diff options
Diffstat (limited to 'os/nil/ports/AVR/nilcore.c')
| -rw-r--r-- | os/nil/ports/AVR/nilcore.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/os/nil/ports/AVR/nilcore.c b/os/nil/ports/AVR/nilcore.c new file mode 100644 index 000000000..eb762b00b --- /dev/null +++ b/os/nil/ports/AVR/nilcore.c @@ -0,0 +1,138 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012,2013 Giovanni Di Sirio.
+
+ This file is part of ChibiOS/RT.
+
+ ChibiOS/RT is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ ChibiOS/RT is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file AVR/nilcore.c
+ * @brief AVR port code.
+ *
+ * @addtogroup AVR_CORE
+ * @{
+ */
+
+#include "nil.h"
+
+/*===========================================================================*/
+/* Module local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module exported variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Performs a context switch between two threads.
+ * @details This is the most critical code in any port, this function
+ * is responsible for the context switch between 2 threads.
+ * @note The implementation of this code affects <b>directly</b> the context
+ * switch performance so optimize here as much as you can.
+ * @note The function is declared as a weak symbol, it is possible to
+ * redefine it in your application code.
+ *
+ * @param[in] ntp the thread to be switched in
+ * @param[in] otp the thread to be switched out
+ */
+#if !defined(__DOXYGEN__)
+__attribute__((naked, weak))
+#endif
+void port_switch(Thread *ntp, Thread *otp) {
+
+ asm volatile ("push r2");
+ asm volatile ("push r3");
+ asm volatile ("push r4");
+ asm volatile ("push r5");
+ asm volatile ("push r6");
+ asm volatile ("push r7");
+ asm volatile ("push r8");
+ asm volatile ("push r9");
+ asm volatile ("push r10");
+ asm volatile ("push r11");
+ asm volatile ("push r12");
+ asm volatile ("push r13");
+ asm volatile ("push r14");
+ asm volatile ("push r15");
+ asm volatile ("push r16");
+ asm volatile ("push r17");
+ asm volatile ("push r28");
+ asm volatile ("push r29");
+
+ asm volatile ("movw r30, r22");
+ asm volatile ("in r0, 0x3d");
+ asm volatile ("std Z+5, r0");
+ asm volatile ("in r0, 0x3e");
+ asm volatile ("std Z+6, r0");
+
+ asm volatile ("movw r30, r24");
+ asm volatile ("ldd r0, Z+5");
+ asm volatile ("out 0x3d, r0");
+ asm volatile ("ldd r0, Z+6");
+ asm volatile ("out 0x3e, r0");
+
+ asm volatile ("pop r29");
+ asm volatile ("pop r28");
+ asm volatile ("pop r17");
+ asm volatile ("pop r16");
+ asm volatile ("pop r15");
+ asm volatile ("pop r14");
+ asm volatile ("pop r13");
+ asm volatile ("pop r12");
+ asm volatile ("pop r11");
+ asm volatile ("pop r10");
+ asm volatile ("pop r9");
+ asm volatile ("pop r8");
+ asm volatile ("pop r7");
+ asm volatile ("pop r6");
+ asm volatile ("pop r5");
+ asm volatile ("pop r4");
+ asm volatile ("pop r3");
+ asm volatile ("pop r2");
+ asm volatile ("ret");
+}
+
+/**
+ * @brief Start a thread by invoking its work function.
+ * @details If the work function returns @p chThdExit() is automatically
+ * invoked.
+ */
+void _port_thread_start(void) {
+
+ chSysUnlock();
+ asm volatile ("movw r24, r4");
+ asm volatile ("movw r30, r2");
+ asm volatile ("icall");
+ chSysHalt(0);
+}
+
+/** @} */
|