Added ARM7 ISRs notes to the documentation.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2137 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 16 insertions, 1 deletions

diff --git a/os/ports/GCC/ARM7/port.dox b/os/ports/GCC/ARM7/port.dox
index b70d230e7..afe419db7 100644
--- a/os/ports/GCC/ARM7/port.dox
+++ b/os/ports/GCC/ARM7/port.dox
@@ -115,7 +115,22 @@
  * have interrupt handlers compiled in thumb mode without have to use an

  * interworking mode (the mode switch is hidden in the macros), this

  * greatly improves code efficiency and size. You can look at the serial

- * driver for real examples of interrupt handlers.

+ * driver for real examples of interrupt handlers.<br>

+ * It is important that the serve_interrupt() interrupt function is not

+ * inlined by the compiler into the ISR or the code could still modify

+ * the unsaved registers, this can be accomplished using GCC by adding

+ * the attribute "noinline" to the function:

+ * @code

+ * #if defined(__GNU__)

+ * __attribute__((noinline))

+ * #endif

+ * static void serve_interrupt(void) {

+ * }

+ * @endcode

+ * Note that several commercial compilers support a GNU-like functions

+ * attribute mechanism.<br>

+ * Alternative ways are to use an appropriate #pragma directive or disable

+ * inlining optimizations in the modules containing the interrupt handlers.

  *

  * @ingroup gcc

  */