HW_MFPR

0x19

Move From Processor Register — reads an IPR value into a general register. MFPR_* PAL calls are wrappers: write R0 with the IPR value read.

HW_MTPR

0x1D

Move To Processor Register — writes a general register value into an IPR. MTPR_* PAL calls are wrappers: read R16 as the value to write. Side effects include TLB invalidation, interrupt state updates, AST recalculation.

HW_LD

0x1B

Hardware Load — PAL-mode physical memory access bypassing normal VA→PA translation. Used by PAL code to read page table entries, HWPCB fields, and system data structures directly from physical memory.

HW_ST

0x1F

Hardware Store — PAL-mode physical memory write bypassing translation. Used by PAL code to update page table entries, HWPCB fields, and system control structures.

HW_REI

(within PAL)

Hardware Return from Exception/Interrupt — the sole legal exit from PAL mode. Restores context, deactivates shadow registers, flushes pipeline.