From ada691e704c0c8dcf4cb1aaeba5d76c02e89f03b Mon Sep 17 00:00:00 2001
From: Dave Hylands <dhylands@gmail.com>
Date: Sun, 28 Sep 2014 10:17:44 -0700
Subject: [PATCH] teensy: Enable 8-byte stack alignment for IRQ Handlers.

---
 teensy/main.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/teensy/main.c b/teensy/main.c
index 3b2994c86f..bc687fa675 100644
--- a/teensy/main.c
+++ b/teensy/main.c
@@ -253,9 +253,13 @@ char *strdup(const char *str) {
 #endif
 
 int main(void) {
-    pinMode(LED_BUILTIN, OUTPUT);
-    delay(1000);
+    // TODO: Put this in a more common initialization function.
+    // Turn on STKALIGN which keeps the stack 8-byte aligned for interrupts
+    // (per EABI)
+    #define SCB_CCR_STKALIGN (1 << 9)
+    SCB_CCR |= SCB_CCR_STKALIGN;
 
+    pinMode(LED_BUILTIN, OUTPUT);
     led_init();
 
 //    int first_soft_reset = true;