73 lines
1.3 KiB
ArmAsm
73 lines
1.3 KiB
ArmAsm
/*
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* \brief Startup code for the Genode Kernel 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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/*
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* Copyright (C) 2011-2012 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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.section .text
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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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.rept 8
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nop
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.endr
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/* zero-fill BSS segment */
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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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sub r1, r1, #4
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1:
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str r2, [r0]
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add r0, r0, #4
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cmp r0, r1
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bne 1b
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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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/* jump to code that kernel has designated for when he has returned */
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ldr r1, =_call_after_kernel
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ldr r1, [r1]
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add pc, r1, #0
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/* handle for dynamic symbol objects */
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.align 3
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.global __dso_handle
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__dso_handle: .long 0
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.section .bss
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/* instruction pointer wich gets loaded when kernel returns */
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.align 3
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.global _call_after_kernel
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_call_after_kernel: .long 0
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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_utcb
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_main_utcb: .long 0
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