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