diff --git a/source/arm11/open_agb_firm.c b/source/arm11/open_agb_firm.c
index 0b33212..a5cde89 100644
--- a/source/arm11/open_agb_firm.c
+++ b/source/arm11/open_agb_firm.c
@@ -144,19 +144,16 @@ Result dump_rom( u32 size )
 		return res;
 
 	u8 *p = ROM_LOC;
-	while( size > 0 )
+	u32 len;
+	for( u8 *p=ROM_LOC; size > 0; size-=len, p+=len )
 	{
-		u32 len;
-		res = fWrite( file, p, 512, &len );
+		res = fWrite( file, p, 256, &len );
 		if( res != RES_OK )
-			return res;
-		
-		size -= len;
-		p += len;
+			break;
 	}
 	fClose( file );
 
-	return RES_OK;
+	return size > 0 ? res : RES_OK;
 }
 #endif