summaryrefslogtreecommitdiff
path: root/home/predef.asm
blob: 9c57497bf037f2549a0208b0d0f79e7ed6c2b19e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Predef:: ; 2d83
; Call predefined function a.
; Preserves bc, de, hl and f.

	ld [PredefID], a
	ld a, [hROMBank]
	push af

	ld a, BANK(GetPredefPointer)
	rst Bankswitch
	call GetPredefPointer ; stores hl in PredefTemp

; 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, [PredefAddress]
	ld h, a
	ld a, [PredefAddress + 1]
	ld l, a
	push hl

; Get hl back
	ld a, [PredefTemp]
	ld h, a
	ld a, [PredefTemp + 1]
	ld l, a
	ret

.Return
; Clean up after the Predef call

	ld a, h
	ld [PredefTemp], a
	ld a, l
	ld [PredefTemp+1], a

	pop hl
	ld a, h
	rst Bankswitch

	ld a, [PredefTemp]
	ld h, a
	ld a, [PredefTemp + 1]
	ld l, a
	ret
; 2dba