1 2/*- 3 * Copyright (C) 2010-2016 Nathan Whitehorn 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include "assym.inc" 28 29#include <sys/syscall.h> 30 31#include <machine/trap.h> 32#include <machine/param.h> 33#include <machine/spr.h> 34#include <machine/asm.h> 35#include <machine/vmparam.h> 36 37#ifdef _CALL_ELF 38.abiversion _CALL_ELF 39#endif 40 41/* Glue for linker script */ 42.globl kernbase 43.set kernbase, KERNBASE 44 45/* 46 * Globals 47 */ 48 .data 49 .align 3 50GLOBAL(__startkernel) 51 .llong begin 52GLOBAL(__endkernel) 53 .llong end 54GLOBAL(can_wakeup) 55 .llong 0x0 56 57 .align 4 58#define TMPSTKSZ 16384 /* 16K temporary stack */ 59GLOBAL(tmpstk) 60 .space TMPSTKSZ 61 62TOC_ENTRY(tmpstk) 63TOC_ENTRY(can_wakeup) 64 65#ifdef KDB 66#define TRAPSTKSZ 8192 /* 8k trap stack */ 67GLOBAL(trapstk) 68 .space TRAPSTKSZ 69TOC_ENTRY(trapstk) 70#endif 71 72 73/* 74 * Entry point for bootloaders that do not fully implement ELF and start 75 * at the beginning of the image (kexec, notably). In its own section so 76 * that it ends up before any linker-generated call stubs and actually at 77 * the beginning of the image. kexec on some systems also enters at 78 * (start of image) + 0x60, so put a spin loop there. 79 */ 80 .section ".text.kboot", "x", @progbits 81kbootentry: 82#ifdef __LITTLE_ENDIAN__ 83 RETURN_TO_NATIVE_ENDIAN 84#endif 85 b __start 86. = kbootentry + 0x40 /* Magic address used in platform layer */ 87 .global smp_spin_sem 88ap_kexec_spin_sem: 89 .long -1 90. = kbootentry + 0x60 /* Entry point for kexec APs */ 91ap_kexec_start: /* At 0x60 past start, copied to 0x60 by kexec */ 92 /* r3 set to CPU ID by kexec */ 93 94 /* Invalidate icache for low-memory copy and jump there */ 95 li %r0,0x80 96 dcbst 0,%r0 97 sync 98 icbi 0,%r0 99 isync 100 ba 0x80 /* Absolute branch to next inst */ 101 102. = kbootentry + 0x80 /* Aligned to cache line */ 1031: or 31,31,31 /* yield */ 104 sync 105 lwz %r1,0x40(0) /* Spin on ap_kexec_spin_sem */ 106 cmpw %r1,%r3 /* Until it equals our CPU ID */ 107 bne 1b 108 109 /* Released */ 110 or 2,2,2 /* unyield */ 111 112 /* Make sure that it will be software reset. Clear SRR1 */ 113 li %r1,0 114 mtsrr1 %r1 115 ba EXC_RST 116 117/* 118 * Now start the real text section 119 */ 120 121 .text 122 .globl btext 123btext: 124 125/* 126 * Main kernel entry point. 127 * 128 * Calling convention: 129 * r3: Flattened Device Tree pointer (or zero) 130 * r4: ignored 131 * r5: OF client interface pointer (or zero) 132 * r6: Loader metadata pointer (or zero) 133 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata 134 */ 135 .text 136_NAKED_ENTRY(__start) 137 138#ifdef __LITTLE_ENDIAN__ 139 RETURN_TO_NATIVE_ENDIAN 140#endif 141 /* Set 64-bit mode if not yet set before branching to C */ 142 mfmsr %r20 143 li %r21,1 144 insrdi %r20,%r21,1,0 145 mtmsrd %r20 146 isync 147 nop /* Make this block a multiple of 8 bytes */ 148 149 /* Set up the TOC pointer */ 150 b 0f 151 .align 3 1520: nop 153 bl 1f 154 .llong __tocbase + 0x8000 - . 1551: mflr %r2 156 ld %r1,0(%r2) 157 add %r2,%r1,%r2 158 159 /* Get load offset */ 160 ld %r31,-0x8000(%r2) /* First TOC entry is TOC base */ 161 subf %r31,%r31,%r2 /* Subtract from real TOC base to get base */ 162 163 /* Set up the stack pointer */ 164 bl 1f 165 .llong tmpstk + TMPSTKSZ - 96 - . 1661: mflr %r30 167 ld %r1,0(%r30) 168 add %r1,%r1,%r30 169 nop 170 171 /* Relocate kernel */ 172 std %r3,48(%r1) 173 std %r4,56(%r1) 174 std %r5,64(%r1) 175 std %r6,72(%r1) 176 std %r7,80(%r1) 177 178 bl 1f 179 .llong _DYNAMIC-. 1801: mflr %r3 181 ld %r4,0(%r3) 182 add %r3,%r4,%r3 183 mr %r4,%r31 184 bl elf_reloc_self 185 nop 186 ld %r3,48(%r1) 187 ld %r4,56(%r1) 188 ld %r5,64(%r1) 189 ld %r6,72(%r1) 190 ld %r7,80(%r1) 191 192 /* Begin CPU init */ 193 mr %r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */ 194 bl powerpc_init 195 nop 196 197 /* Set stack pointer to new value and branch to mi_startup */ 198 mr %r1, %r3 199 li %r3, 0 200 std %r3, 0(%r1) 201 bl mi_startup 202 nop 203 204 /* Unreachable */ 205 b . 206_END(__start) 207 208ASENTRY_NOPROF(__restartkernel_virtual) 209 /* 210 * When coming in via this entry point, we need to alter the SLB to 211 * shadow the segment register emulation entries in DMAP space. 212 * We need to do this dance because we are running with virtual-mode 213 * OpenFirmware and have not yet taken over the MMU. 214 * 215 * Assumptions: 216 * 1) The kernel is currently identity-mapped. 217 * 2) We are currently executing at an address compatible with 218 * real mode. 219 * 3) The first 16 SLB entries are emulating SRs. 220 * 4) The rest of the SLB is not in use. 221 * 5) OpenFirmware is not manipulating the SLB at runtime. 222 * 6) We are running on 64-bit AIM. 223 * 224 * Tested on a G5. 225 */ 226 mfmsr %r14 227 /* Switch to real mode because we are about to mess with the SLB. */ 228 andi. %r14, %r14, ~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l 229 mtmsr %r14 230 isync 231 /* Prepare variables for later use. */ 232 li %r14, 0 233 li %r18, 0 234 oris %r18, %r18, 0xc000 235 sldi %r18, %r18, 32 /* r18: 0xc000000000000000 */ 2361: 237 /* 238 * Loop over the first 16 SLB entries. 239 * Offset the SLBE into the DMAP, add 16 to the index, and write 240 * it back to the SLB. 241 */ 242 /* XXX add more safety checks */ 243 slbmfev %r15, %r14 244 slbmfee %r16, %r14 245 or %r16, %r16, %r14 /* index is 0-15 */ 246 ori %r16, %r16, 0x10 /* add 16 to index. */ 247 or %r16, %r16, %r18 /* SLBE DMAP offset */ 248 rldicr %r17, %r16, 0, 37 /* Invalidation SLBE */ 249 250 isync 251 slbie %r17 252 /* isync */ 253 slbmte %r15, %r16 254 isync 255 addi %r14, %r14, 1 256 cmpdi %r14, 16 257 blt 1b 258 259 /* 260 * Now that we are set up with a temporary direct map, we can 261 * continue with __restartkernel. Translation will be switched 262 * back on at the rfid, at which point we will be executing from 263 * the temporary direct map we just installed, until the kernel 264 * takes over responsibility for the MMU. 265 */ 266 bl __restartkernel 267 nop 268ASEND(__restartkernel_virtual) 269 270ASENTRY_NOPROF(__restartkernel) 271 /* 272 * r3-r7: arguments to go to __start 273 * r8: offset from current kernel address to apply 274 * r9: MSR to set when (atomically) jumping to __start + r8 275 */ 276 mtsrr1 %r9 277 bl 1f 2781: mflr %r25 279 add %r25,%r8,%r25 280 addi %r25,%r25,2f-1b 281 mtsrr0 %r25 282 rfid 2832: bl __start 284 nop 285ASEND(__restartkernel) 286 287#include <powerpc/aim/trap_subr64.S> 288