1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
/*
* 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 <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
#include <asm/arcregs.h>
#include <asm/cache.h>
#include <asm/irqflags.h>
.macro CPU_EARLY_SETUP
; Setting up Vectror Table (in case exception happens in early boot
sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
; Disable I-cache/D-cache if kernel so configured
lr r5, [ARC_REG_IC_BCR]
breq r5, 0, 1f ; I$ doesn't exist
lr r5, [ARC_REG_IC_CTRL]
#ifdef CONFIG_ARC_HAS_ICACHE
bclr r5, r5, 0 ; 0 - Enable, 1 is Disable
#else
bset r5, r5, 0 ; I$ exists, but is not used
#endif
sr r5, [ARC_REG_IC_CTRL]
1:
lr r5, [ARC_REG_DC_BCR]
breq r5, 0, 1f ; D$ doesn't exist
lr r5, [ARC_REG_DC_CTRL]
bclr r5, r5, 6 ; Invalidate (discard w/o wback)
#ifdef CONFIG_ARC_HAS_DCACHE
bclr r5, r5, 0 ; Enable (+Inv)
#else
bset r5, r5, 0 ; Disable (+Inv)
#endif
sr r5, [ARC_REG_DC_CTRL]
1:
#ifdef CONFIG_ISA_ARCV2
; Unaligned access is disabled at reset, so re-enable early as
; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access
; by default
lr r5, [status32]
#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
bset r5, r5, STATUS_AD_BIT
#else
; Although disabled at reset, bootloader might have enabled it
bclr r5, r5, STATUS_AD_BIT
#endif
kflag r5
#endif
.endm
.section .init.text, "ax",@progbits
;----------------------------------------------------------------
; Default Reset Handler (jumped into from Reset vector)
; - Don't clobber r0,r1,r2 as they might have u-boot provided args
; - Platforms can override this weak version if needed
;----------------------------------------------------------------
WEAK(res_service)
j stext
END(res_service)
;----------------------------------------------------------------
; Kernel Entry point
;----------------------------------------------------------------
ENTRY(stext)
CPU_EARLY_SETUP
#ifdef CONFIG_SMP
GET_CPU_ID r5
cmp r5, 0
mov.nz r0, r5
bz .Lmaster_proceed
; Non-Masters wait for Master to boot enough and bring them up
; when they resume, tail-call to entry point
mov blink, @first_lines_of_secondary
j arc_platform_smp_wait_to_boot
.Lmaster_proceed:
#endif
; Clear BSS before updating any globals
; XXX: use ZOL here
mov r5, __bss_start
sub r6, __bss_stop, r5
lsr.f lp_count, r6, 2
lpnz 1f
st.ab 0, [r5, 4]
1:
; Uboot - kernel ABI
; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
; r1 = magic number (always zero as of now)
; r2 = pointer to uboot provided cmdline or external DTB in mem
; These are handled later in handle_uboot_args()
st r0, [@uboot_tag]
st r2, [@uboot_arg]
; 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
END(stext)
#ifdef CONFIG_SMP
;----------------------------------------------------------------
; First lines of code run by secondary before jumping to 'C'
;----------------------------------------------------------------
.section .text, "ax",@progbits
ENTRY(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
END(first_lines_of_secondary)
#endif
|
