[avr-libc-commit] [2319] Added experimental function ' void system_tick_i(void) '.

[Mike Rice]

Revision: 2319
          http://svn.sv.gnu.org/viewvc/?view=rev&root=avr-libc&revision=2319
Author:   swfltek
Date:     2013-03-31 21:05:09 +0000 (Sun, 31 Mar 2013)
Log Message:
-----------
Added experimental function ' void system_tick_i(void) '. This function should 
be suitable for call from a 'naked' ISR.

Modified Paths:
--------------
    trunk/avr-libc/devtools/Architecture.am
    trunk/avr-libc/include/time.h
    trunk/avr-libc/libc/time/Files.am

Added Paths:
-----------
    trunk/avr-libc/libc/time/system_tick_i.S

Modified: trunk/avr-libc/devtools/Architecture.am
===================================================================
--- trunk/avr-libc/devtools/Architecture.am     2013-03-30 11:59:28 UTC (rev 
2318)
+++ trunk/avr-libc/devtools/Architecture.am     2013-03-31 21:05:09 UTC (rev 
2319)
@@ -88,7 +88,8 @@
        $(stdio_a_asm_sources) \
        $(libm_a_c_sources) \
        $(libm_a_asm_sources) \
-       $(time_a_c_sources)
+       $(time_a_c_sources) \
+       $(time_a_asm_sources)
 
 nodist_libm_a_SOURCES = \
        $(libm_a_c_sources) \
@@ -106,4 +107,4 @@
 
 echo all distdir install installdirs clean distclean uninstall check:
 
-endif
\ No newline at end of file
+endif

Modified: trunk/avr-libc/include/time.h
===================================================================
--- trunk/avr-libc/include/time.h       2013-03-30 11:59:28 UTC (rev 2318)
+++ trunk/avr-libc/include/time.h       2013-03-31 21:05:09 UTC (rev 2319)
@@ -234,6 +234,18 @@
 */
 void system_tick(void);
 
+/**
+       This function increments the system clock, and must be called at a rate 
of one Hertz 
+       to maintain the system time. This function is safe to be called from a 
'naked' ISR...
+           
+           ISR(TIMER2_COMPA_vect, ISR_NAKED)
+           {
+               system_tick_i();
+               reti();
+           }
+*/
+void system_tick_i(void);
+
 enum _WEEK_DAYS_{
        SUNDAY,
        MONDAY,

Modified: trunk/avr-libc/libc/time/Files.am
===================================================================
--- trunk/avr-libc/libc/time/Files.am   2013-03-30 11:59:28 UTC (rev 2318)
+++ trunk/avr-libc/libc/time/Files.am   2013-03-31 21:05:09 UTC (rev 2319)
@@ -66,3 +66,6 @@
     utc_offset.c \
     week_of_month.c \
     week_of_year.c 
+
+time_a_asm_sources = \
+        system_tick_i.S

Added: trunk/avr-libc/libc/time/system_tick_i.S
===================================================================
--- trunk/avr-libc/libc/time/system_tick_i.S                            (rev 0)
+++ trunk/avr-libc/libc/time/system_tick_i.S    2013-03-31 21:05:09 UTC (rev 
2319)
@@ -0,0 +1,78 @@
+/*
+ * (c)2012 Michael Duane Rice All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer. Redistributions in binary
+ * form must reproduce the above copyright notice, this list of conditions
+ * and the following disclaimer in the documentation and/or other materials
+ * provided with the distribution. Neither the name of the copyright holders
+ * nor the names of contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* $Id$ */
+
+/*
+       Call this function at 1 Hz rate from a 'naked' ISR ( followed by reti ) 
to save a lot of 
+       stack activity.
+       
+        ISR(TIMER2_COMPA_vect, ISR_NAKED)
+        {
+            system_tick_i();
+            reti();
+        }
+*/
+
+__SREG__ = 0x3f
+__tmp_reg__ = 0
+__zero_reg__ = 1
+
+    .global    system_tick_i
+       .type   system_tick_i, @function
+system_tick_i:
+       push r1
+       push r0
+       in r0,__SREG__
+       push r0
+       clr __zero_reg__
+       push r24
+       push r25
+       push r26
+       push r27
+       lds r24,__system_time
+       lds r25,__system_time+1
+       lds r26,__system_time+2
+       lds r27,__system_time+3
+       adiw r24,1
+       adc r26,__zero_reg__
+       adc r27,__zero_reg__
+       sts __system_time,r24
+       sts __system_time+1,r25
+       sts __system_time+2,r26
+       sts __system_time+3,r27
+       pop r27
+       pop r26
+       pop r25
+       pop r24
+       pop r0
+       out __SREG__,r0
+       pop r0
+       pop r1
+       ret
+       .size   system_tick_i, .-system_tick_i