Geoff Chappell, Software Analyst
This page lists all the exports that were added to the HAL for version 6.2, i.e., for Windows 8. All five appear to be undocumented, but declarations for three of them were disclosed by Microsoft, possibly by oversight, in the 1511 edition of the Enterprise WDK for Windows 10.
Version 6.2 discontinues two functions. One, HalCallBios dates from version 5.2 (and only then in 64-bit builds). Another, HalMcUpdateReadPCIConfig, was anyway introduced only as recently as version 6.1.