51 lines
1.4 KiB
C
51 lines
1.4 KiB
C
/*
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* \brief Call main function (X86 specific)
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* \author Sebastian Sumpf <Sebastian.Sumpf@genode-labs.com>
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* \author Martin Stein
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* \date 2011-05-02
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*/
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/*
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* Copyright (C) 2011-2013 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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#ifndef _X86_32__CALL_MAIN_H_
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#define _X86_32__CALL_MAIN_H_
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void * my_stack_top();
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void set_program_var(const char *, const void *);
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extern void * __initial_sp;
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extern void * __initial_ax;
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extern void * __initial_di;
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/**
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* Call program _main with the environment that its CRT0 would have created
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*
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* \param _main_fp pointer to _main function of dynamic program
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*/
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void call_main(void (*_main_fp)(void))
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{
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/* make initial value of some registers available to dynamic program */
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set_program_var("__initial_sp", __initial_sp);
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set_program_var("__initial_ax", __initial_ax);
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set_program_var("__initial_di", __initial_di);
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/*
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* We could also do a call but that would enable the the program main to
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* return to LDSO wich isn't desired. This means also that not resetting
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* the SP to stack top as we do would waste stack memory for dead LDSO
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* frames.
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*/
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asm volatile ("mov %[sp], %%esp;"
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"xor %%ebp, %%ebp;"
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"jmp *%[ip];"
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:: [sp] "r" (my_stack_top()),
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[ip] "r" (_main_fp)
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: "memory");
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}
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#endif /* _X86_32__CALL_MAIN_H_ */
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