CM3: introduce asm_switch_context().

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3359 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/cpu/cortex-m3/hw/switch_ctx_cm3.S b/bertos/cpu/cortex-m3/hw/switch_ctx_cm3.S
new file mode 100644 (file)
index 0000000..bda6793
--- /dev/null
+++ b/bertos/cpu/cortex-m3/hw/switch_ctx_cm3.S
@@ -0,0 +1,54 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Cortex-M3 context switch
+ *
+ * \author Andrea Righi <arighi@develer.com>
+ */
+
+.syntax unified
+
+/* void asm_switch_context(void **new_sp [r0], void **save_sp [r1]) */
+.global asm_switch_context
+.thumb_func
+asm_switch_context:
+       mrs r12, msp
+        /* Save registers */
+       stmdb r12!, {r4-r11, lr}
+        /* Save old stack pointer */
+       str r12, [r1]
+        /* Load new stack pointer */
+       ldr r12, [r0]
+        /* Load new registers */
+       ldmia r12!, {r4-r11, lr}
+       msr msp, r12
+       bx lr