continue implementing paging

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86_64/src/exception_handling/assert.cpp b/arch/x86_64/src/exception_handling/assert.cpp
new file mode 100644
index 0000000..b55da49
--- /dev/null
+++ b/arch/x86_64/src/exception_handling/assert.cpp
@@ -0,0 +1,24 @@
+#include "arch/video/vga/text.hpp"
+
+namespace teachos::arch::exception_handling
+{
+  auto assert(bool condition, char const * message) -> void
+  {
+    if (condition)
+    {
+      return;
+    }
+
+    video::vga::text::write("Assert failed: ", video::vga::text::common_attributes::green_on_black);
+    video::vga::text::write(message, video::vga::text::common_attributes::green_on_black);
+    for (;;)
+    {
+      // Trick the compiler into thinking the variable is changes at run time,
+      // to prevent the while loop being optimized away
+      // See
+      // https://stackoverflow.com/questions/9495856/how-to-prevent-g-from-optimizing-out-a-loop-controlled-by-a-variable-that-can
+      // for more information.
+      asm volatile("" : "+g"(condition));
+    }
+  }
+}  // namespace teachos::arch::exception_handling
\ No newline at end of file