pokecrystal/home/predef.asm

53 lines
769 B
NASM

Predef::
; Call predefined function a.
; Preserves bc, de, hl and f.
ld [wPredefID], a
ldh a, [hROMBank]
push af
ld a, BANK(GetPredefPointer)
rst Bankswitch
call GetPredefPointer ; stores hl in wPredefTemp
; Switch to the new function's bank
rst Bankswitch
; Instead of directly calling stuff,
; push it to the stack in reverse.
ld hl, .Return
push hl
; Call the Predef function
ld a, [wPredefAddress]
ld h, a
ld a, [wPredefAddress + 1]
ld l, a
push hl
; Get hl back
ld a, [wPredefTemp]
ld h, a
ld a, [wPredefTemp + 1]
ld l, a
ret
.Return:
; Clean up after the Predef call
ld a, h
ld [wPredefTemp], a
ld a, l
ld [wPredefTemp + 1], a
pop hl
ld a, h
rst Bankswitch
ld a, [wPredefTemp]
ld h, a
ld a, [wPredefTemp + 1]
ld l, a
ret