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/* DAG: Outdated, these have been combined !!!!!!!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