feat: add option to force-enable RTC

src/core/bus/GamePak.zig

@@ -6,6 +6,8 @@ const Bit = @import("bitfield").Bit;
 const Bitfield = @import("bitfield").Bitfield;
 const Backup = @import("backup.zig").Backup;
 const Allocator = std.mem.Allocator;
+
+const force_rtc = @import("../emu.zig").force_rtc;
 const log = std.log.scoped(.GamePak);
 
 const Self = @This();
@@ -23,7 +25,7 @@ pub fn init(allocator: Allocator, cpu: *Arm7tdmi, rom_path: []const u8, save_pat
     const file_buf = try file.readToEndAlloc(allocator, try file.getEndPos());
     const title = file_buf[0xA0..0xAC].*;
     const kind = Backup.guessKind(file_buf);
-    const device = guessDevice(file_buf);
+    const device = if (force_rtc) .Rtc else guessDevice(file_buf);
 
     logHeader(file_buf, &title);