1/* $FreeBSD$ */ 2 3/*- 4 * Copyright (C) 2010-2016 Nathan Whitehorn 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30#include "assym.inc" 31 32#include <sys/syscall.h> 33 34#include <machine/trap.h> 35#include <machine/param.h> 36#include <machine/spr.h> 37#include <machine/asm.h> 38#include <machine/vmparam.h> 39 40#ifdef _CALL_ELF 41.abiversion _CALL_ELF 42#endif 43 44/* Glue for linker script */ 45.globl kernbase 46.set kernbase, KERNBASE 47 48/* 49 * Globals 50 */ 51 .data 52 .align 3 53GLOBAL(__startkernel) 54 .llong begin 55GLOBAL(__endkernel) 56 .llong end 57GLOBAL(can_wakeup) 58 .llong 0x0 59 60 .align 4 61#define TMPSTKSZ 16384 /* 16K temporary stack */ 62GLOBAL(tmpstk) 63 .space TMPSTKSZ 64 65TOC_ENTRY(tmpstk) 66TOC_ENTRY(can_wakeup) 67 68#ifdef KDB 69#define TRAPSTKSZ 8192 /* 8k trap stack */ 70GLOBAL(trapstk) 71 .space TRAPSTKSZ 72TOC_ENTRY(trapstk) 73#endif 74 75 76/* 77 * Entry point for bootloaders that do not fully implement ELF and start 78 * at the beginning of the image (kexec, notably). In its own section so 79 * that it ends up before any linker-generated call stubs and actually at 80 * the beginning of the image. kexec on some systems also enters at 81 * (start of image) + 0x60, so put a spin loop there. 82 */ 83 .section ".text.kboot", "x", @progbits 84kbootentry: 85#ifdef __LITTLE_ENDIAN__ 86 RETURN_TO_NATIVE_ENDIAN 87#endif 88 b __start 89. = kbootentry + 0x40 /* Magic address used in platform layer */ 90 .global smp_spin_sem 91ap_kexec_spin_sem: 92 .long -1 93. = kbootentry + 0x60 /* Entry point for kexec APs */ 94ap_kexec_start: /* At 0x60 past start, copied to 0x60 by kexec */ 95 /* r3 set to CPU ID by kexec */ 96 97 /* Invalidate icache for low-memory copy and jump there */ 98 li %r0,0x80 99 dcbst 0,%r0 100 sync 101 icbi 0,%r0 102 isync 103 ba 0x80 /* Absolute branch to next inst */ 104 105. = kbootentry + 0x80 /* Aligned to cache line */ 1061: or 31,31,31 /* yield */ 107 sync 108 lwz %r1,0x40(0) /* Spin on ap_kexec_spin_sem */ 109 cmpw %r1,%r3 /* Until it equals our CPU ID */ 110 bne 1b 111 112 /* Released */ 113 or 2,2,2 /* unyield */ 114 115 /* Make sure that it will be software reset. Clear SRR1 */ 116 li %r1,0 117 mtsrr1 %r1 118 ba EXC_RST 119 120/* 121 * Now start the real text section 122 */ 123 124 .text 125 .globl btext 126btext: 127 128/* 129 * Main kernel entry point. 130 * 131 * Calling convention: 132 * r3: Flattened Device Tree pointer (or zero) 133 * r4: ignored 134 * r5: OF client interface pointer (or zero) 135 * r6: Loader metadata pointer (or zero) 136 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata 137 */ 138 .text 139_NAKED_ENTRY(__start) 140 141#ifdef __LITTLE_ENDIAN__ 142 RETURN_TO_NATIVE_ENDIAN 143#endif 144 /* Set 64-bit mode if not yet set before branching to C */ 145 mfmsr %r20 146 li %r21,1 147 insrdi %r20,%r21,1,0 148 mtmsrd %r20 149 isync 150 nop /* Make this block a multiple of 8 bytes */ 151 152 /* Set up the TOC pointer */ 153 b 0f 154 .align 3 1550: nop 156 bl 1f 157 .llong __tocbase + 0x8000 - . 1581: mflr %r2 159 ld %r1,0(%r2) 160 add %r2,%r1,%r2 161 162 /* Get load offset */ 163 ld %r31,-0x8000(%r2) /* First TOC entry is TOC base */ 164 subf %r31,%r31,%r2 /* Subtract from real TOC base to get base */ 165 166 /* Set up the stack pointer */ 167 bl 1f 168 .llong tmpstk + TMPSTKSZ - 96 - . 1691: mflr %r30 170 ld %r1,0(%r30) 171 add %r1,%r1,%r30 172 nop 173 174 /* Relocate kernel */ 175 std %r3,48(%r1) 176 std %r4,56(%r1) 177 std %r5,64(%r1) 178 std %r6,72(%r1) 179 std %r7,80(%r1) 180 181 bl 1f 182 .llong _DYNAMIC-. 1831: mflr %r3 184 ld %r4,0(%r3) 185 add %r3,%r4,%r3 186 mr %r4,%r31 187 bl elf_reloc_self 188 nop 189 ld %r3,48(%r1) 190 ld %r4,56(%r1) 191 ld %r5,64(%r1) 192 ld %r6,72(%r1) 193 ld %r7,80(%r1) 194 195 /* Begin CPU init */ 196 mr %r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */ 197 bl powerpc_init 198 nop 199 200 /* Set stack pointer to new value and branch to mi_startup */ 201 mr %r1, %r3 202 li %r3, 0 203 std %r3, 0(%r1) 204 bl mi_startup 205 nop 206 207 /* Unreachable */ 208 b . 209_END(__start) 210 211ASENTRY_NOPROF(__restartkernel_virtual) 212 /* 213 * When coming in via this entry point, we need to alter the SLB to 214 * shadow the segment register emulation entries in DMAP space. 215 * We need to do this dance because we are running with virtual-mode 216 * OpenFirmware and have not yet taken over the MMU. 217 * 218 * Assumptions: 219 * 1) The kernel is currently identity-mapped. 220 * 2) We are currently executing at an address compatible with 221 * real mode. 222 * 3) The first 16 SLB entries are emulating SRs. 223 * 4) The rest of the SLB is not in use. 224 * 5) OpenFirmware is not manipulating the SLB at runtime. 225 * 6) We are running on 64-bit AIM. 226 * 227 * Tested on a G5. 228 */ 229 mfmsr %r14 230 /* Switch to real mode because we are about to mess with the SLB. */ 231 andi. %r14, %r14, ~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l 232 mtmsr %r14 233 isync 234 /* Prepare variables for later use. */ 235 li %r14, 0 236 li %r18, 0 237 oris %r18, %r18, 0xc000 238 sldi %r18, %r18, 32 /* r18: 0xc000000000000000 */ 2391: 240 /* 241 * Loop over the first 16 SLB entries. 242 * Offset the SLBE into the DMAP, add 16 to the index, and write 243 * it back to the SLB. 244 */ 245 /* XXX add more safety checks */ 246 slbmfev %r15, %r14 247 slbmfee %r16, %r14 248 or %r16, %r16, %r14 /* index is 0-15 */ 249 ori %r16, %r16, 0x10 /* add 16 to index. */ 250 or %r16, %r16, %r18 /* SLBE DMAP offset */ 251 rldicr %r17, %r16, 0, 37 /* Invalidation SLBE */ 252 253 isync 254 slbie %r17 255 /* isync */ 256 slbmte %r15, %r16 257 isync 258 addi %r14, %r14, 1 259 cmpdi %r14, 16 260 blt 1b 261 262 /* 263 * Now that we are set up with a temporary direct map, we can 264 * continue with __restartkernel. Translation will be switched 265 * back on at the rfid, at which point we will be executing from 266 * the temporary direct map we just installed, until the kernel 267 * takes over responsibility for the MMU. 268 */ 269 bl __restartkernel 270 nop 271ASEND(__restartkernel_virtual) 272 273ASENTRY_NOPROF(__restartkernel) 274 /* 275 * r3-r7: arguments to go to __start 276 * r8: offset from current kernel address to apply 277 * r9: MSR to set when (atomically) jumping to __start + r8 278 */ 279 mtsrr1 %r9 280 bl 1f 2811: mflr %r25 282 add %r25,%r8,%r25 283 addi %r25,%r25,2f-1b 284 mtsrr0 %r25 285 rfid 2862: bl __start 287 nop 288ASEND(__restartkernel) 289 290#include <powerpc/aim/trap_subr64.S> 291