| /* |
| * 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 |
| ;------------------------------------------------------------------- |
| |
| ; 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 |
