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
|
# IBM_PROLOG_BEGIN_TAG
# This is an automatically generated prolog.
#
# $Source: src/bootloader/bl_start.S $
#
# OpenPOWER HostBoot Project
#
# Contributors Listed Below - COPYRIGHT 2015,2016
# [+] International Business Machines Corp.
#
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied. See the License for the specific language governing
# permissions and limitations under the License.
#
# IBM_PROLOG_END_TAG
.include "kernel/ppcconsts.S"
.section .text.bootloaderasm
.global _start
_start:
;// Set thread priority high.
or 2,2,2
;// Clear MSR[TA] (bit 1) and enable MSR[ME] (bit 51).
mfmsr r2
rldicl r2,r2,1,1 ;// Clear bit 1 - result [1-63,0]
rotrdi r2,r2,1 ;// Rotate right 1 - result [0,63]
ori r2,r2,4096 ;// Set bit 51
;// Set up SRR0 / SRR1 to enable new MSR.
mtsrr1 r2
li r2, _start_postmsr@l
mtsrr0 r2
b _start_postmsr
_start_postmsr:
;// Determine if this is the first thread.
li r4, 2
;// Read spinlock value.
lis r2, kernel_other_thread_spinlock@h
ori r2, r2, kernel_other_thread_spinlock@l
lwsync
1:
ldarx r3, 0, r2
cmpwi r3, 0 ;// Non-zero means this thread wasn't first.
bnel cr0, _other_thread_error ;// Handle having multiple threads started
stdcx. r4, 0, r2 ;// Attempt to store 2.
bne 1b ;// Loop until sucessful at stwcx.
isync
b _main
/* @TODO RTC:133821 might not be needed
;// Relocate code
bl pre_relocate ;// fill LR with address
pre_relocate:
mflr r2
lis r1,0x0010
cmpl cr0,r2,r1 ;// Check LR is less than 1MB
blt finished_relocate ;// No need to relocate if less than 1MB
;// Get addresses for relocation.
;// Write address in r5
;// Read address in r1
li r5,0
lis r1, -1 ;// fill r1 with ffff..ff0000
and r1,r1,r2 ;// and with pre_relocate's address from r2 to get start of
;// rom section.
;// Update LR to low address.
clrldi r2,r2,48 ;// Equiv to ~(0x0FFFF)
mtlr 2
;// Moving 1MB , so load r2 with (1MB / 8 bytes per word)
lis r2, 0x2
mtctr r2
relocate_loop:
;// The dcbst/sync/icbi/isync sequence comes from PowerISA
ld r4, 0(r1)
std r4, 0(r5)
dcbst 0,r5
sync
icbi 0,r5
isync
addi r1,r1,8
addi r5,r5,8
bdnz+ relocate_loop
;// Now that we've relocated, erase exception prefix.
mfmsr r11
rldicl r11,r11,57,1 ;// Erase bit 6 ( equiv to r11 & ~(0x40))
rotldi r11,r11,7
mtmsr r11
;// Jump to low address.
blr
finished_relocate:
;// Jump to main.
b _main
@TODO RTC:133821 might not be needed */
;// _main:
;// Set up stack and TOC and call kernel's main.
_main:
;// Set up initial TOC Base
lis r2, main@h
ori r2, r2, main@l
ld r2,8(r2)
;// Set up initial stack, space for 8 double-words
lis r1, kernel_stack@h
ori r1, r1, kernel_stack@l
addi r1, r1, 16320
;// Call main.
bl main
_main_loop:
b _main_loop
;// @fn _other_thread_error:
;// Used for threads other than first to handle this unexpected condition.
_other_thread_error:
;// Read spinlock value.
lis r2, kernel_other_thread_spinlock@h
ori r2, r2, kernel_other_thread_spinlock@l
1:
ld r3, 0(r2)
;// Loop until value is 1...
cmpi cr0, r3, 1
beq task_end_stub ;// End the multiple threads
or 1,1,1 ;// Lower thread priority.
b 1b
;// @fn task_end_stub
;// Stub to call a TASK_END syscall in the event that a task 'returns' from
;// its entry point. We cannot call task_end() directly because profiling
;// inserts garbage code into the task_end C function.
.global task_end_stub
task_end_stub:
mr r4, r3 ;// Move current rc (r3) to status value (r4)
li r3, 2 ;// TASK_END -> r3 (syscall number)
sc
.section .data
.balign 1024
kernel_stack:
.space 4*1024
.balign 8
.global data_sandbox
data_sandbox:
.space 64
.global kernel_other_thread_spinlock
kernel_other_thread_spinlock:
.space 8
.global g_blScratchSpace
g_blScratchSpace:
.space 8
|
