1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * head.S - Common startup code for 68000 core
4 *
5 * 2012.10.21, Luis Alves <ljalvs@gmail.com>, S
6 * 68000 core based CPU's. Based o
7 * Coldfire by Greg Ungerer <gerg@s
8 * 68328 by D. Jeff Dionne <jeff@ry
9 * Kenneth Albanowski <kja
10 * The Silver Hammer Grou
11 *
12 */
13
14 #include <linux/linkage.h>
15 #include <linux/init.h>
16 #include <asm/asm-offsets.h>
17 #include <asm/thread_info.h>
18
19
20 /*********************************************
21 * UCSIMM and UCDIMM use CONFIG_MEMORY_RESERVE
22 *********************************************
23 #ifdef CONFIG_MEMORY_RESERVE
24 #define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)
25 #else
26 #define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)
27 #endif
28 /*********************************************
29
30 .global _start
31 .global _rambase
32 .global _ramvec
33 .global _ramstart
34 .global _ramend
35
36 #if defined(CONFIG_PILOT) || defined(CONFIG_IN
37 .global bootlogo_bits
38 #endif
39
40 /* Defining DEBUG_HEAD_CODE, serial port in 68
41 /* #define DEBUG_HEAD_CODE */
42 #undef DEBUG_HEAD_CODE
43
44 .data
45
46 /*********************************************
47 * RAM setup pointers. Used by the kernel to d
48 *********************************************
49
50 _rambase:
51 .long 0
52 _ramvec:
53 .long 0
54 _ramstart:
55 .long 0
56 _ramend:
57 .long 0
58
59 __HEAD
60
61 /*********************************************
62 * Entry point, where all begins!
63 *********************************************
64
65 _start:
66
67 /* Pilot need this specific signature at the s
68 #ifdef CONFIG_PILOT
69 .byte 0x4e, 0xfa, 0x00, 0x0a
70 .byte 'b', 'o', 'o', 't'
71 .word 10000
72 nop
73 moveq #0, %d0
74 movew %d0, 0xfffff618
75 movel #0x00011f07, 0xfffff114
76 #endif /* CONFIG_PILOT */
77
78 movew #0x2700, %sr
79
80 /*********************************************
81 * Setup PLL and wait for it to settle (in 68x
82 * Also, if enabled, init serial port.
83 *********************************************
84 #if defined(CONFIG_M68328) || \
85 defined(CONFIG_M68EZ328) || \
86 defined(CONFIG_M68VZ328)
87
88 /* Serial port setup. Should only be needed if
89 #ifdef DEBUG_HEAD_CODE
90 movew #0x0800, 0xfffff906
91 movew #0x010b, 0xfffff902
92 movew #0xe100, 0xfffff900
93 #endif /* DEBUG_HEAD */
94
95 #ifdef CONFIG_PILOT
96 movew #0x2410, 0xfffff200
97 #else
98 movew #0x2400, 0xfffff200
99 #endif
100 movew #0x0123, 0xfffff202
101 moveq #0, %d0
102 movew #16384, %d0
103 _pll_settle:
104 subw #1, %d0
105 bne _pll_settle
106 #endif /* CONFIG_M68x328 */
107
108
109 /*********************************************
110 * If running kernel from ROM some specific in
111 * (Assuming that everything is already init'e
112 *********************************************
113 #ifdef CONFIG_ROMKERNEL
114
115 /*********************************************
116 * Init chip registers (uCsimm specific)
117 *********************************************
118 #ifdef CONFIG_UCSIMM
119 moveb #0x00, 0xfffffb0b /* Wat
120 moveb #0x10, 0xfffff000 /* SCR
121 moveb #0x00, 0xfffff40b /* ena
122 moveb #0x00, 0xfffff423 /* ena
123 moveb #0x08, 0xfffffd0d /* dis
124 moveb #0x07, 0xfffffd0e /* lev
125 movew #0x8600, 0xfffff100 /* FLA
126 movew #0x018b, 0xfffff110 /* 2Me
127 movew #0x8f00, 0xfffffc00 /* DRA
128 movew #0x9667, 0xfffffc02 /* DRA
129 movew #0x0000, 0xfffff106 /* DRA
130 movew #0x068f, 0xfffff116 /* 8Me
131 moveb #0x40, 0xfffff300 /* IVR
132 movel #0x007FFFFF, %d0 /* IMR
133 movel %d0, 0xfffff304
134 moveb 0xfffff42b, %d0
135 andb #0xe0, %d0
136 moveb %d0, 0xfffff42b
137 #endif
138
139 /*********************************************
140 * Init LCD controller.
141 * (Assuming that LCD controller is already in
142 *********************************************
143 #ifdef CONFIG_INIT_LCD
144 #ifdef CONFIG_PILOT
145 moveb #0, 0xfffffA27
146 movel #_start, 0xfffffA00
147 moveb #0xa, 0xfffffA05
148 movew #0x9f, 0xFFFFFa08
149 movew #0x9f, 0xFFFFFa0a
150 moveb #9, 0xfffffa29
151 moveb #0, 0xfffffa25
152 moveb #0x04, 0xFFFFFa20
153 moveb #0x58, 0xfffffA27
154 moveb #0x85, 0xfffff429
155 moveb #0xd8, 0xfffffA27
156 moveb #0xc5, 0xfffff429
157 moveb #0xd5, 0xfffff429
158 movel #bootlogo_bits, 0xFFFFFA00
159 moveb #10, 0xFFFFFA05
160 movew #160, 0xFFFFFA08
161 movew #160, 0xFFFFFA0A
162 #else /* CONFIG_PILOT */
163 movel #bootlogo_bits, 0xfffffA00
164 moveb #0x28, 0xfffffA05
165 movew #0x280, 0xFFFFFa08
166 movew #0x1df, 0xFFFFFa0a
167 moveb #0, 0xfffffa29
168 moveb #0, 0xfffffa25
169 moveb #0x08, 0xFFFFFa20
170 moveb #0x01, 0xFFFFFA21
171 moveb #0x81, 0xfffffA27
172 movew #0xff00, 0xfffff412
173 #endif /* CONFIG_PILOT */
174 #endif /* CONFIG_INIT_LCD */
175
176 /*********************************************
177 * Kernel is running from FLASH/ROM (XIP)
178 * Copy init text & data to RAM
179 *********************************************
180 moveal #_etext, %a0
181 moveal #_sdata, %a1
182 moveal #__bss_start, %a2
183 _copy_initmem:
184 movel %a0@+, %a1@+
185 cmpal %a1, %a2
186 bhi _copy_initmem
187 #endif /* CONFIG_ROMKERNEL */
188
189 /*********************************************
190 * Setup basic memory information for kernel
191 *********************************************
192 movel #CONFIG_VECTORBASE,_ramvec
193 movel #CONFIG_RAMBASE,_rambase
194 movel #RAMEND, _ramend
195 lea __bss_stop,%a1
196 movel %a1,_ramstart
197
198 /*********************************************
199 * If the kernel is in RAM, move romfs to righ
200 * adjust _ramstart to where romfs ends.
201 *
202 * (Do this only if CONFIG_MTD_UCLINUX is true
203 *********************************************
204
205 #if defined(CONFIG_ROMFS_FS) && defined(CONFIG
206 defined(CONFIG_MTD_UCLINUX)
207 lea __bss_start, %a0
208 lea __bss_stop, %a1
209 movel %a0, %a2
210
211 movel 8(%a0), %d0
212 addql #8, %d0
213 andl #0xfffffffc, %d0
214
215 addl %d0, %a0
216 addl %d0, %a1
217 movel %a1, _ramstart
218 _copy_romfs:
219 movel -(%a0), -(%a1)
220 cmpl %a0, %a2
221 bne _copy_romfs
222 #endif /* CONFIG_ROMFS_FS && CONFIG_RAMKERNEL
223
224 /*********************************************
225 * Clear bss region
226 *********************************************
227 lea __bss_start, %a0
228 lea __bss_stop, %a1
229 _clear_bss:
230 movel #0, (%a0)+
231 cmpl %a0, %a1
232 bne _clear_bss
233
234 /*********************************************
235 * Load the current task pointer and stack.
236 *********************************************
237 lea init_thread_union,%a0
238 lea THREAD_SIZE(%a0),%sp
239 jsr start_kernel
240 _exit:
241 jmp _exit
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