From fb3438aac705534ddfb64e6adbf056511530301f Mon Sep 17 00:00:00 2001
From: Stephen Anthony <sa666666@gmail.com>
Date: Tue, 9 Jun 2020 12:32:14 -0230
Subject: [PATCH] Make sure 3E+ ROMs are always internally sized as a multiple
 1024 bytes.

---
 src/common/bspf.hxx    | 6 ++++++
 src/emucore/Cart3E.cxx | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/common/bspf.hxx b/src/common/bspf.hxx
index 24fe8d0a7..a887bf80a 100644
--- a/src/common/bspf.hxx
+++ b/src/common/bspf.hxx
@@ -140,6 +140,12 @@ namespace BSPF
     return power2;
   }
 
+  // Get next multiple of the given value
+  // Note that this only works when multiple is a power of two
+  inline size_t nextMultipleOf(size_t size, size_t multiple) {
+    return (size + multiple - 1) & ~(multiple - 1);
+  }
+
   // Make 2D-arrays using std::array less verbose
   template<typename T, size_t ROW, size_t COL>
   using array2D = std::array<std::array<T, COL>, ROW>;
diff --git a/src/emucore/Cart3E.cxx b/src/emucore/Cart3E.cxx
index 263c8b2e9..b03175477 100644
--- a/src/emucore/Cart3E.cxx
+++ b/src/emucore/Cart3E.cxx
@@ -22,7 +22,7 @@
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Cartridge3E::Cartridge3E(const ByteBuffer& image, size_t size,
                          const string& md5, const Settings& settings)
-  : CartridgeEnhanced(image, size, BSPF::nextPowerOfTwo(size), md5, settings)
+  : CartridgeEnhanced(image, size, BSPF::nextMultipleOf(size, 1_KB), md5, settings)
 {
   myBankShift = BANK_SHIFT;
   myRamSize = RAM_SIZE;