UEFI: https://uefi.org/specifications
ACPI: https://uefi.org/specifications
UEFI Platform Initialization Specification: https://uefi.org/specifications
SMBIOS: https://www.dmtf.org/standards/smbios
EDK2: https://github.com/tianocore/edk2

AMD64 Architecture Programmer’s Manual Volume 2: System Programming: https://developer.amd.com/resources/developer-guides-manuals/

Intel SDM: https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html

OSDEV Wiki: https://wiki.osdev.org/Main_Page

and, the OSDEV discord.
