Basic System Problem Analysis - August 2003

36
page 123/31/2003
Basic System Problem Analysis
PA-RISC General Registers
PA-RISC uses 32 general registers. The procedure calling
convention defines:
• R30 is “SP” or the stack pointer
• R27 is “DP” or the data pointer (global variables)
• R2 is “RP” or the procedure return pointer
• R28 and R29 are function return (ret0 and ret1)
• R26, R25, R24 and R23 can contain the first four
arguments passed to procedures (arg0..arg3)
• R31 is used as the “millicode RP”
• R0 is a read only register whose value is zero
Notes: