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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 | /* SPDX-License-Identifier: GPL-2.0 */ /* * 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 */ |