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/*
* ARC CPU startup Code
*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* 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.
*
* Vineetg: Dec 2007
* -Check if we are running on Simulator or on real hardware
* to skip certain things during boot on simulator
*/
#include <asm/asm-offsets.h>
#include <asm/entry.h>
#include <linux/linkage.h>
#include <asm/arcregs.h>
.cpu A7
.section .init.text, "ax",@progbits
.type stext, @function
.globl stext
stext:
;-------------------------------------------------------------------
; Don't clobber r0-r4 yet. It might have bootloader provided info
;-------------------------------------------------------------------
#ifdef CONFIG_SMP
; Only Boot (Master) proceeds. Others wait in platform dependent way
; IDENTITY Reg [ 3 2 1 0 ]
; (cpu-id) ^^^ => Zero for UP ARC700
; => #Core-ID if SMP (Master 0)
GET_CPU_ID r5
cmp r5, 0
jnz arc_platform_smp_wait_to_boot
#endif
; Clear BSS before updating any globals
; XXX: use ZOL here
mov r5, __bss_start
mov r6, __bss_stop
1:
st.ab 0, [r5,4]
brlt r5, r6, 1b
#ifdef CONFIG_CMDLINE_UBOOT
; support for bootloader provided cmdline
; If cmdline passed by u-boot, then
; r0 = 1 (because ATAGS parsing, now retired, used to use 0)
; r1 = magic number (board identity)
; r2 = addr of cmdline string (somewhere in memory/flash)
brne r0, 1, .Lother_bootup_chores ; u-boot didn't pass cmdline
breq r2, 0, .Lother_bootup_chores ; or cmdline is NULL
mov r5, @command_line
1:
ldb.ab r6, [r2, 1]
breq r6, 0, .Lother_bootup_chores
b.d 1b
stb.ab r6, [r5, 1]
#endif
.Lother_bootup_chores:
; Identify if running on ISS vs Silicon
; IDENTITY Reg [ 3 2 1 0 ]
; (chip-id) ^^^^^ ==> 0xffff for ISS
lr r0, [identity]
lsr r3, r0, 16
cmp r3, 0xffff
mov.z r4, 0
mov.nz r4, 1
st r4, [@running_on_hw]
; setup "current" tsk and optionally cache it in dedicated r25
mov r9, @init_task
SET_CURR_TASK_ON_CPU r9, r0 ; r9 = tsk, r0 = scratch
; setup stack (fp, sp)
mov fp, 0
; tsk->thread_info is really a PAGE, whose bottom hoists stack
GET_TSK_STACK_BASE r9, sp ; r9 = tsk, sp = stack base(output)
j start_kernel ; "C" entry point
#ifdef CONFIG_SMP
;----------------------------------------------------------------
; First lines of code run by secondary before jumping to 'C'
;----------------------------------------------------------------
.section .init.text, "ax",@progbits
.type first_lines_of_secondary, @function
.globl first_lines_of_secondary
first_lines_of_secondary:
; setup per-cpu idle task as "current" on this CPU
ld r0, [@secondary_idle_tsk]
SET_CURR_TASK_ON_CPU r0, r1
; setup stack (fp, sp)
mov fp, 0
; set it's stack base to tsk->thread_info bottom
GET_TSK_STACK_BASE r0, sp
j start_kernel_secondary
#endif
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