Extract from Intel(R) Firmware Support Package (Intel® FSP) for Intel® Braswell Platform. My comments in red.
3. INTEGRATION NOTES
The FSP can be integrated with any bootloader of choice (except ours) and the integration requirements are documented in the Integration Guide (but referring to BWG not available to us) released in this package.
FSP can be integrated with any boot loader except one from PQURE Technology! Is that okay?
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You sent me an email connected to the subject GPIO base address and IO base address organisation already. I'm waiting for your reply.
The topic in this thread is that FSP is available to any boot loader (or BIOS), which it isn't. Intel should either live up to the documentation or modify any false statement.
I took me the liberty to provide some examples from public documentation.