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There is detailed information on the implementation and how this impacts errno specifically in the Wiki article: Userspace errno and TLS Thread Local Storage (TLS)
PR-957 PR-947 PR-963 PR-969 Provide nx_ versions of many functions that are used internally to avoid disrupting errno in userspace
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Changes to Build System
If you have are building NuttX for a custom board, you may need to make some of the following changes in build-related files for your board:
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