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
|
/*
* arch/ppc/kernel/head.S
*
* $Id$
*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
* Adapted for Power Macintosh by Paul Mackerras.
* Low-level exception handlers and MMU support
* rewritten by Paul Mackerras.
* Copyright (C) 1996 Paul Mackerras.
* MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* This file contains the low-level support and setup for the
* PowerPC platform, including trap and interrupt dispatch.
* Also included here is low-level thread/task switch support.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <libcpu/cpu.h>
#include <libcpu/io.h>
#include <rtems/score/targopts.h>
#include "asm.h"
#define SYNC \
sync; \
isync
#define KERNELBASE 0x0
#define MONITOR_ENTER \
mfmsr r10 ; \
ori r10,r10,MSR_IP ; \
mtmsr r10 ; \
li r10,0x63 ; \
sc
.text
.globl __rtems_entry_point
.type __rtems_entry_point,@function
__rtems_entry_point:
#ifdef DEBUG_EARLY_START
MONITOR_ENTER
#endif
/*
* PREP
* This is jumped to on prep systems right after the kernel is relocated
* to its proper place in memory by the boot loader. The expected layout
* of the regs is:
* r3: ptr to residual data
* r4: initrd_start or if no initrd then 0
* r5: initrd_end - unused if r4 is 0
* r6: Start of command line string
* r7: End of command line string
*
*/
mr r31,r3 /* save parameters */
mr r30,r4
mr r29,r5
mr r28,r6
mr r27,r7
/*
* Use the first pair of BAT registers to map the 1st 64MB
* of RAM to KERNELBASE.
*/
lis r11,KERNELBASE@h
ori r11,r11,0x7fe /* set up BAT registers for 604 */
li r8,2 /* R/W access */
mtspr DBAT0L,r8 /* N.B. 6xx (not 601) have valid */
mtspr DBAT0U,r11 /* bit in upper BAT register */
mtspr IBAT0L,r8
mtspr IBAT0U,r11
isync
/*
* we now have the 1st 64M of ram mapped with the bats.
*/
enter_C_code:
bl MMUon
/*
* stack = &__rtems_end + 4096
*/
addis r9,r0, __rtems_end+4096@ha
addi r9,r9, __rtems_end+4096@l
mr r1, r9
bl zero_bss
/*
* restore prep boot params
*/
mr r3,r31
mr r4,r30
mr r5,r29
mr r6,r28
mr r7,r27
bl save_boot_params
bl boot_card
bl _return_to_ppcbug
.globl MMUon
.type MMUon,@function
MMUon:
mfmsr r0
ori r0,r0, MSR_IP | MSR_RI | MSR_IR | MSR_DR | MSR_EE | MSR_FE0 | MSR_FE1
xori r0, r0, MSR_EE | MSR_IP | MSR_FP
mflr r11
mtsrr0 r11
mtsrr1 r0
SYNC
rfi
.globl MMUoff
.type MMUoff,@function
MMUoff:
mfmsr r0
ori r0,r0,MSR_IR| MSR_DR | MSR_IP
mflr r11
xori r0,r0,MSR_IR|MSR_DR
mtsrr0 r11
mtsrr1 r0
SYNC
rfi
.globl _return_to_ppcbug
.type _return_to_ppcbug,@function
_return_to_ppcbug:
mflr r30
bl MMUoff
MONITOR_ENTER
bl MMUon
mtctr r30
bctr
|
