1 files changed, 113 insertions, 0 deletions
diff --git a/common/flag.asm b/common/flag.asm
new file mode 100644
index 000000000..e99248a3e
--- /dev/null
+++ b/common/flag.asm
@@ -0,0 +1,113 @@
+Function2e50: ; 2e50
+	xor a
+	ld hl, EventFlags
+	ld [hli], a
+	ret
+; 2e56
+
+Function2e56: ; 2e56
+	xor a
+	ld hl, BikeFlags
+	ld [hli], a
+	ld [hl], a
+	ret
+; 2e5d
+
+Function2e5d: ; 2e5d
+	ld a, [$d19a]
+	cp $2
+	jr z, .asm_2e69
+	cp $1
+	jr z, .asm_2e69
+	ret
+
+.asm_2e69
+	ld hl, StatusFlags
+	res 2, [hl]
+	ret
+; 2e6f
+
+
+EventFlagAction: ; 0x2e6f
+	ld hl, EventFlags
+	call FlagAction
+	ret
+
+FlagAction: ; 0x2e76
+; Perform action b on bit de in flag array hl.
+
+; inputs:
+; b: function
+;    0 clear bit
+;    1 set bit
+;    2 check bit
+; de: bit number
+; hl: index within bit table
+
+	; get index within the byte
+	ld a, e
+	and 7
+
+	; shift de right by three bits (get the index within memory)
+	srl d
+	rr e
+	srl d
+	rr e
+	srl d
+	rr e
+	add hl, de
+
+	; implement a decoder
+	ld c, 1
+	rrca
+	jr nc, .one
+	rlc c
+.one
+	rrca
+	jr nc, .two
+	rlc c
+	rlc c
+.two
+	rrca
+	jr nc, .three
+	swap c
+.three
+
+	; check b's value: 0, 1, 2
+	ld a, b
+	cp 1
+	jr c, .clearbit ; 0
+	jr z, .setbit ; 1
+
+	; check bit
+	ld a, [hl]
+	and c
+	ld c, a
+	ret
+
+.setbit
+	; set bit
+	ld a, [hl]
+	or c
+	ld [hl], a
+	ret
+
+.clearbit
+	; clear bit
+	ld a, c
+	cpl
+	and [hl]
+	ld [hl], a
+	ret
+; 0x2ead
+
+
+Function2ead: ; 2ead
+	ld de, ENGINE_POKEDEX
+	ld b, CHECK_FLAG
+	callba EngineFlagAction
+	ld a, c
+	and a
+	ret
+; 2ebb
+