Git-Mirrors/OpenModem
1
0
Fork 0
mirror of https://github.com/markqvist/OpenModem.git synced 2025-05-02 14:36:20 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Working

Browse source
This commit is contained in:
Mark Qvist 2014-04-03 22:21:37 +02:00
commit c898b090dd
1049 changed files with 288572 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

69
bertos/emul/switch_i386.S Normal file
View file

@ -0,0 +1,69 @@
/**
* \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 2004, 2008 Develer S.r.l. (http://www.develer.com/)
* Copyright 1999, 2000, 2001 Bernie Innocenti <bernie@codewiz.org>
* -->
*
* \author Bernie Innocenti <bernie@codewiz.org>
*
* \brief i386 context switch
*
* x86 function calling convention:
* --------------------------------
* arguments | callee-saved | extra caller-saved | return
* [callee-clobbered] | | [callee-clobbered] |
* -------------------------------------------------------------------------
* eax edx ecx | ebx edi esi ebp [*] | <none> | eax, edx
*
* [*] 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.
*/
#ifdef __APPLE__
// This workaround is necessary to compile under OS X assembler.
#define SWITCH_CONTEXT _asm_switch_context
#else
#define SWITCH_CONTEXT asm_switch_context
#endif
/* void asm_switch_context(void ** new_sp [sp+4], void ** save_sp [sp+8]) */
.globl SWITCH_CONTEXT
SWITCH_CONTEXT:
pushl %ebp
pushl %ecx
movl 0x10(%esp),%ebp /* ebp = save_sp */
movl %esp,(%ebp) /* *save_sp = esp */
movl 0x0c(%esp),%ebp /* ebp = new_sp */
movl (%ebp),%esp /* esp = *new_sp */
popl %ecx
popl %ebp
ret