1/* $NetBSD: locore.S,v 1.14 2003/04/20 16:21:40 thorpej Exp $ */ 2 3/*- 4 * Copyright 2011 Semihalf 5 * Copyright (C) 1994-1997 Mark Brinicombe 6 * Copyright (C) 1994 Brini 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by Brini. 20 * 4. The name of Brini may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL BRINI BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 * 34 */ 35 36#include "assym.s" 37#include <sys/syscall.h> 38#include <machine/asm.h> 39#include <machine/armreg.h> 40#include <machine/pte.h> 41 42__FBSDID("$FreeBSD$"); 43 44/* What size should this really be ? It is only used by initarm() */ 45#define INIT_ARM_STACK_SIZE (2048 * 4) 46 47#define CPWAIT_BRANCH \ 48 sub pc, pc, #4 49 50#define CPWAIT(tmp) \ 51 mrc p15, 0, tmp, c2, c0, 0 /* arbitrary read of CP15 */ ;\ 52 mov tmp, tmp /* wait for it to complete */ ;\ 53 CPWAIT_BRANCH /* branch to next insn */ 54 55/* 56 * This is for kvm_mkdb, and should be the address of the beginning 57 * of the kernel text segment (not necessarily the same as kernbase). 58 */ 59 .text 60 .align 0 61.globl kernbase 62.set kernbase,KERNBASE 63.globl physaddr 64.set physaddr,PHYSADDR 65 66/* 67 * On entry for FreeBSD boot ABI: 68 * r0 - metadata pointer or 0 (boothowto on AT91's boot2) 69 * r1 - if (r0 == 0) then metadata pointer 70 * On entry for Linux boot ABI: 71 * r0 - 0 72 * r1 - machine type (passed as arg2 to initarm) 73 * r2 - Pointer to a tagged list or dtb image (phys addr) (passed as arg1 initarm) 74 * 75 * For both types of boot we gather up the args, put them in a struct arm_boot_params 76 * structure and pass that to initarm. 77 */ 78 .globl btext 79btext: 80ASENTRY_NP(_start) 81 STOP_UNWINDING /* Can't unwind into the bootloader! */ 82 83 mov r9, r0 /* 0 or boot mode from boot2 */ 84 mov r8, r1 /* Save Machine type */ 85 mov ip, r2 /* Save meta data */ 86 mov fp, r3 /* Future expansion */ 87 88 /* Make sure interrupts are disabled. */ 89 mrs r7, cpsr 90 orr r7, r7, #(I32_bit|F32_bit) 91 msr cpsr_c, r7 92 93#if defined (FLASHADDR) && defined(LOADERRAMADDR) 94 /* Check if we're running from flash. */ 95 ldr r7, =FLASHADDR 96 /* 97 * If we're running with MMU disabled, test against the 98 * physical address instead. 99 */ 100 mrc p15, 0, r2, c1, c0, 0 101 ands r2, r2, #CPU_CONTROL_MMU_ENABLE 102 ldreq r6, =PHYSADDR 103 ldrne r6, =LOADERRAMADDR 104 cmp r7, r6 105 bls flash_lower 106 cmp r7, pc 107 bhi from_ram 108 b do_copy 109 110flash_lower: 111 cmp r6, pc 112 bls from_ram 113do_copy: 114 ldr r7, =KERNBASE 115 adr r1, _start 116 ldr r0, Lreal_start 117 ldr r2, Lend 118 sub r2, r2, r0 119 sub r0, r0, r7 120 add r0, r0, r6 121 mov r4, r0 122 bl memcpy 123 ldr r0, Lram_offset 124 add pc, r4, r0 125Lram_offset: .word from_ram-_C_LABEL(_start) 126from_ram: 127 nop 128#endif 129 adr r7, Lunmapped 130 bic r7, r7, #0xf0000000 131 orr r7, r7, #PHYSADDR 132 133 134disable_mmu: 135 /* Disable MMU for a while */ 136 mrc p15, 0, r2, c1, c0, 0 137 bic r2, r2, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE |\ 138 CPU_CONTROL_WBUF_ENABLE) 139 bic r2, r2, #(CPU_CONTROL_IC_ENABLE) 140 bic r2, r2, #(CPU_CONTROL_BPRD_ENABLE) 141 mcr p15, 0, r2, c1, c0, 0 142 143 nop 144 nop 145 nop 146 mov pc, r7 147Lunmapped: 148 /* 149 * Build page table from scratch. 150 */ 151 152 /* Find the delta between VA and PA */ 153 adr r0, Lpagetable 154 ldr r1, [r0] 155 sub r2, r1, r0 156 /* At this point: r2 = VA - PA */ 157 158 /* 159 * Find the physical address of the table. After these two 160 * instructions: 161 * r1 = va(pagetable) 162 * 163 * r0 = va(pagetable) - (VA - PA) 164 * = va(pagetable) - VA + PA 165 * = pa(pagetable) 166 */ 167 ldr r1, [r0, #4] 168 sub r0, r1, r2 169 170#ifndef _ARM_ARCH_6 171 /* 172 * Some of the older ports (the various XScale, mostly) assume 173 * that the memory before the kernel is mapped, and use it for 174 * the various stacks, page tables, etc. For those CPUs, map the 175 * 64 first MB of RAM, as it used to be. 176 */ 177 /* 178 * Map PA == VA 179 */ 180 ldr r5, =PHYSADDR 181 mov r1, r5 182 mov r2, r5 183 /* Map 64MiB, preserved over calls to build_pagetables */ 184 mov r3, #64 185 bl build_pagetables 186 187 /* Create the kernel map to jump to */ 188 mov r1, r5 189 ldr r2, =(KERNBASE) 190 bl build_pagetables 191 ldr r5, =(KERNPHYSADDR) 192#else 193 /* 194 * Map PA == VA 195 */ 196 /* Find the start kernels load address */ 197 adr r5, _start 198 ldr r2, =(L1_S_OFFSET) 199 bic r5, r2 200 mov r1, r5 201 mov r2, r5 202 /* Map 64MiB, preserved over calls to build_pagetables */ 203 mov r3, #64 204 bl build_pagetables 205 206 /* Create the kernel map to jump to */ 207 mov r1, r5 208 ldr r2, =(KERNVIRTADDR) 209 bl build_pagetables 210#endif 211 212#if defined(SOCDEV_PA) && defined(SOCDEV_VA) 213 /* Create the custom map */ 214 ldr r1, =SOCDEV_PA 215 ldr r2, =SOCDEV_VA 216 bl build_pagetables 217#endif 218 219#if defined(SMP) 220 orr r0, r0, #2 /* Set TTB shared memory flag */ 221#endif 222 mcr p15, 0, r0, c2, c0, 0 /* Set TTB */ 223 mcr p15, 0, r0, c8, c7, 0 /* Flush TLB */ 224 225#if defined(CPU_ARM1136) || defined(CPU_ARM1176) || defined(CPU_CORTEXA) || defined(CPU_MV_PJ4B) || defined(CPU_KRAIT) 226 mov r0, #0 227 mcr p15, 0, r0, c13, c0, 1 /* Set ASID to 0 */ 228#endif 229 230 /* Set the Domain Access register. Very important! */ 231 mov r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT) 232 mcr p15, 0, r0, c3, c0, 0 233 /* 234 * Enable MMU. 235 * On armv6 enable extended page tables, and set alignment checking 236 * to modulo-4 (CPU_CONTROL_UNAL_ENABLE) for the ldrd/strd 237 * instructions emitted by clang. 238 */ 239 mrc p15, 0, r0, c1, c0, 0 240#ifdef _ARM_ARCH_6 241 orr r0, r0, #(CPU_CONTROL_V6_EXTPAGE | CPU_CONTROL_UNAL_ENABLE) 242 orr r0, r0, #(CPU_CONTROL_AFLT_ENABLE) 243 orr r0, r0, #(CPU_CONTROL_AF_ENABLE) 244#endif 245 orr r0, r0, #(CPU_CONTROL_MMU_ENABLE) 246 mcr p15, 0, r0, c1, c0, 0 247 nop 248 nop 249 nop 250 CPWAIT(r0) 251 252mmu_done: 253 nop 254 adr r1, .Lstart 255 ldmia r1, {r1, r2, sp} /* Set initial stack and */ 256 sub r2, r2, r1 /* get zero init data */ 257 mov r3, #0 258.L1: 259 str r3, [r1], #0x0004 /* get zero init data */ 260 subs r2, r2, #4 261 bgt .L1 262 ldr pc, .Lvirt_done 263 264virt_done: 265 mov r1, #28 /* loader info size is 28 bytes also second arg */ 266 subs sp, sp, r1 /* allocate arm_boot_params struct on stack */ 267 mov r0, sp /* loader info pointer is first arg */ 268 bic sp, sp, #7 /* align stack to 8 bytes */ 269 str r1, [r0] /* Store length of loader info */ 270 str r9, [r0, #4] /* Store r0 from boot loader */ 271 str r8, [r0, #8] /* Store r1 from boot loader */ 272 str ip, [r0, #12] /* store r2 from boot loader */ 273 str fp, [r0, #16] /* store r3 from boot loader */ 274 str r5, [r0, #20] /* store the physical address */ 275 adr r4, Lpagetable /* load the pagetable address */ 276 ldr r5, [r4, #4] 277 str r5, [r0, #24] /* store the pagetable address */ 278 mov fp, #0 /* trace back starts here */ 279 bl _C_LABEL(initarm) /* Off we go */ 280 281 /* init arm will return the new stack pointer. */ 282 mov sp, r0 283 284 bl _C_LABEL(mi_startup) /* call mi_startup()! */ 285 286 adr r0, .Lmainreturned 287 b _C_LABEL(panic) 288 /* NOTREACHED */ 289END(_start) 290 291/* 292 * Builds the page table 293 * r0 - The table base address 294 * r1 - The physical address (trashed) 295 * r2 - The virtual address (trashed) 296 * r3 - The number of 1MiB sections 297 * r4 - Trashed 298 * 299 * Addresses must be 1MiB aligned 300 */ 301build_pagetables: 302 /* Set the required page attributed */ 303 ldr r4, =(L1_TYPE_S|L1_S_C|L1_S_AP(AP_KRW)) 304#if defined(SMP) 305 orr r4, #(L1_SHARED) 306#endif 307 orr r1, r4 308 309 /* Move the virtual address to the correct bit location */ 310 lsr r2, #(L1_S_SHIFT - 2) 311 312 mov r4, r3 3131: 314 str r1, [r0, r2] 315 add r2, r2, #4 316 add r1, r1, #(L1_S_SIZE) 317 adds r4, r4, #-1 318 bhi 1b 319 320 RET 321 322Lpagetable: 323 .word . 324 .word pagetable 325 326Lvirtaddr: 327 .word KERNVIRTADDR 328Lphysaddr: 329 .word KERNPHYSADDR 330Lreal_start: 331 .word _start 332Lend: 333 .word _edata 334 335.Lstart: 336 .word _edata 337 .word _ebss 338 .word svcstk + INIT_ARM_STACK_SIZE 339 340.Lvirt_done: 341 .word virt_done 342 343.Lmainreturned: 344 .asciz "main() returned" 345 .align 0 346 347 .bss 348svcstk: 349 .space INIT_ARM_STACK_SIZE 350 351/* 352 * Memory for the initial pagetable. We are unable to place this in 353 * the bss as this will be cleared after the table is loaded. 354 */ 355 .section ".init_pagetable" 356 .align 14 /* 16KiB aligned */ 357pagetable: 358 .space L1_TABLE_SIZE 359 360 .text 361 .align 0 362 363.Lcpufuncs: 364 .word _C_LABEL(cpufuncs) 365 366#if defined(SMP) 367 368.Lmpvirt_done: 369 .word mpvirt_done 370Lstartup_pagetable_secondary: 371 .word temp_pagetable 372 373ASENTRY_NP(mpentry) 374 375 /* Make sure interrupts are disabled. */ 376 mrs r7, cpsr 377 orr r7, r7, #(I32_bit|F32_bit) 378 msr cpsr_c, r7 379 380 /* Disable MMU. It should be disabled already, but make sure. */ 381 mrc p15, 0, r2, c1, c0, 0 382 bic r2, r2, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE |\ 383 CPU_CONTROL_WBUF_ENABLE) 384 bic r2, r2, #(CPU_CONTROL_IC_ENABLE) 385 bic r2, r2, #(CPU_CONTROL_BPRD_ENABLE) 386 mcr p15, 0, r2, c1, c0, 0 387 nop 388 nop 389 nop 390 CPWAIT(r0) 391 392#if defined(ARM_MMU_V6) 393 bl armv6_idcache_inv_all /* Modifies r0 only */ 394#elif defined(ARM_MMU_V7) 395 bl armv7_idcache_inv_all /* Modifies r0-r3, ip */ 396#endif 397 398 ldr r0, Lstartup_pagetable_secondary 399 bic r0, r0, #0xf0000000 400 orr r0, r0, #PHYSADDR 401 ldr r0, [r0] 402 orr r0, r0, #2 /* Set TTB shared memory flag */ 403 mcr p15, 0, r0, c2, c0, 0 /* Set TTB */ 404 mcr p15, 0, r0, c8, c7, 0 /* Flush TLB */ 405 406 mov r0, #0 407 mcr p15, 0, r0, c13, c0, 1 /* Set ASID to 0 */ 408 409 /* Set the Domain Access register. Very important! */ 410 mov r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT) 411 mcr p15, 0, r0, c3, c0, 0 412 /* Enable MMU */ 413 mrc p15, 0, r0, c1, c0, 0 414 orr r0, r0, #CPU_CONTROL_V6_EXTPAGE 415 orr r0, r0, #CPU_CONTROL_AF_ENABLE 416 orr r0, r0, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE |\ 417 CPU_CONTROL_WBUF_ENABLE) 418 orr r0, r0, #(CPU_CONTROL_IC_ENABLE) 419 orr r0, r0, #(CPU_CONTROL_BPRD_ENABLE) 420 mcr p15, 0, r0, c1, c0, 0 421 nop 422 nop 423 nop 424 CPWAIT(r0) 425 426 adr r1, .Lstart 427 ldmia r1, {r1, r2, sp} /* Set initial stack and */ 428 mrc p15, 0, r0, c0, c0, 5 429 and r0, r0, #15 430 mov r1, #2048 431 mul r2, r1, r0 432 sub sp, sp, r2 433 str r1, [sp] 434 ldr pc, .Lmpvirt_done 435 436mpvirt_done: 437 438 mov fp, #0 /* trace back starts here */ 439 bl _C_LABEL(init_secondary) /* Off we go */ 440 441 adr r0, .Lmpreturned 442 b _C_LABEL(panic) 443 /* NOTREACHED */ 444 445.Lmpreturned: 446 .asciz "init_secondary() returned" 447 .align 0 448END(mpentry) 449#endif 450 451ENTRY_NP(cpu_halt) 452 mrs r2, cpsr 453 bic r2, r2, #(PSR_MODE) 454 orr r2, r2, #(PSR_SVC32_MODE) 455 orr r2, r2, #(I32_bit | F32_bit) 456 msr cpsr_fsxc, r2 457 458 ldr r4, .Lcpu_reset_address 459 ldr r4, [r4] 460 461 ldr r0, .Lcpufuncs 462 mov lr, pc 463 ldr pc, [r0, #CF_IDCACHE_WBINV_ALL] 464 mov lr, pc 465 ldr pc, [r0, #CF_L2CACHE_WBINV_ALL] 466 467 /* 468 * Load the cpu_reset_needs_v4_MMU_disable flag to determine if it's 469 * necessary. 470 */ 471 472 ldr r1, .Lcpu_reset_needs_v4_MMU_disable 473 ldr r1, [r1] 474 cmp r1, #0 475 mov r2, #0 476 477 /* 478 * MMU & IDC off, 32 bit program & data space 479 * Hurl ourselves into the ROM 480 */ 481 mov r0, #(CPU_CONTROL_32BP_ENABLE | CPU_CONTROL_32BD_ENABLE) 482 mcr 15, 0, r0, c1, c0, 0 483 mcrne 15, 0, r2, c8, c7, 0 /* nail I+D TLB on ARMv4 and greater */ 484 mov pc, r4 485 486 /* 487 * _cpu_reset_address contains the address to branch to, to complete 488 * the cpu reset after turning the MMU off 489 * This variable is provided by the hardware specific code 490 */ 491.Lcpu_reset_address: 492 .word _C_LABEL(cpu_reset_address) 493 494 /* 495 * cpu_reset_needs_v4_MMU_disable contains a flag that signals if the 496 * v4 MMU disable instruction needs executing... it is an illegal instruction 497 * on f.e. ARM6/7 that locks up the computer in an endless illegal 498 * instruction / data-abort / reset loop. 499 */ 500.Lcpu_reset_needs_v4_MMU_disable: 501 .word _C_LABEL(cpu_reset_needs_v4_MMU_disable) 502END(cpu_halt) 503 504 505/* 506 * setjump + longjmp 507 */ 508ENTRY(setjmp) 509 stmia r0, {r4-r14} 510 mov r0, #0x00000000 511 RET 512END(setjmp) 513 514ENTRY(longjmp) 515 ldmia r0, {r4-r14} 516 mov r0, #0x00000001 517 RET 518END(longjmp) 519 520 .data 521 .global _C_LABEL(esym) 522_C_LABEL(esym): .word _C_LABEL(end) 523 524ENTRY_NP(abort) 525 b _C_LABEL(abort) 526END(abort) 527 528ENTRY_NP(sigcode) 529 mov r0, sp 530 add r0, r0, #SIGF_UC 531 532 /* 533 * Call the sigreturn system call. 534 * 535 * We have to load r7 manually rather than using 536 * "ldr r7, =SYS_sigreturn" to ensure the value of szsigcode is 537 * correct. Using the alternative places esigcode at the address 538 * of the data rather than the address one past the data. 539 */ 540 541 ldr r7, [pc, #12] /* Load SYS_sigreturn */ 542 swi SYS_sigreturn 543 544 /* Well if that failed we better exit quick ! */ 545 546 ldr r7, [pc, #8] /* Load SYS_exit */ 547 swi SYS_exit 548 549 /* Branch back to retry SYS_sigreturn */ 550 b . - 16 551END(sigcode) 552 .word SYS_sigreturn 553 .word SYS_exit 554 555 .align 0 556 .global _C_LABEL(esigcode) 557 _C_LABEL(esigcode): 558 559 .data 560 .global szsigcode 561szsigcode: 562 .long esigcode-sigcode 563 564/* End of locore.S */ 565