From Lazarus-ccr

The PowerPC uses the standard AIX or SysV calling conventions.

SysV calling conventions are described in

SYSTEM V APPLICATION BINARY INTERFACE
PowerPC Processor Supplement by
Steve Zucker, SunSoft
Kari Karhi, IBM

[edit] Methods

Self is passed in r3.

[edit] Nested functions

The parent frame pointer is passed in r3.