scoutos / prex-0.9.0 / usr / arch / x86 / _crt0.S @ 03e9c04a
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/* |
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* Copyright (c) 2005, Kohsuke Ohtani |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the author nor the names of any co-contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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|
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/* |
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* crt0.S - C startup routine |
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*/ |
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|
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/** |
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* Stack layout: |
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* argc argument counter (integer) |
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* argv[0] program name (pointer) |
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* argv[1...N] program args (pointers) |
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* argv[argc-1] end of args (integer) |
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* NULL |
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* env[0...N] environment variables (pointers) |
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* NULL |
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*/ |
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|
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/* |
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* Entry point called by kernel first |
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*/ |
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.text |
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.global _start |
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_start: |
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popl %ecx /* Get argc */ |
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movl %esp, %ebx /* Get argv */ |
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movl %esp, %eax |
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movl %ecx, %edx |
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leal (%eax,%edx,4), %eax /* Get envp */ |
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|
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xorl %ebp, %ebp /* NULL */ |
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pushl %ebp /* Set return address */ |
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pushl %ebp |
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|
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pushl %eax /* Set envp */ |
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pushl %ebx /* Set argv */ |
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pushl %ecx /* Set argc */ |
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call __prex_main |
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