From d4c2c3d2098616b3596b743f33fcc37629282ec0 Mon Sep 17 00:00:00 2001
From: Exzap <13877693+Exzap@users.noreply.github.com>
Date: Tue, 25 Jun 2024 15:50:06 +0200
Subject: [PATCH] nsyskbd: Stub KBDGetKey

Fixes MSX VC games freezing on boot
---
 src/Cafe/OS/libs/nsyskbd/nsyskbd.cpp | 35 ++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/src/Cafe/OS/libs/nsyskbd/nsyskbd.cpp b/src/Cafe/OS/libs/nsyskbd/nsyskbd.cpp
index 72cb9bd0..f1571cc0 100644
--- a/src/Cafe/OS/libs/nsyskbd/nsyskbd.cpp
+++ b/src/Cafe/OS/libs/nsyskbd/nsyskbd.cpp
@@ -3,6 +3,11 @@
 
 namespace nsyskbd
 {
+	bool IsValidChannel(uint32 channel)
+	{
+		return channel >= 0 && channel < 4;
+	}
+
 	uint32 KBDGetChannelStatus(uint32 channel, uint32be* status)
 	{
 		static bool loggedError = false;
@@ -16,8 +21,38 @@ namespace nsyskbd
 		return 0;
 	}
 
+#pragma pack(push, 1)
+	struct KeyState
+	{
+		uint8be channel;
+		uint8be ukn1;
+		uint8be _padding[2];
+		uint32be ukn4;
+		uint32be ukn8;
+		uint16be uknC;
+	};
+#pragma pack(pop)
+	static_assert(sizeof(KeyState) == 0xE); // actual size might be padded to 0x10?
+
+	uint32 KBDGetKey(uint32 channel, KeyState* keyState)
+	{
+		// used by MSX VC
+		if(!IsValidChannel(channel) || !keyState)
+		{
+			cemuLog_log(LogType::APIErrors, "KBDGetKey(): Invalid parameter");
+			return 0;
+		}
+		keyState->channel = channel;
+		keyState->ukn1 = 0;
+		keyState->ukn4 = 0;
+		keyState->ukn8 = 0;
+		keyState->uknC = 0;
+		return 0;
+	}
+
 	void nsyskbd_load()
 	{
 		cafeExportRegister("nsyskbd", KBDGetChannelStatus, LogType::Placeholder);
+		cafeExportRegister("nsyskbd", KBDGetKey, LogType::Placeholder);
 	}
 }