1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 /* 1 /*
3 * head.S - Common startup code for 68000 core 2 * head.S - Common startup code for 68000 core based CPU's
4 * 3 *
5 * 2012.10.21, Luis Alves <ljalvs@gmail.com>, S 4 * 2012.10.21, Luis Alves <ljalvs@gmail.com>, Single head.S file for all
6 * 68000 core based CPU's. Based o 5 * 68000 core based CPU's. Based on the sources from:
7 * Coldfire by Greg Ungerer <gerg@s 6 * Coldfire by Greg Ungerer <gerg@snapgear.com>
8 * 68328 by D. Jeff Dionne <jeff@ry 7 * 68328 by D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
9 * Kenneth Albanowski <kja 8 * Kenneth Albanowski <kjahds@kjahds.com>,
10 * The Silver Hammer Grou 9 * The Silver Hammer Group, Ltd.
11 * 10 *
12 */ 11 */
13 12
14 #include <linux/linkage.h> 13 #include <linux/linkage.h>
15 #include <linux/init.h> 14 #include <linux/init.h>
16 #include <asm/asm-offsets.h> 15 #include <asm/asm-offsets.h>
17 #include <asm/thread_info.h> 16 #include <asm/thread_info.h>
18 17
19 18
20 /********************************************* 19 /*****************************************************************************
21 * UCSIMM and UCDIMM use CONFIG_MEMORY_RESERVE 20 * UCSIMM and UCDIMM use CONFIG_MEMORY_RESERVE to reserve some RAM
22 ********************************************* 21 *****************************************************************************/
23 #ifdef CONFIG_MEMORY_RESERVE 22 #ifdef CONFIG_MEMORY_RESERVE
24 #define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE) 23 #define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)-(CONFIG_MEMORY_RESERVE*0x100000)
25 #else 24 #else
26 #define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE) 25 #define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)
27 #endif 26 #endif
28 /********************************************* 27 /*****************************************************************************/
29 28
30 .global _start 29 .global _start
31 .global _rambase 30 .global _rambase
32 .global _ramvec 31 .global _ramvec
33 .global _ramstart 32 .global _ramstart
34 .global _ramend 33 .global _ramend
35 34
36 #if defined(CONFIG_PILOT) || defined(CONFIG_IN 35 #if defined(CONFIG_PILOT) || defined(CONFIG_INIT_LCD)
37 .global bootlogo_bits 36 .global bootlogo_bits
38 #endif 37 #endif
39 38
40 /* Defining DEBUG_HEAD_CODE, serial port in 68 39 /* Defining DEBUG_HEAD_CODE, serial port in 68x328 is inited */
41 /* #define DEBUG_HEAD_CODE */ 40 /* #define DEBUG_HEAD_CODE */
42 #undef DEBUG_HEAD_CODE 41 #undef DEBUG_HEAD_CODE
43 42
44 .data 43 .data
45 44
46 /********************************************* 45 /*****************************************************************************
47 * RAM setup pointers. Used by the kernel to d 46 * RAM setup pointers. Used by the kernel to determine RAM location and size.
48 ********************************************* 47 *****************************************************************************/
49 48
50 _rambase: 49 _rambase:
51 .long 0 50 .long 0
52 _ramvec: 51 _ramvec:
53 .long 0 52 .long 0
54 _ramstart: 53 _ramstart:
55 .long 0 54 .long 0
56 _ramend: 55 _ramend:
57 .long 0 56 .long 0
58 57
59 __HEAD 58 __HEAD
60 59
61 /********************************************* 60 /*****************************************************************************
62 * Entry point, where all begins! 61 * Entry point, where all begins!
63 ********************************************* 62 *****************************************************************************/
64 63
65 _start: 64 _start:
66 65
67 /* Pilot need this specific signature at the s 66 /* Pilot need this specific signature at the start of ROM */
68 #ifdef CONFIG_PILOT 67 #ifdef CONFIG_PILOT
69 .byte 0x4e, 0xfa, 0x00, 0x0a 68 .byte 0x4e, 0xfa, 0x00, 0x0a /* bra opcode (jmp 10 bytes) */
70 .byte 'b', 'o', 'o', 't' 69 .byte 'b', 'o', 'o', 't'
71 .word 10000 70 .word 10000
72 nop 71 nop
73 moveq #0, %d0 72 moveq #0, %d0
74 movew %d0, 0xfffff618 73 movew %d0, 0xfffff618 /* Watchdog off */
75 movel #0x00011f07, 0xfffff114 74 movel #0x00011f07, 0xfffff114 /* CS A1 Mask */
76 #endif /* CONFIG_PILOT */ 75 #endif /* CONFIG_PILOT */
77 76
78 movew #0x2700, %sr 77 movew #0x2700, %sr /* disable all interrupts */
79 78
80 /********************************************* 79 /*****************************************************************************
81 * Setup PLL and wait for it to settle (in 68x 80 * Setup PLL and wait for it to settle (in 68x328 cpu's).
82 * Also, if enabled, init serial port. 81 * Also, if enabled, init serial port.
83 ********************************************* 82 *****************************************************************************/
84 #if defined(CONFIG_M68328) || \ 83 #if defined(CONFIG_M68328) || \
85 defined(CONFIG_M68EZ328) || \ 84 defined(CONFIG_M68EZ328) || \
86 defined(CONFIG_M68VZ328) 85 defined(CONFIG_M68VZ328)
87 86
88 /* Serial port setup. Should only be needed if 87 /* Serial port setup. Should only be needed if debugging this startup code. */
89 #ifdef DEBUG_HEAD_CODE 88 #ifdef DEBUG_HEAD_CODE
90 movew #0x0800, 0xfffff906 89 movew #0x0800, 0xfffff906 /* Ignore CTS */
91 movew #0x010b, 0xfffff902 90 movew #0x010b, 0xfffff902 /* BAUD to 9600 */
92 movew #0xe100, 0xfffff900 91 movew #0xe100, 0xfffff900 /* enable */
93 #endif /* DEBUG_HEAD */ 92 #endif /* DEBUG_HEAD */
94 93
95 #ifdef CONFIG_PILOT 94 #ifdef CONFIG_PILOT
96 movew #0x2410, 0xfffff200 95 movew #0x2410, 0xfffff200 /* PLLCR */
97 #else 96 #else
98 movew #0x2400, 0xfffff200 97 movew #0x2400, 0xfffff200 /* PLLCR */
99 #endif 98 #endif
100 movew #0x0123, 0xfffff202 99 movew #0x0123, 0xfffff202 /* PLLFSR */
101 moveq #0, %d0 100 moveq #0, %d0
102 movew #16384, %d0 101 movew #16384, %d0 /* PLL settle wait loop */
103 _pll_settle: 102 _pll_settle:
104 subw #1, %d0 103 subw #1, %d0
105 bne _pll_settle 104 bne _pll_settle
106 #endif /* CONFIG_M68x328 */ 105 #endif /* CONFIG_M68x328 */
107 106
108 107
109 /********************************************* 108 /*****************************************************************************
110 * If running kernel from ROM some specific in 109 * If running kernel from ROM some specific initialization has to be done.
111 * (Assuming that everything is already init'e 110 * (Assuming that everything is already init'ed when running from RAM)
112 ********************************************* 111 *****************************************************************************/
113 #ifdef CONFIG_ROMKERNEL 112 #ifdef CONFIG_ROMKERNEL
114 113
115 /********************************************* 114 /*****************************************************************************
116 * Init chip registers (uCsimm specific) 115 * Init chip registers (uCsimm specific)
117 ********************************************* 116 *****************************************************************************/
118 #ifdef CONFIG_UCSIMM 117 #ifdef CONFIG_UCSIMM
119 moveb #0x00, 0xfffffb0b /* Wat 118 moveb #0x00, 0xfffffb0b /* Watchdog off */
120 moveb #0x10, 0xfffff000 /* SCR 119 moveb #0x10, 0xfffff000 /* SCR */
121 moveb #0x00, 0xfffff40b /* ena 120 moveb #0x00, 0xfffff40b /* enable chip select */
122 moveb #0x00, 0xfffff423 /* ena 121 moveb #0x00, 0xfffff423 /* enable /DWE */
123 moveb #0x08, 0xfffffd0d /* dis 122 moveb #0x08, 0xfffffd0d /* disable hardmap */
124 moveb #0x07, 0xfffffd0e /* lev 123 moveb #0x07, 0xfffffd0e /* level 7 interrupt clear */
125 movew #0x8600, 0xfffff100 /* FLA 124 movew #0x8600, 0xfffff100 /* FLASH at 0x10c00000 */
126 movew #0x018b, 0xfffff110 /* 2Me 125 movew #0x018b, 0xfffff110 /* 2Meg, enable, 0ws */
127 movew #0x8f00, 0xfffffc00 /* DRA 126 movew #0x8f00, 0xfffffc00 /* DRAM configuration */
128 movew #0x9667, 0xfffffc02 /* DRA 127 movew #0x9667, 0xfffffc02 /* DRAM control */
129 movew #0x0000, 0xfffff106 /* DRA 128 movew #0x0000, 0xfffff106 /* DRAM at 0x00000000 */
130 movew #0x068f, 0xfffff116 /* 8Me 129 movew #0x068f, 0xfffff116 /* 8Meg, enable, 0ws */
131 moveb #0x40, 0xfffff300 /* IVR 130 moveb #0x40, 0xfffff300 /* IVR */
132 movel #0x007FFFFF, %d0 /* IMR 131 movel #0x007FFFFF, %d0 /* IMR */
133 movel %d0, 0xfffff304 132 movel %d0, 0xfffff304
134 moveb 0xfffff42b, %d0 133 moveb 0xfffff42b, %d0
135 andb #0xe0, %d0 134 andb #0xe0, %d0
136 moveb %d0, 0xfffff42b 135 moveb %d0, 0xfffff42b
137 #endif 136 #endif
138 137
139 /********************************************* 138 /*****************************************************************************
140 * Init LCD controller. 139 * Init LCD controller.
141 * (Assuming that LCD controller is already in 140 * (Assuming that LCD controller is already init'ed when running from RAM)
142 ********************************************* 141 *****************************************************************************/
143 #ifdef CONFIG_INIT_LCD 142 #ifdef CONFIG_INIT_LCD
144 #ifdef CONFIG_PILOT 143 #ifdef CONFIG_PILOT
145 moveb #0, 0xfffffA27 144 moveb #0, 0xfffffA27 /* LCKCON */
146 movel #_start, 0xfffffA00 145 movel #_start, 0xfffffA00 /* LSSA */
147 moveb #0xa, 0xfffffA05 146 moveb #0xa, 0xfffffA05 /* LVPW */
148 movew #0x9f, 0xFFFFFa08 147 movew #0x9f, 0xFFFFFa08 /* LXMAX */
149 movew #0x9f, 0xFFFFFa0a 148 movew #0x9f, 0xFFFFFa0a /* LYMAX */
150 moveb #9, 0xfffffa29 149 moveb #9, 0xfffffa29 /* LBAR */
151 moveb #0, 0xfffffa25 150 moveb #0, 0xfffffa25 /* LPXCD */
152 moveb #0x04, 0xFFFFFa20 151 moveb #0x04, 0xFFFFFa20 /* LPICF */
153 moveb #0x58, 0xfffffA27 152 moveb #0x58, 0xfffffA27 /* LCKCON */
154 moveb #0x85, 0xfffff429 153 moveb #0x85, 0xfffff429 /* PFDATA */
155 moveb #0xd8, 0xfffffA27 154 moveb #0xd8, 0xfffffA27 /* LCKCON */
156 moveb #0xc5, 0xfffff429 155 moveb #0xc5, 0xfffff429 /* PFDATA */
157 moveb #0xd5, 0xfffff429 156 moveb #0xd5, 0xfffff429 /* PFDATA */
158 movel #bootlogo_bits, 0xFFFFFA00 157 movel #bootlogo_bits, 0xFFFFFA00 /* LSSA */
159 moveb #10, 0xFFFFFA05 158 moveb #10, 0xFFFFFA05 /* LVPW */
160 movew #160, 0xFFFFFA08 159 movew #160, 0xFFFFFA08 /* LXMAX */
161 movew #160, 0xFFFFFA0A 160 movew #160, 0xFFFFFA0A /* LYMAX */
162 #else /* CONFIG_PILOT */ 161 #else /* CONFIG_PILOT */
163 movel #bootlogo_bits, 0xfffffA00 162 movel #bootlogo_bits, 0xfffffA00 /* LSSA */
164 moveb #0x28, 0xfffffA05 163 moveb #0x28, 0xfffffA05 /* LVPW */
165 movew #0x280, 0xFFFFFa08 164 movew #0x280, 0xFFFFFa08 /* LXMAX */
166 movew #0x1df, 0xFFFFFa0a 165 movew #0x1df, 0xFFFFFa0a /* LYMAX */
167 moveb #0, 0xfffffa29 166 moveb #0, 0xfffffa29 /* LBAR */
168 moveb #0, 0xfffffa25 167 moveb #0, 0xfffffa25 /* LPXCD */
169 moveb #0x08, 0xFFFFFa20 168 moveb #0x08, 0xFFFFFa20 /* LPICF */
170 moveb #0x01, 0xFFFFFA21 169 moveb #0x01, 0xFFFFFA21 /* -ve pol */
171 moveb #0x81, 0xfffffA27 170 moveb #0x81, 0xfffffA27 /* LCKCON */
172 movew #0xff00, 0xfffff412 171 movew #0xff00, 0xfffff412 /* LCD pins */
173 #endif /* CONFIG_PILOT */ 172 #endif /* CONFIG_PILOT */
174 #endif /* CONFIG_INIT_LCD */ 173 #endif /* CONFIG_INIT_LCD */
175 174
176 /********************************************* 175 /*****************************************************************************
177 * Kernel is running from FLASH/ROM (XIP) 176 * Kernel is running from FLASH/ROM (XIP)
178 * Copy init text & data to RAM 177 * Copy init text & data to RAM
179 ********************************************* 178 *****************************************************************************/
180 moveal #_etext, %a0 179 moveal #_etext, %a0
181 moveal #_sdata, %a1 180 moveal #_sdata, %a1
182 moveal #__bss_start, %a2 181 moveal #__bss_start, %a2
183 _copy_initmem: 182 _copy_initmem:
184 movel %a0@+, %a1@+ 183 movel %a0@+, %a1@+
185 cmpal %a1, %a2 184 cmpal %a1, %a2
186 bhi _copy_initmem 185 bhi _copy_initmem
187 #endif /* CONFIG_ROMKERNEL */ 186 #endif /* CONFIG_ROMKERNEL */
188 187
189 /********************************************* 188 /*****************************************************************************
190 * Setup basic memory information for kernel 189 * Setup basic memory information for kernel
191 ********************************************* 190 *****************************************************************************/
192 movel #CONFIG_VECTORBASE,_ramvec 191 movel #CONFIG_VECTORBASE,_ramvec /* set vector base location */
193 movel #CONFIG_RAMBASE,_rambase 192 movel #CONFIG_RAMBASE,_rambase /* set the base of RAM */
194 movel #RAMEND, _ramend 193 movel #RAMEND, _ramend /* set end ram addr */
195 lea __bss_stop,%a1 194 lea __bss_stop,%a1
196 movel %a1,_ramstart 195 movel %a1,_ramstart
197 196
198 /********************************************* 197 /*****************************************************************************
199 * If the kernel is in RAM, move romfs to righ 198 * If the kernel is in RAM, move romfs to right above bss and
200 * adjust _ramstart to where romfs ends. 199 * adjust _ramstart to where romfs ends.
201 * 200 *
202 * (Do this only if CONFIG_MTD_UCLINUX is true 201 * (Do this only if CONFIG_MTD_UCLINUX is true)
203 ********************************************* 202 *****************************************************************************/
204 203
205 #if defined(CONFIG_ROMFS_FS) && defined(CONFIG 204 #if defined(CONFIG_ROMFS_FS) && defined(CONFIG_RAMKERNEL) && \
206 defined(CONFIG_MTD_UCLINUX) 205 defined(CONFIG_MTD_UCLINUX)
207 lea __bss_start, %a0 206 lea __bss_start, %a0 /* get start of bss */
208 lea __bss_stop, %a1 207 lea __bss_stop, %a1 /* set up destination */
209 movel %a0, %a2 208 movel %a0, %a2 /* copy of bss start */
210 209
211 movel 8(%a0), %d0 210 movel 8(%a0), %d0 /* get size of ROMFS */
212 addql #8, %d0 211 addql #8, %d0 /* allow for rounding */
213 andl #0xfffffffc, %d0 212 andl #0xfffffffc, %d0 /* whole words */
214 213
215 addl %d0, %a0 214 addl %d0, %a0 /* copy from end */
216 addl %d0, %a1 215 addl %d0, %a1 /* copy from end */
217 movel %a1, _ramstart 216 movel %a1, _ramstart /* set start of ram */
218 _copy_romfs: 217 _copy_romfs:
219 movel -(%a0), -(%a1) 218 movel -(%a0), -(%a1) /* copy dword */
220 cmpl %a0, %a2 219 cmpl %a0, %a2 /* check if at end */
221 bne _copy_romfs 220 bne _copy_romfs
222 #endif /* CONFIG_ROMFS_FS && CONFIG_RAMKERNEL 221 #endif /* CONFIG_ROMFS_FS && CONFIG_RAMKERNEL && CONFIG_MTD_UCLINUX */
223 222
224 /********************************************* 223 /*****************************************************************************
225 * Clear bss region 224 * Clear bss region
226 ********************************************* 225 *****************************************************************************/
227 lea __bss_start, %a0 226 lea __bss_start, %a0 /* get start of bss */
228 lea __bss_stop, %a1 227 lea __bss_stop, %a1 /* get end of bss */
229 _clear_bss: 228 _clear_bss:
230 movel #0, (%a0)+ 229 movel #0, (%a0)+ /* clear each word */
231 cmpl %a0, %a1 230 cmpl %a0, %a1 /* check if at end */
232 bne _clear_bss 231 bne _clear_bss
233 232
234 /********************************************* 233 /*****************************************************************************
235 * Load the current task pointer and stack. 234 * Load the current task pointer and stack.
236 ********************************************* 235 *****************************************************************************/
237 lea init_thread_union,%a0 236 lea init_thread_union,%a0
238 lea THREAD_SIZE(%a0),%sp 237 lea THREAD_SIZE(%a0),%sp
239 jsr start_kernel 238 jsr start_kernel /* start Linux kernel */
240 _exit: 239 _exit:
241 jmp _exit 240 jmp _exit /* should never get here */
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