b83ba0b9df
Selection of the DTB to be used was burried in more or less readable code in head.S. Move this code into a inline helper function and use it. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Florian Fainelli <f.fainelli@gmail.com>
155 lines
3.8 KiB
ArmAsm
155 lines
3.8 KiB
ArmAsm
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1994, 1995 Waldorf Electronics
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* Written by Ralf Baechle and Andreas Busse
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* Copyright (C) 1994 - 99, 2003, 06 Ralf Baechle
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* Copyright (C) 1996 Paul M. Antoine
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* Modified for DECStation and hence R3000 support by Paul M. Antoine
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* Further modifications by David S. Miller and Harald Koerfgen
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* Copyright (C) 1999 Silicon Graphics, Inc.
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* Kevin Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
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* Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
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*/
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#include <linux/init.h>
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#include <linux/threads.h>
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#include <asm/addrspace.h>
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#include <asm/asm.h>
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#include <asm/asmmacro.h>
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#include <asm/irqflags.h>
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#include <asm/regdef.h>
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#include <asm/mipsregs.h>
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#include <asm/stackframe.h>
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#include <kernel-entry-init.h>
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/*
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* For the moment disable interrupts, mark the kernel mode and
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* set ST0_KX so that the CPU does not spit fire when using
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* 64-bit addresses. A full initialization of the CPU's status
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* register is done later in per_cpu_trap_init().
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*/
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.macro setup_c0_status set clr
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.set push
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mfc0 t0, CP0_STATUS
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or t0, ST0_KERNEL_CUMASK|\set|0x1f|\clr
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xor t0, 0x1f|\clr
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mtc0 t0, CP0_STATUS
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.set noreorder
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sll zero,3 # ehb
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.set pop
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.endm
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.macro setup_c0_status_pri
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#ifdef CONFIG_64BIT
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setup_c0_status ST0_KX 0
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#else
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setup_c0_status 0 0
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#endif
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.endm
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.macro setup_c0_status_sec
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#ifdef CONFIG_64BIT
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setup_c0_status ST0_KX ST0_BEV
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#else
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setup_c0_status 0 ST0_BEV
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#endif
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.endm
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#ifndef CONFIG_NO_EXCEPT_FILL
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/*
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* Reserved space for exception handlers.
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* Necessary for machines which link their kernels at KSEG0.
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*/
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.fill 0x400
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#endif
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EXPORT(_stext)
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#ifdef CONFIG_BOOT_RAW
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/*
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* Give us a fighting chance of running if execution beings at the
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* kernel load address. This is needed because this platform does
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* not have a ELF loader yet.
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*/
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FEXPORT(__kernel_entry)
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j kernel_entry
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#endif /* CONFIG_BOOT_RAW */
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__REF
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NESTED(kernel_entry, 16, sp) # kernel entry point
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kernel_entry_setup # cpu specific setup
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setup_c0_status_pri
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/* We might not get launched at the address the kernel is linked to,
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so we jump there. */
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PTR_LA t0, 0f
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jr t0
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0:
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PTR_LA t0, __bss_start # clear .bss
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LONG_S zero, (t0)
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PTR_LA t1, __bss_stop - LONGSIZE
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1:
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PTR_ADDIU t0, LONGSIZE
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LONG_S zero, (t0)
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bne t0, t1, 1b
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LONG_S a0, fw_arg0 # firmware arguments
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LONG_S a1, fw_arg1
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LONG_S a2, fw_arg2
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LONG_S a3, fw_arg3
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MTC0 zero, CP0_CONTEXT # clear context register
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#ifdef CONFIG_64BIT
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MTC0 zero, CP0_XCONTEXT
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#endif
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PTR_LA $28, init_thread_union
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/* Set the SP after an empty pt_regs. */
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PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE
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PTR_ADDU sp, $28
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back_to_back_c0_hazard
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set_saved_sp sp, t0, t1
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PTR_SUBU sp, 4 * SZREG # init stack pointer
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#ifdef CONFIG_RELOCATABLE
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/* Copy kernel and apply the relocations */
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jal relocate_kernel
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/* Repoint the sp into the new kernel image */
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PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE
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PTR_ADDU sp, $28
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set_saved_sp sp, t0, t1
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PTR_SUBU sp, 4 * SZREG # init stack pointer
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/*
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* relocate_kernel returns the entry point either
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* in the relocated kernel or the original if for
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* some reason relocation failed - jump there now
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* with instruction hazard barrier because of the
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* newly sync'd icache.
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*/
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jr.hb v0
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#else /* !CONFIG_RELOCATABLE */
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j start_kernel
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#endif /* !CONFIG_RELOCATABLE */
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END(kernel_entry)
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#ifdef CONFIG_SMP
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/*
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* SMP slave cpus entry point. Board specific code for bootstrap calls this
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* function after setting up the stack and gp registers.
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*/
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NESTED(smp_bootstrap, 16, sp)
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smp_slave_setup
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setup_c0_status_sec
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j start_secondary
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END(smp_bootstrap)
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#endif /* CONFIG_SMP */
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