4034

Start implementing core x86 addressing mode decoding.

1 files changed, 10 insertions, 0 deletions

diff --git a/subx/000organization.cc b/subx/000organization.cc
index 320c0d4b..f729b17e 100644
--- a/subx/000organization.cc
+++ b/subx/000organization.cc
@@ -115,6 +115,7 @@ int main(int argc, char* argv[]) {
   // run on a 32-bit system
   assert(sizeof(int) == 4);
   assert(sizeof(float) == 4);
+  assert_little_endian();
 
   // End One-time Setup
 
@@ -138,3 +139,12 @@ int main(int argc, char* argv[]) {
 void reset() {
   // End Reset
 }
+
+void assert_little_endian() {
+  const int x = 1;
+  const char* y = reinterpret_cast<const char*>(&x);
+  if (*y != 1) {
+    cerr << "the SubX VM only runs on little-endian processors. Do you have Intel (or AMD or Atom) inside?\n";
+    exit(1);
+  }
+}