-/*!
+/**
* \file
* <!--
- * Copyright 2004 Develer S.r.l. (http://www.develer.com/)
- * Copyright 1999,2000,2001 Bernie Innocenti <bernie@codewiz.org>
- * This file is part of DevLib - See devlib/README for information.
- * -->
+ * This file is part of BeRTOS.
*
- * \brief i386 context switch
+ * 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.
*
- * \version $Id$
+ * 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.
*
- * \author Bernie Innocenti <bernie@codewiz.org>
- */
-
-/*
- * $Log$
- * Revision 1.4 2006/09/20 14:02:49 marco
- * C-style comment.
+ * 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
*
- * Revision 1.3 2006/02/24 01:35:40 bernie
- * Update for new emulator.
+ * 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.
*
- * Revision 1.2 2006/02/24 01:17:05 bernie
- * Update for new emulator.
+ * Copyright 2004, 2008 Develer S.r.l. (http://www.develer.com/)
+ * Copyright 1999, 2000, 2001 Bernie Innocenti <bernie@codewiz.org>
+ * -->
*
- * Revision 1.1 2005/11/27 03:06:15 bernie
- * Add x86_64 task switching (to be updated to new-style scheduler).
+ * \author Bernie Innocenti <bernie@codewiz.org>
*
- * Revision 1.1 2005/11/14 21:06:38 bernie
- * Add x86_64 support.
+ * \brief x86_64 context switch
*
- * Revision 1.2 2004/06/06 16:14:12 bernie
- * Add DevLib license information.
+ * x86_64 function call convention:
+ * --------------------------------
+ * arguments | callee-saved | extra caller-saved | return
+ * [callee-clobbered] | | [callee-clobbered] |
+ * -------------------------------------------------------------------------
+ * rdi rsi rdx rcx r8-9 | rbx rbp [*] r12-15 | r10-11 | rax, rdx
*
- * Revision 1.1 2004/05/23 17:27:00 bernie
- * Import kern/ subdirectory.
+ * [*] In the frame-pointers case rbp must hold a base address for the
+ * current stack frame.
*
+ * asm_switch_context() can be considered as a normal function call, so we need
+ * to save all the callee-clobbered registers minus the return registers.
*/
-/* I know it's ugly... */
-/* .intel_syntax */
-
-/* void AsmSwitchContext(void **new_sp, void **save_sp) */
-/* %rdi %rsi */
+/* void asm_switch_context(void **new_sp [%rdi], void **save_sp [%rsi]) */
.globl asm_switch_context
asm_switch_context:
- pushq %rax
- pushq %rbx
- pushq %rcx
- pushq %rdx
- pushq %rsi
- pushq %rdi
pushq %rbp
+ pushq %rdi
+ pushq %rsi
+ pushq %rcx
+ pushq %r8
+ pushq %r9
+ pushq %r10
+ pushq %r11
movq %rsp,(%rsi) /* *save_sp = rsp */
movq (%rdi),%rsp /* rsp = *new_sp */
- popq %rbp
- popq %rdi
- popq %rsi
- popq %rdx
+ popq %r11
+ popq %r10
+ popq %r9
+ popq %r8
popq %rcx
- popq %rbx
- popq %rax
- ret
-
-/* int asm_switch_version(void) */
-.globl asm_switch_version
-asm_switch_version:
- mov $1,%rax
+ popq %rsi
+ popq %rdi
+ popq %rbp
ret
-