locore-v4.S revision 265694
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: head/sys/arm/arm/locore.S 265694 2014-05-08 18:36:42Z ian $"); 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 */ 78ENTRY_NP(btext) 79ASENTRY_NP(_start) 80 STOP_UNWINDING /* Can't unwind into the bootloader! */ 81 82 mov r9, r0 /* 0 or boot mode from boot2 */ 83 mov r8, r1 /* Save Machine type */ 84 mov ip, r2 /* Save meta data */ 85 mov fp, r3 /* Future expantion */ 86 87 /* Make sure interrupts are disabled. */ 88 mrs r7, cpsr 89 orr r7, r7, #(I32_bit|F32_bit) 90 msr cpsr_c, r7 91 92#if defined (FLASHADDR) && defined(LOADERRAMADDR) 93 /* Check if we're running from flash. */ 94 ldr r7, =FLASHADDR 95 /* 96 * If we're running with MMU disabled, test against the 97 * physical address instead. 98 */ 99 mrc p15, 0, r2, c1, c0, 0 100 ands r2, r2, #CPU_CONTROL_MMU_ENABLE 101 ldreq r6, =PHYSADDR 102 ldrne r6, =LOADERRAMADDR 103 cmp r7, r6 104 bls flash_lower 105 cmp r7, pc 106 bhi from_ram 107 b do_copy 108 109flash_lower: 110 cmp r6, pc 111 bls from_ram 112do_copy: 113 ldr r7, =KERNBASE 114 adr r1, _start 115 ldr r0, Lreal_start 116 ldr r2, Lend 117 sub r2, r2, r0 118 sub r0, r0, r7 119 add r0, r0, r6 120 mov r4, r0 121 bl memcpy 122 ldr r0, Lram_offset 123 add pc, r4, r0 124Lram_offset: .word from_ram-_C_LABEL(_start) 125from_ram: 126 nop 127#endif 128 adr r7, Lunmapped 129 bic r7, r7, #0xf0000000 130 orr r7, r7, #PHYSADDR 131 132 133disable_mmu: 134 /* Disable MMU for a while */ 135 mrc p15, 0, r2, c1, c0, 0 136 bic r2, r2, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE |\ 137 CPU_CONTROL_WBUF_ENABLE) 138 bic r2, r2, #(CPU_CONTROL_IC_ENABLE) 139 bic r2, r2, #(CPU_CONTROL_BPRD_ENABLE) 140 mcr p15, 0, r2, c1, c0, 0 141 142 nop 143 nop 144 nop 145 mov pc, r7 146Lunmapped: 147 /* 148 * Build page table from scratch. 149 */ 150 151 /* Find the delta between VA and PA */ 152 adr r0, Lpagetable 153 ldr r1, [r0] 154 sub r2, r1, r0 155 /* At this point: r2 = VA - PA */ 156 157 /* 158 * Find the physical address of the table. After these two 159 * instructions: 160 * r1 = va(pagetable) 161 * 162 * r0 = va(pagetable) - (VA - PA) 163 * = va(pagetable) - VA + PA 164 * = pa(pagetable) 165 */ 166 ldr r1, [r0, #4] 167 sub r0, r1, r2 168 169 /* 170 * Map PA == VA 171 */ 172 /* Find the start kernels load address */ 173 adr r5, _start 174 ldr r2, =(L1_S_OFFSET) 175 bic r5, r2 176 mov r1, r5 177 mov r2, r5 178 /* Map 64MiB, preserved over calls to build_pagetables */ 179 mov r3, #64 180 bl build_pagetables 181 182 /* Create the kernel map to jump to */ 183 mov r1, r5 184 ldr r2, =(KERNVIRTADDR) 185 bl build_pagetables 186 187#if defined(SOCDEV_PA) && defined(SOCDEV_VA) 188 /* Create the custom map */ 189 ldr r1, =SOCDEV_PA 190 ldr r2, =SOCDEV_VA 191 bl build_pagetables 192#endif 193 194#if defined(SMP) 195 orr r0, r0, #2 /* Set TTB shared memory flag */ 196#endif 197 mcr p15, 0, r0, c2, c0, 0 /* Set TTB */ 198 mcr p15, 0, r0, c8, c7, 0 /* Flush TLB */ 199 200#if defined(CPU_ARM1136) || defined(CPU_ARM1176) || defined(CPU_CORTEXA) || defined(CPU_MV_PJ4B) || defined(CPU_KRAIT) 201 mov r0, #0 202 mcr p15, 0, r0, c13, c0, 1 /* Set ASID to 0 */ 203#endif 204 205 /* Set the Domain Access register. Very important! */ 206 mov r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT) 207 mcr p15, 0, r0, c3, c0, 0 208 /* 209 * Enable MMU. 210 * On armv6 enable extended page tables, and set alignment checking 211 * to modulo-4 (CPU_CONTROL_UNAL_ENABLE) for the ldrd/strd 212 * instructions emitted by clang. 213 */ 214 mrc p15, 0, r0, c1, c0, 0 215#ifdef _ARM_ARCH_6 216 orr r0, r0, #(CPU_CONTROL_V6_EXTPAGE | CPU_CONTROL_UNAL_ENABLE) 217 orr r0, r0, #(CPU_CONTROL_AFLT_ENABLE) 218 orr r0, r0, #(CPU_CONTROL_AF_ENABLE) 219#endif 220 orr r0, r0, #(CPU_CONTROL_MMU_ENABLE) 221 mcr p15, 0, r0, c1, c0, 0 222 nop 223 nop 224 nop 225 CPWAIT(r0) 226 227mmu_done: 228 nop 229 adr r1, .Lstart 230 ldmia r1, {r1, r2, sp} /* Set initial stack and */ 231 sub r2, r2, r1 /* get zero init data */ 232 mov r3, #0 233.L1: 234 str r3, [r1], #0x0004 /* get zero init data */ 235 subs r2, r2, #4 236 bgt .L1 237 ldr pc, .Lvirt_done 238 239virt_done: 240 mov r1, #28 /* loader info size is 28 bytes also second arg */ 241 subs sp, sp, r1 /* allocate arm_boot_params struct on stack */ 242 mov r0, sp /* loader info pointer is first arg */ 243 bic sp, sp, #7 /* align stack to 8 bytes */ 244 str r1, [r0] /* Store length of loader info */ 245 str r9, [r0, #4] /* Store r0 from boot loader */ 246 str r8, [r0, #8] /* Store r1 from boot loader */ 247 str ip, [r0, #12] /* store r2 from boot loader */ 248 str fp, [r0, #16] /* store r3 from boot loader */ 249 str r5, [r0, #20] /* store the physical address */ 250 adr r4, Lpagetable /* load the pagetable address */ 251 ldr r5, [r4, #4] 252 str r5, [r0, #24] /* store the pagetable address */ 253 mov fp, #0 /* trace back starts here */ 254 bl _C_LABEL(initarm) /* Off we go */ 255 256 /* init arm will return the new stack pointer. */ 257 mov sp, r0 258 259 bl _C_LABEL(mi_startup) /* call mi_startup()! */ 260 261 adr r0, .Lmainreturned 262 b _C_LABEL(panic) 263 /* NOTREACHED */ 264END(btext) 265END(_start) 266 267/* 268 * Builds the page table 269 * r0 - The table base address 270 * r1 - The physical address (trashed) 271 * r2 - The virtual address (trashed) 272 * r3 - The number of 1MiB sections 273 * r4 - Trashed 274 * 275 * Addresses must be 1MiB aligned 276 */ 277build_pagetables: 278 /* Set the required page attributed */ 279 ldr r4, =(L1_TYPE_S|L1_S_C|L1_S_AP(AP_KRW)) 280#if defined(SMP) 281 orr r4, #(L1_SHARED) 282#endif 283 orr r1, r4 284 285 /* Move the virtual address to the correct bit location */ 286 lsr r2, #(L1_S_SHIFT - 2) 287 288 mov r4, r3 2891: 290 str r1, [r0, r2] 291 add r2, r2, #4 292 add r1, r1, #(L1_S_SIZE) 293 adds r4, r4, #-1 294 bhi 1b 295 296 RET 297 298Lpagetable: 299 .word . 300 .word pagetable 301 302Lvirtaddr: 303 .word KERNVIRTADDR 304Lphysaddr: 305 .word KERNPHYSADDR 306Lreal_start: 307 .word _start 308Lend: 309 .word _edata 310 311#ifdef SMP 312Lstartup_pagetable_secondary: 313 .word temp_pagetable 314#endif 315 316.Lstart: 317 .word _edata 318 .word _ebss 319 .word svcstk + INIT_ARM_STACK_SIZE 320 321.Lvirt_done: 322 .word virt_done 323#if defined(SMP) 324.Lmpvirt_done: 325 .word mpvirt_done 326#endif 327 328.Lmainreturned: 329 .asciz "main() returned" 330 .align 0 331 332 .bss 333svcstk: 334 .space INIT_ARM_STACK_SIZE 335 336/* 337 * Memory for the initial pagetable. We are unable to place this in 338 * the bss as this will be cleared after the table is loaded. 339 */ 340 .section ".init_pagetable" 341 .align 14 /* 16KiB aligned */ 342pagetable: 343 .space L1_TABLE_SIZE 344 345 .text 346 .align 0 347 348.Lcpufuncs: 349 .word _C_LABEL(cpufuncs) 350 351#if defined(SMP) 352 353ASENTRY_NP(mpentry) 354 355 /* Make sure interrupts are disabled. */ 356 mrs r7, cpsr 357 orr r7, r7, #(I32_bit|F32_bit) 358 msr cpsr_c, r7 359 360 361 adr r7, Ltag 362 bic r7, r7, #0xf0000000 363 orr r7, r7, #PHYSADDR 364 365 /* Disable MMU for a while */ 366 mrc p15, 0, r2, c1, c0, 0 367 bic r2, r2, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE |\ 368 CPU_CONTROL_WBUF_ENABLE) 369 bic r2, r2, #(CPU_CONTROL_IC_ENABLE) 370 bic r2, r2, #(CPU_CONTROL_BPRD_ENABLE) 371 mcr p15, 0, r2, c1, c0, 0 372 373 nop 374 nop 375 nop 376 377Ltag: 378 ldr r0, Lstartup_pagetable_secondary 379 bic r0, r0, #0xf0000000 380 orr r0, r0, #PHYSADDR 381 ldr r0, [r0] 382#if defined(SMP) 383 orr r0, r0, #2 /* Set TTB shared memory flag */ 384#endif 385 mcr p15, 0, r0, c2, c0, 0 /* Set TTB */ 386 mcr p15, 0, r0, c8, c7, 0 /* Flush TLB */ 387 388#if defined(CPU_ARM1136) || defined(CPU_ARM1176) || defined(CPU_MV_PJ4B) || defined(CPU_CORTEXA) || defined(CPU_KRAIT) 389 mov r0, #0 390 mcr p15, 0, r0, c13, c0, 1 /* Set ASID to 0 */ 391#endif 392 393 /* Set the Domain Access register. Very important! */ 394 mov r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT) 395 mcr p15, 0, r0, c3, c0, 0 396 /* Enable MMU */ 397 mrc p15, 0, r0, c1, c0, 0 398#if defined(CPU_ARM1136) || defined(CPU_ARM1176) || defined(CPU_MV_PJ4B) || defined(CPU_CORTEXA) || defined(CPU_KRAIT) 399 orr r0, r0, #CPU_CONTROL_V6_EXTPAGE 400 orr r0, r0, #CPU_CONTROL_AF_ENABLE 401#endif 402 orr r0, r0, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE) 403 mcr p15, 0, r0, c1, c0, 0 404 nop 405 nop 406 nop 407 CPWAIT(r0) 408 409 adr r1, .Lstart 410 ldmia r1, {r1, r2, sp} /* Set initial stack and */ 411 mrc p15, 0, r0, c0, c0, 5 412 and r0, r0, #15 413 mov r1, #2048 414 mul r2, r1, r0 415 sub sp, sp, r2 416 str r1, [sp] 417 ldr pc, .Lmpvirt_done 418 419mpvirt_done: 420 421 mov fp, #0 /* trace back starts here */ 422 bl _C_LABEL(init_secondary) /* Off we go */ 423 424 adr r0, .Lmpreturned 425 b _C_LABEL(panic) 426 /* NOTREACHED */ 427 428.Lmpreturned: 429 .asciz "main() returned" 430 .align 0 431END(mpentry) 432#endif 433 434ENTRY_NP(cpu_halt) 435 mrs r2, cpsr 436 bic r2, r2, #(PSR_MODE) 437 orr r2, r2, #(PSR_SVC32_MODE) 438 orr r2, r2, #(I32_bit | F32_bit) 439 msr cpsr_fsxc, r2 440 441 ldr r4, .Lcpu_reset_address 442 ldr r4, [r4] 443 444 ldr r0, .Lcpufuncs 445 mov lr, pc 446 ldr pc, [r0, #CF_IDCACHE_WBINV_ALL] 447 mov lr, pc 448 ldr pc, [r0, #CF_L2CACHE_WBINV_ALL] 449 450 /* 451 * Load the cpu_reset_needs_v4_MMU_disable flag to determine if it's 452 * necessary. 453 */ 454 455 ldr r1, .Lcpu_reset_needs_v4_MMU_disable 456 ldr r1, [r1] 457 cmp r1, #0 458 mov r2, #0 459 460 /* 461 * MMU & IDC off, 32 bit program & data space 462 * Hurl ourselves into the ROM 463 */ 464 mov r0, #(CPU_CONTROL_32BP_ENABLE | CPU_CONTROL_32BD_ENABLE) 465 mcr 15, 0, r0, c1, c0, 0 466 mcrne 15, 0, r2, c8, c7, 0 /* nail I+D TLB on ARMv4 and greater */ 467 mov pc, r4 468 469 /* 470 * _cpu_reset_address contains the address to branch to, to complete 471 * the cpu reset after turning the MMU off 472 * This variable is provided by the hardware specific code 473 */ 474.Lcpu_reset_address: 475 .word _C_LABEL(cpu_reset_address) 476 477 /* 478 * cpu_reset_needs_v4_MMU_disable contains a flag that signals if the 479 * v4 MMU disable instruction needs executing... it is an illegal instruction 480 * on f.e. ARM6/7 that locks up the computer in an endless illegal 481 * instruction / data-abort / reset loop. 482 */ 483.Lcpu_reset_needs_v4_MMU_disable: 484 .word _C_LABEL(cpu_reset_needs_v4_MMU_disable) 485END(cpu_halt) 486 487 488/* 489 * setjump + longjmp 490 */ 491ENTRY(setjmp) 492 stmia r0, {r4-r14} 493 mov r0, #0x00000000 494 RET 495END(setjmp) 496 497ENTRY(longjmp) 498 ldmia r0, {r4-r14} 499 mov r0, #0x00000001 500 RET 501END(longjmp) 502 503 .data 504 .global _C_LABEL(esym) 505_C_LABEL(esym): .word _C_LABEL(end) 506 507ENTRY_NP(abort) 508 b _C_LABEL(abort) 509END(abort) 510 511ENTRY_NP(sigcode) 512 mov r0, sp 513 add r0, r0, #SIGF_UC 514 515 /* 516 * Call the sigreturn system call. 517 * 518 * We have to load r7 manually rather than using 519 * "ldr r7, =SYS_sigreturn" to ensure the value of szsigcode is 520 * correct. Using the alternative places esigcode at the address 521 * of the data rather than the address one past the data. 522 */ 523 524 ldr r7, [pc, #12] /* Load SYS_sigreturn */ 525 swi SYS_sigreturn 526 527 /* Well if that failed we better exit quick ! */ 528 529 ldr r7, [pc, #8] /* Load SYS_exit */ 530 swi SYS_exit 531 532 /* Branch back to retry SYS_sigreturn */ 533 b . - 16 534 535 .word SYS_sigreturn 536 .word SYS_exit 537 538 .align 0 539 .global _C_LABEL(esigcode) 540 _C_LABEL(esigcode): 541 542 .data 543 .global szsigcode 544szsigcode: 545 .long esigcode-sigcode 546END(sigcode) 547/* End of locore.S */ 548