Added a memcpy function and a test.

* Alphabetized the functions.inc by label name.

Makefile

@@ -23,6 +23,7 @@ dirs:
 #
 cpu: cpuDirs \
 	${BIN_DIR}/cpu/callRet.gb \
+	${BIN_DIR}/cpu/memcpy.gb \
 	${BIN_DIR}/cpu/rst.gb
 
 cpuDirs:
@@ -34,6 +35,11 @@ ${BIN_DIR}/cpu/callRet.gb: dirs cpu/callRet.asm
 	${LD} -o ${BIN_DIR}/cpu/callRet.gb ${OBJ_DIR}/cpu/callRet.o
 	${FIX} ${BIN_DIR}/cpu/callRet.gb
 
+${BIN_DIR}/cpu/memcpy.gb: dirs cpu/memcpy.asm
+	${AS} -o ${OBJ_DIR}/cpu/memcpy.o cpu/memcpy.asm
+	${LD} -o ${BIN_DIR}/cpu/memcpy.gb ${OBJ_DIR}/cpu/memcpy.o
+	${FIX} ${BIN_DIR}/cpu/memcpy.gb
+
 ${BIN_DIR}/cpu/rst.gb: dirs cpu/rst.asm
 	${AS} -o ${OBJ_DIR}/cpu/rst.o cpu/rst.asm
 	${LD} -o ${BIN_DIR}/cpu/rst.gb ${OBJ_DIR}/cpu/rst.o

common/functions.inc

@@ -1,31 +1,4 @@
 SECTION "functions", ROM0[$2000]
-; Wait for vblank without using interrupts.
-waitVBlank:
-	push af
-.loop:
-	ldh a, [$ff44]
-	cp $90
-	jr nz, .loop
-	pop af
-	ret
-
-; Writes a value across 16 bytes, starting at HL. Intended to fill a single tile.
-; Parameters:
-;     B - The value to set the bytes to.
-; Modifies:
-;     HL - End result: HL + 16
-fillTile:
-	push af
-	push de
-	ld d, 16
-	ld a, b
-.loop:
-	ld [hli], a
-	dec d
-	jr nz, .loop
-	pop de
-	pop af
-	ret
 
 ; Clears the Nintendo logo tile data. This is intended to leave the screen open
 ; for simple (i.e. a bunch of boxes drawn with fillTile) test output.
@@ -61,3 +34,48 @@ clearLogo:
 	pop af
 	pop hl
 	ret
+
+; Writes a value across 16 bytes, starting at HL. Intended to fill a single tile.
+; Parameters:
+;     B - The value to set the bytes to.
+; Modifies:
+;     HL - End result: HL + 16
+fillTile:
+	push af
+	push de
+	ld d, 16
+	ld a, b
+.loop:
+	ld [hli], a
+	dec d
+	jr nz, .loop
+	pop de
+	pop af
+	ret
+
+; Copies up to 256 bytes of memory to another location.
+; Parameter:
+;     BC - Source location.
+;     HL - Destination location.
+;     D  - The number of bytes to copy.
+; Modifies:
+;     BC - End result: BC + D
+;     HL - End result: BC + d
+;     D  - End result: $00
+memcpy:
+	ld a, [bc]
+	ld [hli], a
+	inc bc
+	dec d
+	ret z
+	jr memcpy
+
+; Wait for vblank without using interrupts.
+waitVBlank:
+	push af
+.loop:
+	ldh a, [$ff44]
+	cp $90
+	jr nz, .loop
+	pop af
+	ret

cpu/memcpy.asm

@@ -0,0 +1,43 @@
+HeaderTitle EQUS "\"MEMCPY\""
+
+include "common/defines.inc"
+include "common/header.inc"
+include "common/functions.inc"
+
+; Output:
+;     1: copy block finished
+;     2: verify block succeeded
+
+SECTION "home", ROM0
+ProgramStart:
+	call clearLogo
+
+	ld hl, $c000  ; WRAM
+	ld bc, $0104  ; Cartridge Logo
+	ld d, 48  ; size
+	call memcpy
+
+	ld hl, $8010
+	call waitVBlank
+	ld b, $ff
+	call fillTile
+
+	ld hl, $c000
+	ld bc, $0104
+	ld d, 48
+.verifyLoop:
+	ld a, [bc]
+	cp [hl]
+	jr nz, loop
+	inc hl
+	inc bc
+	dec d
+	jr nz, .verifyLoop
+
+	ld hl, $8030
+	call waitVBlank
+	ld b, $ff
+	call fillTile
+
+loop:
+	jr loop