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#
# Copyright (c) 2007 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.text

/** Syscall wrapper.
 *
 * Mind the order of arguments. First two arguments and the syscall number go to
 * scratch registers. An optimized version of this wrapper for fewer arguments
 * could benefit from this and not save unused registers on the stack.
 */
.global __syscall
__syscall:
    pushl %ebx
    pushl %esi
    pushl %edi
    pushl %ebp
    movl 20(%esp), %edx # First argument.
    movl 24(%esp), %ecx # Second argument.
    movl 28(%esp), %ebx # Third argument.
    movl 32(%esp), %esi # Fourth argument.
    movl 36(%esp), %edi # Fifth argument.
    movl 40(%esp), %ebp # Sixth argument.
    movl 44(%esp), %eax # Syscall number.
    int $0x30
    popl %ebp
    popl %edi
    popl %esi
    popl %ebx
    ret