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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/ptrace.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/sizes.h>
#include <asm/thread_info.h>
#ifdef CONFIG_CPU_BIG_ENDIAN
#define OF_DT_MAGIC 0xd00dfeed
#else
#define OF_DT_MAGIC 0xedfe0dd0
#endif
.globl swapper_pg_dir
.equ swapper_pg_dir, TEXTADDR - 0x4000
/*
* Kernel startup entry point.
*/
.section ".head.text", "ax"
.type _stext, %function
ENTRY(_stext)
setgie.d ! Disable interrupt
isb
/*
* Disable I/D-cache and enable it at a proper time
*/
mfsr $r0, $mr8
li $r1, #~(CACHE_CTL_mskIC_EN|CACHE_CTL_mskDC_EN)
and $r0, $r0, $r1
mtsr $r0, $mr8
/*
* Process device tree blob
*/
andi $r0,$r2,#0x3
li $r10, 0
bne $r0, $r10, _nodtb
lwi $r0, [$r2]
li $r1, OF_DT_MAGIC
bne $r0, $r1, _nodtb
move $r10, $r2
_nodtb:
/*
* Create a temporary mapping area for booting, before start_kernel
*/
sethi $r4, hi20(swapper_pg_dir)
li $p0, (PAGE_OFFSET - PHYS_OFFSET)
sub $r4, $r4, $p0
tlbop FlushAll ! invalidate TLB\n"
isb
mtsr $r4, $L1_PPTB ! load page table pointer\n"
#ifdef CONFIG_CPU_DCACHE_DISABLE
#define MMU_CTL_NTCC MMU_CTL_CACHEABLE_NON
#else
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
#define MMU_CTL_NTCC MMU_CTL_CACHEABLE_WT
#else
#define MMU_CTL_NTCC MMU_CTL_CACHEABLE_WB
#endif
#endif
/* set NTC cacheability, mutliple page size in use */
mfsr $r3, $MMU_CTL
#if CONFIG_MEMORY_START >= 0xc0000000
ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC3)
#elif CONFIG_MEMORY_START >= 0x80000000
ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC2)
#elif CONFIG_MEMORY_START >= 0x40000000
ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC1)
#else
ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC0)
#endif
#ifdef CONFIG_ANDES_PAGE_SIZE_4KB
ori $r3, $r3, #(MMU_CTL_mskMPZIU)
#else
ori $r3, $r3, #(MMU_CTL_mskMPZIU|MMU_CTL_D8KB)
#endif
#ifdef CONFIG_HW_SUPPORT_UNALIGNMENT_ACCESS
li $r0, #MMU_CTL_UNA
or $r3, $r3, $r0
#endif
mtsr $r3, $MMU_CTL
isb
/* set page size and size of kernel image */
mfsr $r0, $MMU_CFG
srli $r3, $r0, MMU_CFG_offfEPSZ
zeb $r3, $r3
bnez $r3, _extra_page_size_support
#ifdef CONFIG_ANDES_PAGE_SIZE_4KB
li $r5, #SZ_4K ! Use 4KB page size
#else
li $r5, #SZ_8K ! Use 8KB page size
li $r3, #1
#endif
mtsr $r3, $TLB_MISC
b _image_size_check
_extra_page_size_support: ! Use epzs pages size
clz $r6, $r3
subri $r2, $r6, #31
li $r3, #1
sll $r3, $r3, $r2
/* MMU_CFG.EPSZ value -> meaning */
mul $r5, $r3, $r3
slli $r5, $r5, #14
/* MMU_CFG.EPSZ -> TLB_MISC.ACC_PSZ */
addi $r3, $r2, #0x2
mtsr $r3, $TLB_MISC
_image_size_check:
/* calculate the image maximum size accepted by TLB config */
andi $r6, $r0, MMU_CFG_mskTBW
andi $r0, $r0, MMU_CFG_mskTBS
srli $r6, $r6, MMU_CFG_offTBW
srli $r0, $r0, MMU_CFG_offTBS
addi $r6, $r6, #0x1 ! MMU_CFG.TBW value -> meaning
addi $r0, $r0, #0x2 ! MMU_CFG.TBS value -> meaning
sll $r0, $r6, $r0 ! entries = k-way * n-set
mul $r6, $r0, $r5 ! max size = entries * page size
/* check kernel image size */
la $r3, (_end - PAGE_OFFSET)
bgt $r3, $r6, __error
li $r2, #(PHYS_OFFSET + TLB_DATA_kernel_text_attr)
li $r3, PAGE_OFFSET
add $r6, $r6, $r3
_tlb:
mtsr $r3, $TLB_VPN
dsb
tlbop $r2, RWR
isb
add $r3, $r3, $r5
add $r2, $r2, $r5
bgt $r6, $r3, _tlb
mfsr $r3, $TLB_MISC ! setup access page size
li $r2, #~0xf
and $r3, $r3, $r2
#ifdef CONFIG_ANDES_PAGE_SIZE_8KB
ori $r3, $r3, #0x1
#endif
mtsr $r3, $TLB_MISC
mfsr $r0, $MISC_CTL ! Enable BTB and RTP and shadow sp
ori $r0, $r0, #MISC_init
mtsr $r0, $MISC_CTL
mfsr $p1, $PSW
li $r15, #~PSW_clr ! clear WBNA|DME|IME|DT|IT|POM|INTL|GIE
and $p1, $p1, $r15
ori $p1, $p1, #PSW_init
mtsr $p1, $IPSW ! when iret, it will automatically enable MMU
la $lp, __mmap_switched
mtsr $lp, $IPC
iret
nop
.type __switch_data, %object
__switch_data:
.long __bss_start ! $r6
.long _end ! $r7
.long __atags_pointer ! $atag_pointer
.long init_task ! $r9, move to $r25
.long init_thread_union + THREAD_SIZE ! $sp
/*
* The following fragment of code is executed with the MMU on in MMU mode,
* and uses absolute addresses; this is not position independent.
*/
.align
.type __mmap_switched, %function
__mmap_switched:
la $r3, __switch_data
lmw.bim $r6, [$r3], $r9, #0b0001
move $r25, $r9
move $fp, #0 ! Clear BSS (and zero $fp)
beq $r7, $r6, _RRT
1: swi.bi $fp, [$r6], #4
bne $r7, $r6, 1b
swi $r10, [$r8]
_RRT:
b start_kernel
__error:
b __error
|
