81
82### Architectural Separation Attempts
83
84**Supervisor Call (SVC) Interfaces:**
85
86Nordic's SoftDevice uses supervisor call based APIs instead of direct linking:
87- Fixed memory regions for proprietary code
88- Communication through CPU exception mechanisms
89- Claims of "no linking" between components
90
91**Why this fails:** The GPL considers functional integration, not just linking methods. In Bluetooth-capable boards, these would require the proprietary component to function, thus they form a single work regardless of the communication mechanism. This applies equally to Nordic's SoftDevice and any similar architecture ST provides.
92
93**Binary-Only Distributions:**
94
95Multiple vendors provide precompiled libraries:
96- WCH: Precompiled BLE stack
97- Nordic: Binary-only SoftDevice library
98- ST: Same solution as Nordic
99
100**Why this fails:** This is classic static linking of proprietary code into GPL code. The inability to modify these libraries violates GPL's fundamental requirements.
101
102### Loader-Based Separation
103
104- Write a GPL bootloader/loader
105- Load proprietary firmware (such as Nordic/ST Bluetooth) from external storage
106- Claim they're separate works
107
108**Problems:**
109- If designed as a system, courts view as single work
110- Distribution patterns matter (shipped together?)
111- Functional interdependence suggests unity
112- Appears designed to circumvent GPL
113
114## Real-World Examples
115
116### Bluetooth/Wireless Stacks
117- **Nordic SoftDevice**: Binary-only, SVC-interface, hardware-locked
118- **ST Bluetooth**: Binary-only, license explicitly GPL-incompatible
119- **WCH CH582**: Precompiled Bluetooth libraries
120
121### HAL and Driver Libraries
122- **ST HAL/LL drivers**: Source available but SLA0044 restricted
123- **Nordic SDK**: Source visible but 5-Clause restricted
124- **Various vendor HALs**: Platform-locked licenses
125
126### Mixed Proprietary/Open
127- Open peripheral drivers with closed protocol stacks
128- Basic HAL with proprietary performance libraries
129- Partially documented systems requiring binary supplements
130
131## Legal and Practical Consequences
132
133Including any proprietary vendor library means:
134
1351. **License Violation**: Immediate GPL non-compliance
1362. **Distribution Ban**: Users cannot legally share modified firmware
1373. **Commercial Risk**: Products using the firmware face legal liability
1384. **Contributor Tainting**: All GPL contributions become legally problematic
1395. **Update Restrictions**: Cannot fix bugs in proprietary components
140
141## Evaluation Criteria for Libraries
142
143Before including any library, QMK needs to verify:
144- Complete source code available
145- GPL-compatible license (GPL, LGPL, MIT, BSD, Apache)
146- No hardware restrictions
147- No redistribution limitations
148- No additional legal terms
149- No anti-GPL clauses
150
151## Policy Implementation
152
153QMK Firmware maintains a strict policy:
154
1551. **No proprietary libraries**: Regardless of technical workarounds
1562. **No binary blobs**: All code must have source available
1573. **No platform restrictions**: Must allow porting to any hardware
1584. **No additional terms**: Only GPL restrictions permitted
159
160## Summary
161
162There is no legally safe way to include proprietary vendor libraries in GPL firmware. This applies whether they're:
163- Bluetooth stacks (Nordic SoftDevice, ST Bluetooth)
164- Precompiled static libraries
165- Binary blobs with SVC interfaces
166- Source code with restrictive licenses
167- Mixed open/closed systems
168
169**Technical architectures cannot overcome license obligations.**
170
171QMK chooses GPL compliance, ensuring users receive all freedoms the GPL promises.