1 files changed, 49 insertions, 0 deletions
diff --git a/cpukit/score/cpu/arm/armv7m-context-switch.c b/cpukit/score/cpu/arm/armv7m-context-switch.c
new file mode 100644
index 0000000000..bb73c6671a
--- /dev/null
+++ b/cpukit/score/cpu/arm/armv7m-context-switch.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2011 Sebastian Huber.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/percpu.h>
+
+#ifdef ARM_MULTILIB_ARCH_V7M
+
+#include <rtems/score/armv7m.h>
+
+void __attribute__((naked)) _CPU_Context_switch(
+  Context_Control *executing,
+  Context_Control *heir
+)
+{
+  __asm__ volatile (
+    "movw r2, #:lower16:_Per_CPU_Information\n"
+    "movt r2, #:upper16:_Per_CPU_Information\n"
+    "ldr r3, [r2, %[isrpcpuoff]]\n"
+    "stm r0, {r4-r11, lr}\n"
+    "str sp, [r0, %[spctxoff]]\n"
+    "str r3, [r0, %[isrctxoff]]\n"
+    "ldr r3, [r1, %[isrctxoff]]\n"
+    "ldr sp, [r1, %[spctxoff]]\n"
+    "ldm r1, {r4-r11, lr}\n"
+    "str r3, [r2, %[isrpcpuoff]]\n"
+    "bx lr\n"
+    :
+    : [spctxoff] "J" (offsetof(Context_Control, register_sp)),
+      [isrctxoff] "J" (offsetof(Context_Control, isr_nest_level)),
+      [isrpcpuoff] "J" (offsetof(Per_CPU_Control, isr_nest_level))
+  );
+}
+
+#endif /* ARM_MULTILIB_ARCH_V7M */