Vineet Gupta | c121c50 | 2013-01-18 15:12:20 +0530 | [diff] [blame] | 1 | /* |
| 2 | * ARC CPU startup Code |
| 3 | * |
| 4 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * Vineetg: Dec 2007 |
| 11 | * -Check if we are running on Simulator or on real hardware |
| 12 | * to skip certain things during boot on simulator |
| 13 | */ |
| 14 | |
| 15 | #include <asm/asm-offsets.h> |
| 16 | #include <asm/entry.h> |
| 17 | #include <linux/linkage.h> |
| 18 | #include <asm/arcregs.h> |
| 19 | |
| 20 | .cpu A7 |
| 21 | |
| 22 | .section .init.text, "ax",@progbits |
| 23 | .type stext, @function |
| 24 | .globl stext |
| 25 | stext: |
| 26 | ;------------------------------------------------------------------- |
| 27 | ; Don't clobber r0-r4 yet. It might have bootloader provided info |
| 28 | ;------------------------------------------------------------------- |
| 29 | |
Vineet Gupta | 05b016e | 2013-06-17 18:27:23 +0530 | [diff] [blame] | 30 | sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE] |
| 31 | |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 32 | #ifdef CONFIG_SMP |
| 33 | ; Only Boot (Master) proceeds. Others wait in platform dependent way |
| 34 | ; IDENTITY Reg [ 3 2 1 0 ] |
| 35 | ; (cpu-id) ^^^ => Zero for UP ARC700 |
| 36 | ; => #Core-ID if SMP (Master 0) |
Noam Camus | c3567f8 | 2013-09-12 13:07:39 +0530 | [diff] [blame^] | 37 | ; Note that non-boot CPUs might not land here if halt-on-reset and |
| 38 | ; instead breath life from @first_lines_of_secondary, but we still |
| 39 | ; need to make sure only boot cpu takes this path. |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 40 | GET_CPU_ID r5 |
| 41 | cmp r5, 0 |
| 42 | jnz arc_platform_smp_wait_to_boot |
| 43 | #endif |
Vineet Gupta | c121c50 | 2013-01-18 15:12:20 +0530 | [diff] [blame] | 44 | ; Clear BSS before updating any globals |
| 45 | ; XXX: use ZOL here |
| 46 | mov r5, __bss_start |
| 47 | mov r6, __bss_stop |
| 48 | 1: |
| 49 | st.ab 0, [r5,4] |
| 50 | brlt r5, r6, 1b |
| 51 | |
| 52 | #ifdef CONFIG_CMDLINE_UBOOT |
| 53 | ; support for bootloader provided cmdline |
| 54 | ; If cmdline passed by u-boot, then |
| 55 | ; r0 = 1 (because ATAGS parsing, now retired, used to use 0) |
| 56 | ; r1 = magic number (board identity) |
| 57 | ; r2 = addr of cmdline string (somewhere in memory/flash) |
| 58 | |
| 59 | brne r0, 1, .Lother_bootup_chores ; u-boot didn't pass cmdline |
| 60 | breq r2, 0, .Lother_bootup_chores ; or cmdline is NULL |
| 61 | |
| 62 | mov r5, @command_line |
| 63 | 1: |
| 64 | ldb.ab r6, [r2, 1] |
| 65 | breq r6, 0, .Lother_bootup_chores |
| 66 | b.d 1b |
| 67 | stb.ab r6, [r5, 1] |
| 68 | #endif |
| 69 | |
| 70 | .Lother_bootup_chores: |
| 71 | |
| 72 | ; Identify if running on ISS vs Silicon |
| 73 | ; IDENTITY Reg [ 3 2 1 0 ] |
| 74 | ; (chip-id) ^^^^^ ==> 0xffff for ISS |
| 75 | lr r0, [identity] |
| 76 | lsr r3, r0, 16 |
| 77 | cmp r3, 0xffff |
| 78 | mov.z r4, 0 |
| 79 | mov.nz r4, 1 |
| 80 | st r4, [@running_on_hw] |
| 81 | |
| 82 | ; setup "current" tsk and optionally cache it in dedicated r25 |
| 83 | mov r9, @init_task |
| 84 | SET_CURR_TASK_ON_CPU r9, r0 ; r9 = tsk, r0 = scratch |
| 85 | |
| 86 | ; setup stack (fp, sp) |
| 87 | mov fp, 0 |
| 88 | |
| 89 | ; tsk->thread_info is really a PAGE, whose bottom hoists stack |
| 90 | GET_TSK_STACK_BASE r9, sp ; r9 = tsk, sp = stack base(output) |
| 91 | |
| 92 | j start_kernel ; "C" entry point |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 93 | |
| 94 | #ifdef CONFIG_SMP |
| 95 | ;---------------------------------------------------------------- |
| 96 | ; First lines of code run by secondary before jumping to 'C' |
| 97 | ;---------------------------------------------------------------- |
| 98 | .section .init.text, "ax",@progbits |
| 99 | .type first_lines_of_secondary, @function |
| 100 | .globl first_lines_of_secondary |
| 101 | |
| 102 | first_lines_of_secondary: |
| 103 | |
Noam Camus | c3567f8 | 2013-09-12 13:07:39 +0530 | [diff] [blame^] | 104 | sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE] |
| 105 | |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 106 | ; setup per-cpu idle task as "current" on this CPU |
| 107 | ld r0, [@secondary_idle_tsk] |
| 108 | SET_CURR_TASK_ON_CPU r0, r1 |
| 109 | |
| 110 | ; setup stack (fp, sp) |
| 111 | mov fp, 0 |
| 112 | |
| 113 | ; set it's stack base to tsk->thread_info bottom |
| 114 | GET_TSK_STACK_BASE r0, sp |
| 115 | |
| 116 | j start_kernel_secondary |
| 117 | |
| 118 | #endif |