ARM: introduce sei() and cli().

No test, because it's tricky to test, but it compiles and the
firmware still works as before.

cpu.h

@@ -2,6 +2,40 @@
 #ifndef _CPU_H
 #define _CPU_H
 
+#if defined __AVR__
+
+  #include <avr/interrupt.h>
+
+#elif defined __ARMEL__
+
+  #include "cmsis-lpc11xx.h"  // For __ASM().
+
+  /** Enable interrupts.
+
+    This enables interrupts by clearing the I-bit in the CPSR.
+
+    Code copied from MBED, __enable_irq(), in file
+    mbed/libraries/mbed/targets/cmsis/core_cmFunc.h.
+  */
+  static void sei(void) __attribute__ ((always_inline));
+  inline void sei(void) {
+    __ASM volatile ("cpsie i" ::: "memory");
+  }
+
+  /** Disable interrupts.
+
+    This disables interrupts by setting the I-bit in the CPSR.
+
+    Code copied from MBED, __disable_irq(), in file
+    mbed/libraries/mbed/targets/cmsis/core_cmFunc.h.
+  */
+  static void cli(void) __attribute__ ((always_inline));
+  inline void cli(void) {
+    __ASM volatile ("cpsid i" ::: "memory");
+  }
+
+#endif /* __AVR__, __ARMEL__ */
+
 void cpu_init(void);
 
 #endif /* _CPU_H */

dda.c

@@ -7,14 +7,12 @@
 #include	<string.h>
 #include	<stdlib.h>
 #include	<math.h>
-#ifdef __AVR__
-#include	<avr/interrupt.h>
-#endif
 
 #include	"dda_maths.h"
 #include "preprocessor_math.h"
 #include "dda_kinematics.h"
 #include	"dda_lookahead.h"
+#include "cpu.h"
 #include	"timer.h"
 #include	"serial.h"
 #include	"sermsg.h"

dda_queue.c

@@ -5,9 +5,6 @@
 */
 
 #include	<string.h>
-#ifdef __AVR__
-#include	<avr/interrupt.h>
-#endif
 
 #include	"config_wrapper.h"
 #include	"timer.h"
@@ -17,6 +14,7 @@
 #include	"delay.h"
 #include	"sersendf.h"
 #include	"clock.h"
+#include "cpu.h"
 #include	"memory_barrier.h"
 
 /// movebuffer head pointer. Points to the last move in the queue.

gcode_process.c

@@ -5,12 +5,10 @@
 */
 
 #include	<string.h>
-#ifdef __AVR__
-#include	<avr/interrupt.h>
-#endif
 
 #include	"gcode_parse.h"
 
+#include "cpu.h"
 #include	"dda.h"
 #include	"dda_queue.h"
 #include	"watchdog.h"

intercom.c

@@ -4,15 +4,10 @@
 	\brief motherboard <-> extruder board protocol
 */
 
-#ifdef __AVR__
-#include	<avr/io.h>
-#include	<avr/interrupt.h>
-#endif
-#include	"memory_barrier.h"
-
 #include	"config_wrapper.h"
 #include "pinio.h"
 #include	"delay.h"
+#include "memory_barrier.h"
 
 #if	 (defined TEMP_INTERCOM) || (defined EXTRUDER)
 #define		INTERCOM_BAUD			57600

mendel.c

@@ -114,10 +114,12 @@ void init(void) {
   #ifdef SD
     sd_init();
   #endif
+  #endif /* __ARMEL_NOTYET__ */
 
 	// enable interrupts
 	sei();
 
+  #ifndef __ARMEL_NOTYET__
 	// reset watchdog
 	wd_reset();
   #endif /* __ARMEL_NOTYET__ */

timer.c

@@ -10,15 +10,13 @@
 	Teacup has tried numerous timer management methods, and this is the best so far.
 */
 
-#ifdef __AVR__
-#include	<avr/interrupt.h>
-#endif
-#include	"memory_barrier.h"
 
 #include	"arduino.h"
 #include	"config_wrapper.h"
 #include "pinio.h"
 #include "clock.h"
+#include "cpu.h"
+#include "memory_barrier.h"
 
 #ifdef	MOTHERBOARD
 #include	"dda_queue.h"