114 lines
2.7 KiB
ArmAsm
114 lines
2.7 KiB
ArmAsm
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/*
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* linux/arch/arm26/kernel/head.S
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*
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* Copyright (C) 1994-2000 Russell King
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* Copyright (C) 2003 Ian Molton
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* 26-bit kernel startup code
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*/
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#include <linux/config.h>
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#include <linux/linkage.h>
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#include <asm/mach-types.h>
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.globl swapper_pg_dir
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.equ swapper_pg_dir, 0x0207d000
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/*
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* Entry point.
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*/
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.section ".init.text",#alloc,#execinstr
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ENTRY(stext)
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__entry:
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cmp pc, #0x02000000
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ldrlt pc, LC0 @ if 0x01800000, call at 0x02080000
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teq r0, #0 @ Check for old calling method
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blne oldparams @ Move page if old
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adr r0, LC0
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ldmib r0, {r2-r5, sp} @ Setup stack (and fetch other values)
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mov r0, #0 @ Clear BSS
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1: cmp r2, r3
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strcc r0, [r2], #4
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bcc 1b
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bl detect_proc_type
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str r0, [r4]
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bl detect_arch_type
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str r0, [r5]
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#ifdef CONFIG_XIP_KERNEL
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ldr r3, ETEXT @ data section copy
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ldr r4, SDATA
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ldr r5, EDATA
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1:
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ldr r6, [r3], #4
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str r6, [r4], #4
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cmp r4, r5
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blt 1b
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#endif
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mov fp, #0
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b start_kernel
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LC0: .word _stext
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.word __bss_start @ r2
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.word _end @ r3
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.word processor_id @ r4
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.word __machine_arch_type @ r5
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.word init_thread_union+8192 @ sp
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#ifdef CONFIG_XIP_KERNEL
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ETEXT: .word _endtext
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SDATA: .word _sdata
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EDATA: .word __bss_start
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#endif
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arm2_id: .long 0x41560200 @ ARM2 and 250 dont have a CPUID
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arm250_id: .long 0x41560250 @ So we create some after probing for them
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.align
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oldparams: mov r4, #0x02000000
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add r3, r4, #0x00080000
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add r4, r4, #0x0007c000
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1: ldmia r0!, {r5 - r12}
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stmia r4!, {r5 - r12}
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cmp r4, r3
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blt 1b
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mov pc, lr
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/*
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* We need some way to automatically detect the difference between
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* these two machines. Unfortunately, it is not possible to detect
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* the presence of the SuperIO chip, because that will hang the old
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* Archimedes machines solid.
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*/
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/* DAG: Outdated, these have been combined !!!!!!! */
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detect_arch_type:
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#if defined(CONFIG_ARCH_ARC)
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mov r0, #MACH_TYPE_ARCHIMEDES
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#elif defined(CONFIG_ARCH_A5K)
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mov r0, #MACH_TYPE_A5K
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#endif
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mov pc, lr
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detect_proc_type:
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mov ip, lr
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mov r2, #0xea000000 @ Point undef instr to continuation
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adr r0, continue - 12
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orr r0, r2, r0, lsr #2
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mov r1, #0
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str r0, [r1, #4]
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ldr r0, arm2_id
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swp r2, r2, [r1] @ check for swp (ARM2 cant)
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ldr r0, arm250_id
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mrc 15, 0, r3, c0, c0 @ check for CP#15 (ARM250 cant)
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mov r0, r3
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continue: mov r2, #0xeb000000 @ Make undef vector loop
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sub r2, r2, #2
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str r2, [r1, #4]
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mov pc, ip
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