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
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
|
/*****************************************************************************/
/*
* head.S -- common startup code for ColdFire CPUs.
*
* (C) Copyright 1999-2011, Greg Ungerer <gerg@snapgear.com>.
*/
/*****************************************************************************/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/asm-offsets.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/mcfmmu.h>
#include <asm/thread_info.h>
/*****************************************************************************/
/*
* If we don't have a fixed memory size, then lets build in code
* to auto detect the DRAM size. Obviously this is the preferred
* method, and should work for most boards. It won't work for those
* that do not have their RAM starting at address 0, and it only
* works on SDRAM (not boards fitted with SRAM).
*/
#if CONFIG_RAMSIZE != 0
.macro GET_MEM_SIZE
movel #CONFIG_RAMSIZE,%d0 /* hard coded memory size */
.endm
#elif defined(CONFIG_M5206) || defined(CONFIG_M5206e) || \
defined(CONFIG_M5249) || defined(CONFIG_M525x) || \
defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
defined(CONFIG_M5307) || defined(CONFIG_M5407)
/*
* Not all these devices have exactly the same DRAM controller,
* but the DCMR register is virtually identical - give or take
* a couple of bits. The only exception is the 5272 devices, their
* DRAM controller is quite different.
*/
.macro GET_MEM_SIZE
movel MCFSIM_DMR0,%d0 /* get mask for 1st bank */
btst #0,%d0 /* check if region enabled */
beq 1f
andl #0xfffc0000,%d0
beq 1f
addl #0x00040000,%d0 /* convert mask to size */
1:
movel MCFSIM_DMR1,%d1 /* get mask for 2nd bank */
btst #0,%d1 /* check if region enabled */
beq 2f
andl #0xfffc0000,%d1
beq 2f
addl #0x00040000,%d1
addl %d1,%d0 /* total mem size in d0 */
2:
.endm
#elif defined(CONFIG_M5272)
.macro GET_MEM_SIZE
movel MCFSIM_CSOR7,%d0 /* get SDRAM address mask */
andil #0xfffff000,%d0 /* mask out chip select options */
negl %d0 /* negate bits */
.endm
#elif defined(CONFIG_M520x)
.macro GET_MEM_SIZE
clrl %d0
movel MCFSIM_SDCS0, %d2 /* Get SDRAM chip select 0 config */
andl #0x1f, %d2 /* Get only the chip select size */
beq 3f /* Check if it is enabled */
addql #1, %d2 /* Form exponent */
moveql #1, %d0
lsll %d2, %d0 /* 2 ^ exponent */
3:
movel MCFSIM_SDCS1, %d2 /* Get SDRAM chip select 1 config */
andl #0x1f, %d2 /* Get only the chip select size */
beq 4f /* Check if it is enabled */
addql #1, %d2 /* Form exponent */
moveql #1, %d1
lsll %d2, %d1 /* 2 ^ exponent */
addl %d1, %d0 /* Total size of SDRAM in d0 */
4:
.endm
#else
#error "ERROR: I don't know how to probe your boards memory size?"
#endif
/*****************************************************************************/
/*
* Boards and platforms can do specific early hardware setup if
* they need to. Most don't need this, define away if not required.
*/
#ifndef PLATFORM_SETUP
#define PLATFORM_SETUP
#endif
/*****************************************************************************/
.global _start
.global _rambase
.global _ramvec
.global _ramstart
.global _ramend
#if defined(CONFIG_UBOOT)
.global _init_sp
#endif
/*****************************************************************************/
.data
/*
* During startup we store away the RAM setup. These are not in the
* bss, since their values are determined and written before the bss
* has been cleared.
*/
_rambase:
.long 0
_ramvec:
.long 0
_ramstart:
.long 0
_ramend:
.long 0
#if defined(CONFIG_UBOOT)
_init_sp:
.long 0
#endif
/*****************************************************************************/
__HEAD
#ifdef CONFIG_MMU
_start0:
jmp _start
.global kernel_pg_dir
.equ kernel_pg_dir,_start0
.equ .,_start0+0x1000
#endif
/*
* This is the codes first entry point. This is where it all
* begins...
*/
_start:
nop /* filler */
movew #0x2700, %sr /* no interrupts */
movel #CACHE_INIT,%d0 /* disable cache */
movec %d0,%CACR
nop
#if defined(CONFIG_UBOOT)
movel %sp,_init_sp /* save initial stack pointer */
#endif
#ifdef CONFIG_MBAR
movel #CONFIG_MBAR+1,%d0 /* configured MBAR address */
movec %d0,%MBAR /* set it */
#endif
/*
* Do any platform or board specific setup now. Most boards
* don't need anything. Those exceptions are define this in
* their board specific includes.
*/
PLATFORM_SETUP
/*
* Create basic memory configuration. Set VBR accordingly,
* and size memory.
*/
movel #CONFIG_VECTORBASE,%a7
movec %a7,%VBR /* set vectors addr */
movel %a7,_ramvec
movel #CONFIG_RAMBASE,%a7 /* mark the base of RAM */
movel %a7,_rambase
GET_MEM_SIZE /* macro code determines size */
addl %a7,%d0
movel %d0,_ramend /* set end ram addr */
/*
* Now that we know what the memory is, lets enable cache
* and get things moving. This is Coldfire CPU specific. Not
* all version cores have identical cache register setup. But
* it is very similar. Define the exact settings in the headers
* then the code here is the same for all.
*/
movel #ACR0_MODE,%d0 /* set RAM region for caching */
movec %d0,%ACR0
movel #ACR1_MODE,%d0 /* anything else to cache? */
movec %d0,%ACR1
#ifdef ACR2_MODE
movel #ACR2_MODE,%d0
movec %d0,%ACR2
movel #ACR3_MODE,%d0
movec %d0,%ACR3
#endif
movel #CACHE_MODE,%d0 /* enable cache */
movec %d0,%CACR
nop
#ifdef CONFIG_MMU
/*
* Identity mapping for the kernel region.
*/
movel #(MMUBASE+1),%d0 /* enable MMUBAR registers */
movec %d0,%MMUBAR
movel #MMUOR_CA,%d0 /* clear TLB entries */
movel %d0,MMUOR
movel #0,%d0 /* set ASID to 0 */
movec %d0,%asid
movel #MMUCR_EN,%d0 /* Enable the identity map */
movel %d0,MMUCR
nop /* sync i-pipeline */
movel #_vstart,%a0 /* jump to "virtual" space */
jmp %a0@
_vstart:
#endif /* CONFIG_MMU */
#ifdef CONFIG_ROMFS_FS
/*
* Move ROM filesystem above bss :-)
*/
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),%d0 /* copy dword */
movel %d0,-(%a1)
cmpl %a0,%a2 /* check if at end */
bne _copy_romfs
#else /* CONFIG_ROMFS_FS */
lea __bss_stop,%a1
movel %a1,_ramstart
#endif /* CONFIG_ROMFS_FS */
/*
* Zero out the bss region.
*/
lea __bss_start,%a0 /* get start of bss */
lea __bss_stop,%a1 /* get end of bss */
clrl %d0 /* set value */
_clear_bss:
movel %d0,(%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
#ifdef CONFIG_MMU
.global m68k_cputype
.global m68k_mmutype
.global m68k_fputype
.global m68k_machtype
movel #CPU_COLDFIRE,%d0
movel %d0,m68k_cputype /* Mark us as a ColdFire */
movel #MMU_COLDFIRE,%d0
movel %d0,m68k_mmutype
movel #FPU_COLDFIRE,%d0
movel %d0,m68k_fputype
movel #MACH_M54XX,%d0
movel %d0,m68k_machtype /* Mark us as a 54xx machine */
lea init_task,%a2 /* Set "current" init task */
#endif
/*
* Assember start up done, start code proper.
*/
jsr start_kernel /* start Linux kernel */
_exit:
jmp _exit /* should never get here */
/*****************************************************************************/
|
