Alternate preemption mode added to IAR port too.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@3016 35acf78f-673a-0410-8e92-d51de3d6d3f4

demos/ARMCM0-LPC1114-LPCXPRESSO/iar/ch.ewp

@@ -523,6 +523,7 @@
         </option>
         <option>
           <name>AUserIncludes</name>
+          <state>$PROJ_DIR$\..\</state>
           <state>$PROJ_DIR$\..\..\..\os\ports\IAR\ARMCMx\LPC11xx</state>
           <state>$PROJ_DIR$\..\..\..\boards\EA_LPCXPRESSO_BB_1114</state>
         </option>
@@ -1387,6 +1388,7 @@
         </option>
         <option>
           <name>AUserIncludes</name>
+          <state>$PROJ_DIR$\..\</state>
           <state>$PROJ_DIR$\..\..\..\os\ports\IAR\ARMCMx\LPC11xx</state>
           <state>$PROJ_DIR$\..\..\..\boards\EA_LPCXPRESSO_BB_1114</state>
         </option>

os/ports/IAR/ARMCMx/chcore_v6m.h

@@ -45,6 +45,15 @@
 /* Port configurable parameters.                                             */
 /*===========================================================================*/
 
+/**
+ * @brief   Alternate preemption method.
+ * @details Activating this option will make the Kernel use the PendSV
+ *          handler for preemption instead of the NMI handler.
+ */
+#ifndef CORTEX_ALTERNATE_SWITCH
+#define CORTEX_ALTERNATE_SWITCH         FALSE
+#endif
+
 /*===========================================================================*/
 /* Port derived parameters.                                                  */
 /*===========================================================================*/
@@ -72,6 +81,15 @@
 #define CH_CORE_VARIANT_NAME            "Cortex-M1"
 #endif
 
+/**
+ * @brief   Port-specific information string.
+ */
+#if !CORTEX_ALTERNATE_SWITCH || defined(__DOXYGEN__)
+#define CH_PORT_INFO                    "Preemption through NMI"
+#else
+#define CH_PORT_INFO                    "Preemption through PendSV"
+#endif
+
 /*===========================================================================*/
 /* Port implementation part.                                                 */
 /*===========================================================================*/

os/ports/IAR/ARMCMx/chcoreasm_v6m.s

@@ -24,12 +24,11 @@
         PRESERVE8
 
 /*
- * Imports the Cortex-Mx parameters header and performs the same calculations
- * done in chcore.h.
+ * Imports the Cortex-Mx configuration headers.
  */
-#include "cmparams.h"
-
-#define CORTEX_PRIORITY_MASK(n) ((n) << (8 - CORTEX_PRIORITY_BITS))
+#define _FROM_ASM_
+#include "chconf.h"
+#include "chcore.h"
 
 EXTCTX_SIZE     SET     32
 CONTEXT_OFFSET  SET     12
@@ -81,6 +80,7 @@ _port_thread_start:
  * The NMI vector is used for exception mode re-entering after a context
  * switch.
  */
+#if !CORTEX_ALTERNATE_SWITCH
         PUBLIC  NMIVector
 NMIVector:
         mrs     r3, PSP
@@ -88,6 +88,21 @@ NMIVector:
         msr     PSP, r3
         cpsie   i
         bx      lr
+#endif
+
+/*
+ * PendSV vector.
+ * The PendSV vector is used for exception mode re-entering after a context
+ * switch.
+ */
+#if CORTEX_ALTERNATE_SWITCH
+        PUBLIC  PendSVVector
+PendSVVector:
+        mrs     r3, PSP
+        adds    r3, r3, #32
+        msr     PSP, r3
+        bx      lr
+#endif
 
 /*
  * Post-IRQ switch code.
@@ -96,12 +111,18 @@ NMIVector:
         PUBLIC  _port_switch_from_isr
 _port_switch_from_isr:
         bl      chSchDoRescheduleI
-        movs    r3, #128
-        lsls    r3, r3, #24
         ldr     r2, =SCB_ICSR
+        movs    r3, #128
+#if CORTEX_ALTERNATE_SWITCH
+        lsls    r3, r3, #21
         str     r3, [r2, #0]
-_waitnmi:
-        b       _waitnmi
+        cpsie   i
+#else
+        lsls    r3, r3, #24
+        str     r3, [r2, #0]
+#endif
+waithere:
+        b       waithere
 
 /*
  * Reschedule verification and setup after an IRQ.

os/ports/RVCT/ARMCMx/chcoreasm_v6m.s

@@ -89,8 +89,8 @@ NMIVector       PROC
 #endif
 
 /*
- * NMI vector.
- * The NMI vector is used for exception mode re-entering after a context
+ * PendSV vector.
+ * The PendSV vector is used for exception mode re-entering after a context
  * switch.
  */
 #if CORTEX_ALTERNATE_SWITCH