The init code for the Z180 is just 3 simple commands:

        LD	A,	00000000b      ; Turn off Z180 Refresh cycles.
        OUT0	(36H),	A
        LD	A,	11110000b      ; Maximum wait states for Memory and I/O.
        OUT0	(32H),	A
        LD	A,	01000000b      ; Reloc Z180 internal regs to 40H-7FH I/O addresses.
		OUT0	(3FH),	A           

The internal registers can be relocated to 4 I/O address blocks by loading A with other values:
        LD	A,	01000000b      ; Reloc Z180 internal regs to 40H-7FH
        LD	A,	10000000b      ; Reloc Z180 internal regs to 80H-BFH
        LD	A,	11000000b      ; Reloc Z180 internal regs to C0H-FFH
        LD	A,	00000000b      ; Reloc Z180 internal regs to 00H-3FH - default after reset