source: mainline/uspace/lib/c/arch/amd64/src/entryjmp.S

#
# Copyright (c) 2008 Jiri Svoboda
# 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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#include <abi/asmtool.h>

## void entry_point_jmp(void *entry_point, void *pcb);
#
# %rdi  contains entry_point
# %rsi  contains pcb
#
# Jump to program entry point
SYMBOL(entry_point_jmp)
        # use standard amd32 prologue not to confuse anybody
        push %rbp
        movq %rsp, %rbp

        # pcb must be passed in %rdi, use %rdx as a scratch register
        mov %rdi, %rdx
        mov %rsi, %rdi

        # jump to entry point
        jmp *%rdx