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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
/*
* head.S - Common startup code for 68000 core based CPU's
*
* 2012.10.21, Luis Alves <ljalvs@gmail.com>, Single head.S file for all
* 68000 core based CPU's. Based on the sources from:
* Coldfire by Greg Ungerer <gerg@snapgear.com>
* 68328 by D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
* Kenneth Albanowski <kjahds@kjahds.com>,
* The Silver Hammer Group, Ltd.
*
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
/*****************************************************************************
* UCSIMM and UCDIMM use CONFIG_MEMORY_RESERVE to reserve some RAM
*****************************************************************************/
#ifdef CONFIG_MEMORY_RESERVE
#define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)-(CONFIG_MEMORY_RESERVE*0x100000)
#else
#define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)
#endif
/*****************************************************************************/
.global _start
.global _rambase
.global _ramvec
.global _ramstart
.global _ramend
#if defined(CONFIG_PILOT) || defined(CONFIG_INIT_LCD)
.global bootlogo_bits
#endif
/* Defining DEBUG_HEAD_CODE, serial port in 68x328 is inited */
/* #define DEBUG_HEAD_CODE */
#undef DEBUG_HEAD_CODE
.data
/*****************************************************************************
* RAM setup pointers. Used by the kernel to determine RAM location and size.
*****************************************************************************/
_rambase:
.long 0
_ramvec:
.long 0
_ramstart:
.long 0
_ramend:
.long 0
__HEAD
/*****************************************************************************
* Entry point, where all begins!
*****************************************************************************/
_start:
/* Pilot need this specific signature at the start of ROM */
#ifdef CONFIG_PILOT
.byte 0x4e, 0xfa, 0x00, 0x0a /* bra opcode (jmp 10 bytes) */
.byte 'b', 'o', 'o', 't'
.word 10000
nop
moveq #0, %d0
movew %d0, 0xfffff618 /* Watchdog off */
movel #0x00011f07, 0xfffff114 /* CS A1 Mask */
#endif /* CONFIG_PILOT */
movew #0x2700, %sr /* disable all interrupts */
/*****************************************************************************
* Setup PLL and wait for it to settle (in 68x328 cpu's).
* Also, if enabled, init serial port.
*****************************************************************************/
#if defined(CONFIG_M68328) || \
defined(CONFIG_M68EZ328) || \
defined(CONFIG_M68VZ328)
/* Serial port setup. Should only be needed if debugging this startup code. */
#ifdef DEBUG_HEAD_CODE
movew #0x0800, 0xfffff906 /* Ignore CTS */
movew #0x010b, 0xfffff902 /* BAUD to 9600 */
movew #0xe100, 0xfffff900 /* enable */
#endif /* DEBUG_HEAD */
#ifdef CONFIG_PILOT
movew #0x2410, 0xfffff200 /* PLLCR */
#else
movew #0x2400, 0xfffff200 /* PLLCR */
#endif
movew #0x0123, 0xfffff202 /* PLLFSR */
moveq #0, %d0
movew #16384, %d0 /* PLL settle wait loop */
_pll_settle:
subw #1, %d0
bne _pll_settle
#endif /* CONFIG_M68x328 */
/*****************************************************************************
* If running kernel from ROM some specific initialization has to be done.
* (Assuming that everything is already init'ed when running from RAM)
*****************************************************************************/
#ifdef CONFIG_ROMKERNEL
/*****************************************************************************
* Init chip registers (uCsimm specific)
*****************************************************************************/
#ifdef CONFIG_UCSIMM
moveb #0x00, 0xfffffb0b /* Watchdog off */
moveb #0x10, 0xfffff000 /* SCR */
moveb #0x00, 0xfffff40b /* enable chip select */
moveb #0x00, 0xfffff423 /* enable /DWE */
moveb #0x08, 0xfffffd0d /* disable hardmap */
moveb #0x07, 0xfffffd0e /* level 7 interrupt clear */
movew #0x8600, 0xfffff100 /* FLASH at 0x10c00000 */
movew #0x018b, 0xfffff110 /* 2Meg, enable, 0ws */
movew #0x8f00, 0xfffffc00 /* DRAM configuration */
movew #0x9667, 0xfffffc02 /* DRAM control */
movew #0x0000, 0xfffff106 /* DRAM at 0x00000000 */
movew #0x068f, 0xfffff116 /* 8Meg, enable, 0ws */
moveb #0x40, 0xfffff300 /* IVR */
movel #0x007FFFFF, %d0 /* IMR */
movel %d0, 0xfffff304
moveb 0xfffff42b, %d0
andb #0xe0, %d0
moveb %d0, 0xfffff42b
#endif
/*****************************************************************************
* Init LCD controller.
* (Assuming that LCD controller is already init'ed when running from RAM)
*****************************************************************************/
#ifdef CONFIG_INIT_LCD
#ifdef CONFIG_PILOT
moveb #0, 0xfffffA27 /* LCKCON */
movel #_start, 0xfffffA00 /* LSSA */
moveb #0xa, 0xfffffA05 /* LVPW */
movew #0x9f, 0xFFFFFa08 /* LXMAX */
movew #0x9f, 0xFFFFFa0a /* LYMAX */
moveb #9, 0xfffffa29 /* LBAR */
moveb #0, 0xfffffa25 /* LPXCD */
moveb #0x04, 0xFFFFFa20 /* LPICF */
moveb #0x58, 0xfffffA27 /* LCKCON */
moveb #0x85, 0xfffff429 /* PFDATA */
moveb #0xd8, 0xfffffA27 /* LCKCON */
moveb #0xc5, 0xfffff429 /* PFDATA */
moveb #0xd5, 0xfffff429 /* PFDATA */
movel #bootlogo_bits, 0xFFFFFA00 /* LSSA */
moveb #10, 0xFFFFFA05 /* LVPW */
movew #160, 0xFFFFFA08 /* LXMAX */
movew #160, 0xFFFFFA0A /* LYMAX */
#else /* CONFIG_PILOT */
movel #bootlogo_bits, 0xfffffA00 /* LSSA */
moveb #0x28, 0xfffffA05 /* LVPW */
movew #0x280, 0xFFFFFa08 /* LXMAX */
movew #0x1df, 0xFFFFFa0a /* LYMAX */
moveb #0, 0xfffffa29 /* LBAR */
moveb #0, 0xfffffa25 /* LPXCD */
moveb #0x08, 0xFFFFFa20 /* LPICF */
moveb #0x01, 0xFFFFFA21 /* -ve pol */
moveb #0x81, 0xfffffA27 /* LCKCON */
movew #0xff00, 0xfffff412 /* LCD pins */
#endif /* CONFIG_PILOT */
#endif /* CONFIG_INIT_LCD */
/*****************************************************************************
* Kernel is running from FLASH/ROM (XIP)
* Copy init text & data to RAM
*****************************************************************************/
moveal #_etext, %a0
moveal #_sdata, %a1
moveal #__bss_start, %a2
_copy_initmem:
movel %a0@+, %a1@+
cmpal %a1, %a2
bhi _copy_initmem
#endif /* CONFIG_ROMKERNEL */
/*****************************************************************************
* Setup basic memory information for kernel
*****************************************************************************/
movel #CONFIG_VECTORBASE,_ramvec /* set vector base location */
movel #CONFIG_RAMBASE,_rambase /* set the base of RAM */
movel #RAMEND, _ramend /* set end ram addr */
lea __bss_stop,%a1
movel %a1,_ramstart
/*****************************************************************************
* If the kernel is in RAM, move romfs to right above bss and
* adjust _ramstart to where romfs ends.
*
* (Do this only if CONFIG_MTD_UCLINUX is true)
*****************************************************************************/
#if defined(CONFIG_ROMFS_FS) && defined(CONFIG_RAMKERNEL) && \
defined(CONFIG_MTD_UCLINUX)
lea __bss_start, %a0 /* get start of bss */
lea __bss_stop, %a1 /* set up destination */
movel %a0, %a2 /* copy of bss start */
movel 8(%a0), %d0 /* get size of ROMFS */
addql #8, %d0 /* allow for rounding */
andl #0xfffffffc, %d0 /* whole words */
addl %d0, %a0 /* copy from end */
addl %d0, %a1 /* copy from end */
movel %a1, _ramstart /* set start of ram */
_copy_romfs:
movel -(%a0), -(%a1) /* copy dword */
cmpl %a0, %a2 /* check if at end */
bne _copy_romfs
#endif /* CONFIG_ROMFS_FS && CONFIG_RAMKERNEL && CONFIG_MTD_UCLINUX */
/*****************************************************************************
* Clear bss region
*****************************************************************************/
lea __bss_start, %a0 /* get start of bss */
lea __bss_stop, %a1 /* get end of bss */
_clear_bss:
movel #0, (%a0)+ /* clear each word */
cmpl %a0, %a1 /* check if at end */
bne _clear_bss
/*****************************************************************************
* Load the current task pointer and stack.
*****************************************************************************/
lea init_thread_union,%a0
lea THREAD_SIZE(%a0),%sp
jsr start_kernel /* start Linux kernel */
_exit:
jmp _exit /* should never get here */
|
