76 lines
1.4 KiB
ArmAsm
76 lines
1.4 KiB
ArmAsm
/*
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* \brief Startup code for core on ARM
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* \author Martin Stein
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* \author Stefan Kalkowski
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* \date 2011-10-01
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*
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* The code in this file is compliant to the general ARM instruction- and
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* register-set but the semantics are tested only on ARMv6 and ARMv7 by now.
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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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/**
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* Do no operation for 'count' cycles
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*/
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.macro _nop count
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.rept \count
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mov r8, r8
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.endr
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.endm
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.section ".text.crt0"
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/* ELF entry symbol */
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.global _start
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_start:
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/* idle a little initially because 'u-boot' likes it this way */
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_nop 8
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/* zero-fill BSS segment, BSS boundaries must be aligned to 4 */
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.extern _bss_start
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.extern _bss_end
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ldr r0, =_bss_start
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ldr r1, =_bss_end
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mov r2, #0
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1:
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cmp r1, r0
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ble 2f
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str r2, [r0]
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add r0, r0, #4
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b 1b
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2:
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/* enable C++ to prepare the first kernel run */
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ldr sp, =_kernel_stack_high
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bl init_phys_kernel
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/* call kernel routine */
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.extern kernel
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_start_kernel:
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ldr sp, =_kernel_stack_high
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bl kernel
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/* catch erroneous kernel return */
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3: b 3b
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.section .bss
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/* kernel stack */
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.align 3
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.space 64*1024
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.global _kernel_stack_high
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_kernel_stack_high:
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/* main-thread UTCB-pointer for the Genode thread-API */
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.align 3
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.global _main_thread_utcb
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_main_thread_utcb: .long 0
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