Identify link sync buffers, separate from link action bytes

3 files changed, 15 insertions, 10 deletions

diff --git a/engine/link/link.asm b/engine/link/link.asm
index 3dc46e50..c28330f4 100644
--- a/engine/link/link.asm
+++ b/engine/link/link.asm
@@ -2379,20 +2379,20 @@ Link_ResetSerialRegistersAfterLinkClosure:
 
 Link_EnsureSync:
 	add $d0
-	ld [wPlayerLinkAction], a
-	ld [wUnusedLinkAction], a
+	ld [wLinkPlayerSyncBuffer], a
+	ld [wLinkPlayerSyncBuffer + 1], a
 	ld a, $2
 	ldh [hVBlank], a
 	call DelayFrame
 	call DelayFrame
 .receive_loop
-	call Serial_ExchangeLinkMenuSelection
-	ld a, [wOtherPlayerLinkMode]
+	call Serial_ExchangeSyncBytes
+	ld a, [wLinkReceivedSyncBuffer]
 	ld b, a
 	and $f0
 	cp $d0
 	jr z, .done
-	ld a, [wOtherPlayerLinkAction]
+	ld a, [wLinkReceivedSyncBuffer + 1]
 	ld b, a
 	and $f0
 	cp $d0
diff --git a/home/serial.asm b/home/serial.asm
index 808111d5..47494a85 100644
--- a/home/serial.asm
+++ b/home/serial.asm
@@ -244,11 +244,10 @@ SerialDisconnected::
 	ld [wLinkTimeoutFrames + 1], a
 	ret
 
-; This is used to exchange the button press and selected menu item on the link menu.
-; The data is sent thrice and read twice to increase reliability.
-Serial_ExchangeLinkMenuSelection::
-	ld hl, wPlayerLinkAction
-	ld de, wOtherPlayerLinkMode
+; This is used to check that both players entered the same Cable Club room.
+Serial_ExchangeSyncBytes::
+	ld hl, wLinkPlayerSyncBuffer
+	ld de, wLinkReceivedSyncBuffer
 	ld c, 2
 	ld a, TRUE
 	ldh [hSerialIgnoringInitialData], a
diff --git a/wram.asm b/wram.asm
index 521e393f..1b382d39 100644
--- a/wram.asm
+++ b/wram.asm
@@ -1102,6 +1102,8 @@ wAttrmapEnd::
 
 wTileAnimBuffer:: ds 1 tiles
 
+; link data
+UNION
 wOtherPlayerLinkMode:: db
 wOtherPlayerLinkAction::
 wBattleAction:: db
@@ -1109,6 +1111,10 @@ wBattleAction:: db
 wPlayerLinkAction:: db
 wUnusedLinkAction:: db
 	ds 3
+NEXTU
+wLinkReceivedSyncBuffer:: ds 5
+wLinkPlayerSyncBuffer:: ds 5
+ENDU
 wLinkTimeoutFrames:: dw
 wLinkByteTimeout:: dw