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CopyBytes::
; copy bc bytes from hl to de
inc b ; we bail the moment b hits 0, so include the last run
inc c ; same thing; include last byte
jr .HandleLoop
.CopyByte:
ld a, [hli]
ld [de], a
inc de
.HandleLoop:
dec c
jr nz, .CopyByte
dec b
jr nz, .CopyByte
ret
SwapBytes::
; swap bc bytes between hl and de
.Loop:
; stash [hl] away on the stack
ld a, [hl]
push af
; copy a byte from [de] to [hl]
ld a, [de]
ld [hli], a
; retrieve the previous value of [hl]; put it in [de]
pop af
ld [de], a
inc de
; handle loop stuff
dec bc
ld a, b
or c
jr nz, .Loop
ret
ByteFill::
; fill bc bytes with the value of a, starting at hl
inc b ; we bail the moment b hits 0, so include the last run
inc c ; same thing; include last byte
jr .HandleLoop
.PutByte:
ld [hli], a
.HandleLoop:
dec c
jr nz, .PutByte
dec b
jr nz, .PutByte
ret
GetFarByte::
; retrieve a single byte from a:hl, and return it in a.
; bankswitch to new bank
ldh [hTempBank], a
ldh a, [hROMBank]
push af
ldh a, [hTempBank]
rst Bankswitch
; get byte from new bank
ld a, [hl]
ldh [hFarByte], a
; bankswitch to previous bank
pop af
rst Bankswitch
; return retrieved value in a
ldh a, [hFarByte]
ret
GetFarWord::
; retrieve a word from a:hl, and return it in hl.
; bankswitch to new bank
ldh [hTempBank], a
ldh a, [hROMBank]
push af
ldh a, [hTempBank]
rst Bankswitch
; get word from new bank, put it in hl
ld a, [hli]
ld h, [hl]
ld l, a
; bankswitch to previous bank and return
pop af
rst Bankswitch
ret
FarCopyWRAM::
ldh [hTempBank], a
ldh a, [rSVBK]
push af
ldh a, [hTempBank]
ldh [rSVBK], a
call CopyBytes
pop af
ldh [rSVBK], a
ret
GetFarWRAMByte::
ldh [hTempBank], a
ldh a, [rSVBK]
push af
ldh a, [hTempBank]
ldh [rSVBK], a
ld a, [hl]
ldh [hFarByte], a
pop af
ldh [rSVBK], a
ldh a, [hFarByte]
ret
GetFarWRAMWord:: ; unreferenced
ldh [hTempBank], a
ldh a, [rSVBK]
push af
ldh a, [hTempBank]
ldh [rSVBK], a
ld a, [hli]
ld h, [hl]
ld l, a
pop af
ldh [rSVBK], a
ret
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