ref: 2ffbde764ec46d49e696df1f7d8b4b038638afad
dir: /home/copy2.asm/
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 [hBuffer], a ldh a, [hROMBank] push af ldh a, [hBuffer] rst Bankswitch ; get byte from new bank ld a, [hl] ldh [hBuffer], a ; bankswitch to previous bank pop af rst Bankswitch ; return retrieved value in a ldh a, [hBuffer] ret GetFarHalfword:: ; retrieve a halfword from a:hl, and return it in hl. ; bankswitch to new bank ldh [hBuffer], a ldh a, [hROMBank] push af ldh a, [hBuffer] rst Bankswitch ; get halfword 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 [hBuffer], a ldh a, [rSVBK] push af ldh a, [hBuffer] ldh [rSVBK], a call CopyBytes pop af ldh [rSVBK], a ret GetFarWRAMByte:: ldh [hBuffer], a ldh a, [rSVBK] push af ldh a, [hBuffer] ldh [rSVBK], a ld a, [hl] ldh [hBuffer], a pop af ldh [rSVBK], a ldh a, [hBuffer] ret GetFarWRAMWord:: ldh [hBuffer], a ldh a, [rSVBK] push af ldh a, [hBuffer] ldh [rSVBK], a ld a, [hli] ld h, [hl] ld l, a pop af ldh [rSVBK], a ret