nmi: Don't try to switch onto extra stack in NMI handler

The NMI could occur when already on the extra stack, which would
corrupt it.  Always use the current stack on an NMI to avoid this.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
(cherry picked from commit 0c5a6077fc569d27aeadde690810f820b3256fbd)

diff --git a/src/romlayout.S b/src/romlayout.S
index fedadfe1c3f1755a35cdab083b9fa4fe9ebb9e4d..53cc0f5e3d45c51dc263757b08871309d8a0d1a0 100644 (file)
--- a/src/romlayout.S
+++ b/src/romlayout.S
@@ -548,7 +548,10 @@ entry_post:
         ENTRY_INTO32 _cfunc32flat_handle_post   // Normal entry point
 
         ORG 0xe2c3
-        IRQ_ENTRY 02
+        .global entry_02
+entry_02:
+        ENTRY handle_02  // NMI handler does not switch onto extra stack
+        iretw
 
         ORG 0xe3fe
         .global entry_13_official