80 lines
1.7 KiB
ArmAsm
80 lines
1.7 KiB
ArmAsm
/**
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* \brief Startup code for Genode applications
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* \author Christian Helmuth
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* \author Martin Stein
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* \date 2009-08-12
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*/
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/*
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* Copyright (C) 2009-2013 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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/**************************
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** .text (program code) **
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**************************/
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.section ".text.crt0"
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/* program entry-point */
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.global _start
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_start:
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/* initialize GOT pointer in EBX */
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3:
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movl $., %ebx
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addl $_GLOBAL_OFFSET_TABLE_ + (. - 3b) , %ebx
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movl %esp, __initial_sp@GOTOFF(%ebx)
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/* make initial value of some registers available to higher-level code */
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mov %esp, __initial_sp
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mov %eax, __initial_ax
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mov %edi, __initial_di
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/*
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* Install initial temporary environment that is replaced later by the
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* environment that init_main_thread creates.
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*/
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leal _stack_high@GOTOFF(%ebx), %esp
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/* if this is the dynamic linker, init_rtld relocates the linker */
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call init_rtld
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/* create proper environment for the main thread */
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call init_main_thread
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/* apply environment that was created by init_main_thread */
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movl init_main_thread_result, %esp
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/* clear the base pointer in order that stack backtraces will work */
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xor %ebp, %ebp
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/* jump into init C code instead of calling it as it should never return */
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jmp _main
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/*********************************
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** .bss (non-initialized data) **
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*********************************/
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.bss
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/* stack of the temporary initial environment */
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.p2align 4
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.space 32 * 1024
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_stack_high:
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/* initial value of the ESP, EAX and EDI register */
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.global __initial_sp
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__initial_sp:
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.space 4
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.global __initial_ax
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__initial_ax:
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.space 4
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.global __initial_di
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__initial_di:
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.space 4
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