From 4654d15e2aa22e979bfad11ca4a5565e351d7335 Mon Sep 17 00:00:00 2001
From: Matthew Berry <me@mattrb.com>
Date: Sun, 11 Oct 2020 19:44:31 -0700
Subject: [PATCH] arm fix strh, only store halfword

---
 src/crab/arm/halfword_data_transfer_imm.cr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/crab/arm/halfword_data_transfer_imm.cr b/src/crab/arm/halfword_data_transfer_imm.cr
index bdebf91..d94dead 100644
--- a/src/crab/arm/halfword_data_transfer_imm.cr
+++ b/src/crab/arm/halfword_data_transfer_imm.cr
@@ -27,7 +27,7 @@ module ARM
       if load
         @r[rd] = @gba.bus.read_half address
       else
-        @gba.bus[address] = @r[rd]
+        @gba.bus[address] = 0xFFFF_u16 & @r[rd]
       end
     when 0b10 # ldrsb
       @r[rd] = @gba.bus[address].to_i8!.to_u32