1/* 2 * linux/arch/arm/kernel/head.S 3 * 4 * Copyright (C) 1994-2002 Russell King 5 * Copyright (c) 2003 ARM Limited 6 * All Rights Reserved 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * Kernel startup code for all 32-bit CPUs 13 */ 14#include <linux/linkage.h> 15#include <linux/init.h> 16 17#include <asm/assembler.h> 18#include <asm/cp15.h> 19#include <asm/domain.h> 20#include <asm/ptrace.h> 21#include <asm/asm-offsets.h> 22#include <asm/memory.h> 23#include <asm/thread_info.h> 24#include <asm/pgtable.h> 25 26#if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING) 27#include CONFIG_DEBUG_LL_INCLUDE 28#endif 29 30/* 31 * swapper_pg_dir is the virtual address of the initial page table. 32 * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must 33 * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect 34 * the least significant 16 bits to be 0x8000, but we could probably 35 * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000. 36 */ 37#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET) 38#if (KERNEL_RAM_VADDR & 0xffff) != 0x8000 39#error KERNEL_RAM_VADDR must start at 0xXXXX8000 40#endif 41 42#ifdef CONFIG_ARM_LPAE 43 /* LPAE requires an additional page for the PGD */ 44#define PG_DIR_SIZE 0x5000 45#define PMD_ORDER 3 46#else 47#define PG_DIR_SIZE 0x4000 48#define PMD_ORDER 2 49#endif 50 51 .globl swapper_pg_dir 52 .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE 53 54 .macro pgtbl, rd, phys 55 add \rd, \phys, #TEXT_OFFSET 56 sub \rd, \rd, #PG_DIR_SIZE 57 .endm 58 59/* 60 * Kernel startup entry point. 61 * --------------------------- 62 * 63 * This is normally called from the decompressor code. The requirements 64 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, 65 * r1 = machine nr, r2 = atags or dtb pointer. 66 * 67 * This code is mostly position independent, so if you link the kernel at 68 * 0xc0008000, you call this at __pa(0xc0008000). 69 * 70 * See linux/arch/arm/tools/mach-types for the complete list of machine 71 * numbers for r1. 72 * 73 * We're trying to keep crap to a minimum; DO NOT add any machine specific 74 * crap here - that's what the boot loader (or in extreme, well justified 75 * circumstances, zImage) is for. 76 */ 77 .arm 78 79 __HEAD 80ENTRY(stext) 81 ARM_BE8(setend be ) @ ensure we are in BE8 mode 82 83 THUMB( badr r9, 1f ) @ Kernel is always entered in ARM. 84 THUMB( bx r9 ) @ If this is a Thumb-2 kernel, 85 THUMB( .thumb ) @ switch to Thumb now. 86 THUMB(1: ) 87 88#ifdef CONFIG_ARM_VIRT_EXT 89 bl __hyp_stub_install 90#endif 91 @ ensure svc mode and all interrupts masked 92 safe_svcmode_maskall r9 93 94 mrc p15, 0, r9, c0, c0 @ get processor id 95 bl __lookup_processor_type @ r5=procinfo r9=cpuid 96 movs r10, r5 @ invalid processor (r5=0)? 97 THUMB( it eq ) @ force fixup-able long branch encoding 98 beq __error_p @ yes, error 'p' 99 100#ifdef CONFIG_ARM_LPAE 101 mrc p15, 0, r3, c0, c1, 4 @ read ID_MMFR0 102 and r3, r3, #0xf @ extract VMSA support 103 cmp r3, #5 @ long-descriptor translation table format? 104 THUMB( it lo ) @ force fixup-able long branch encoding 105 blo __error_lpae @ only classic page table format 106#endif 107 108#ifndef CONFIG_XIP_KERNEL 109 adr r3, 2f 110 ldmia r3, {r4, r8} 111 sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET) 112 add r8, r8, r4 @ PHYS_OFFSET 113#else 114 ldr r8, =PLAT_PHYS_OFFSET @ always constant in this case 115#endif 116 117 /* 118 * r1 = machine no, r2 = atags or dtb, 119 * r8 = phys_offset, r9 = cpuid, r10 = procinfo 120 */ 121 bl __vet_atags 122#ifdef CONFIG_SMP_ON_UP 123 bl __fixup_smp 124#endif 125#ifdef CONFIG_ARM_PATCH_PHYS_VIRT 126 bl __fixup_pv_table 127#endif 128 bl __create_page_tables 129 130 /* 131 * The following calls CPU specific code in a position independent 132 * manner. See arch/arm/mm/proc-*.S for details. r10 = base of 133 * xxx_proc_info structure selected by __lookup_processor_type 134 * above. 135 * 136 * The processor init function will be called with: 137 * r1 - machine type 138 * r2 - boot data (atags/dt) pointer 139 * r4 - translation table base (low word) 140 * r5 - translation table base (high word, if LPAE) 141 * r8 - translation table base 1 (pfn if LPAE) 142 * r9 - cpuid 143 * r13 - virtual address for __enable_mmu -> __turn_mmu_on 144 * 145 * On return, the CPU will be ready for the MMU to be turned on, 146 * r0 will hold the CPU control register value, r1, r2, r4, and 147 * r9 will be preserved. r5 will also be preserved if LPAE. 148 */ 149 ldr r13, =__mmap_switched @ address to jump to after 150 @ mmu has been enabled 151 badr lr, 1f @ return (PIC) address 152#ifdef CONFIG_ARM_LPAE 153 mov r5, #0 @ high TTBR0 154 mov r8, r4, lsr #12 @ TTBR1 is swapper_pg_dir pfn 155#else 156 mov r8, r4 @ set TTBR1 to swapper_pg_dir 157#endif 158 ldr r12, [r10, #PROCINFO_INITFUNC] 159 add r12, r12, r10 160 ret r12 1611: b __enable_mmu 162ENDPROC(stext) 163 .ltorg 164#ifndef CONFIG_XIP_KERNEL 1652: .long . 166 .long PAGE_OFFSET 167#endif 168 169/* 170 * Setup the initial page tables. We only setup the barest 171 * amount which are required to get the kernel running, which 172 * generally means mapping in the kernel code. 173 * 174 * r8 = phys_offset, r9 = cpuid, r10 = procinfo 175 * 176 * Returns: 177 * r0, r3, r5-r7 corrupted 178 * r4 = physical page table address 179 */ 180__create_page_tables: 181 pgtbl r4, r8 @ page table address 182 183 /* 184 * Clear the swapper page table 185 */ 186 mov r0, r4 187 mov r3, #0 188 add r6, r0, #PG_DIR_SIZE 1891: str r3, [r0], #4 190 str r3, [r0], #4 191 str r3, [r0], #4 192 str r3, [r0], #4 193 teq r0, r6 194 bne 1b 195 196#ifdef CONFIG_ARM_LPAE 197 /* 198 * Build the PGD table (first level) to point to the PMD table. A PGD 199 * entry is 64-bit wide. 200 */ 201 mov r0, r4 202 add r3, r4, #0x1000 @ first PMD table address 203 orr r3, r3, #3 @ PGD block type 204 mov r6, #4 @ PTRS_PER_PGD 205 mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER 2061: 207#ifdef CONFIG_CPU_ENDIAN_BE8 208 str r7, [r0], #4 @ set top PGD entry bits 209 str r3, [r0], #4 @ set bottom PGD entry bits 210#else 211 str r3, [r0], #4 @ set bottom PGD entry bits 212 str r7, [r0], #4 @ set top PGD entry bits 213#endif 214 add r3, r3, #0x1000 @ next PMD table 215 subs r6, r6, #1 216 bne 1b 217 218 add r4, r4, #0x1000 @ point to the PMD tables 219#ifdef CONFIG_CPU_ENDIAN_BE8 220 add r4, r4, #4 @ we only write the bottom word 221#endif 222#endif 223 224 ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags 225 226 /* 227 * Create identity mapping to cater for __enable_mmu. 228 * This identity mapping will be removed by paging_init(). 229 */ 230 adr r0, __turn_mmu_on_loc 231 ldmia r0, {r3, r5, r6} 232 sub r0, r0, r3 @ virt->phys offset 233 add r5, r5, r0 @ phys __turn_mmu_on 234 add r6, r6, r0 @ phys __turn_mmu_on_end 235 mov r5, r5, lsr #SECTION_SHIFT 236 mov r6, r6, lsr #SECTION_SHIFT 237 2381: orr r3, r7, r5, lsl #SECTION_SHIFT @ flags + kernel base 239 str r3, [r4, r5, lsl #PMD_ORDER] @ identity mapping 240 cmp r5, r6 241 addlo r5, r5, #1 @ next section 242 blo 1b 243 244 /* 245 * Map our RAM from the start to the end of the kernel .bss section. 246 */ 247 add r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER) 248 ldr r6, =(_end - 1) 249 orr r3, r8, r7 250 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) 2511: str r3, [r0], #1 << PMD_ORDER 252 add r3, r3, #1 << SECTION_SHIFT 253 cmp r0, r6 254 bls 1b 255 256#ifdef CONFIG_XIP_KERNEL 257 /* 258 * Map the kernel image separately as it is not located in RAM. 259 */ 260#define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) 261 mov r3, pc 262 mov r3, r3, lsr #SECTION_SHIFT 263 orr r3, r7, r3, lsl #SECTION_SHIFT 264 add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER) 265 str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]! 266 ldr r6, =(_edata_loc - 1) 267 add r0, r0, #1 << PMD_ORDER 268 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) 2691: cmp r0, r6 270 add r3, r3, #1 << SECTION_SHIFT 271 strls r3, [r0], #1 << PMD_ORDER 272 bls 1b 273#endif 274 275 /* 276 * Then map boot params address in r2 if specified. 277 * We map 2 sections in case the ATAGs/DTB crosses a section boundary. 278 */ 279 mov r0, r2, lsr #SECTION_SHIFT 280 movs r0, r0, lsl #SECTION_SHIFT 281 subne r3, r0, r8 282 addne r3, r3, #PAGE_OFFSET 283 addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER) 284 orrne r6, r7, r0 285 strne r6, [r3], #1 << PMD_ORDER 286 addne r6, r6, #1 << SECTION_SHIFT 287 strne r6, [r3] 288 289#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8) 290 sub r4, r4, #4 @ Fixup page table pointer 291 @ for 64-bit descriptors 292#endif 293 294#ifdef CONFIG_DEBUG_LL 295#if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING) 296 /* 297 * Map in IO space for serial debugging. 298 * This allows debug messages to be output 299 * via a serial console before paging_init. 300 */ 301 addruart r7, r3, r0 302 303 mov r3, r3, lsr #SECTION_SHIFT 304 mov r3, r3, lsl #PMD_ORDER 305 306 add r0, r4, r3 307 mov r3, r7, lsr #SECTION_SHIFT 308 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags 309 orr r3, r7, r3, lsl #SECTION_SHIFT 310#ifdef CONFIG_ARM_LPAE 311 mov r7, #1 << (54 - 32) @ XN 312#ifdef CONFIG_CPU_ENDIAN_BE8 313 str r7, [r0], #4 314 str r3, [r0], #4 315#else 316 str r3, [r0], #4 317 str r7, [r0], #4 318#endif 319#else 320 orr r3, r3, #PMD_SECT_XN 321 str r3, [r0], #4 322#endif 323 324#else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */ 325 /* we don't need any serial debugging mappings */ 326 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags 327#endif 328 329#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS) 330 /* 331 * If we're using the NetWinder or CATS, we also need to map 332 * in the 16550-type serial port for the debug messages 333 */ 334 add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER) 335 orr r3, r7, #0x7c000000 336 str r3, [r0] 337#endif 338#ifdef CONFIG_ARCH_RPC 339 /* 340 * Map in screen at 0x02000000 & SCREEN2_BASE 341 * Similar reasons here - for debug. This is 342 * only for Acorn RiscPC architectures. 343 */ 344 add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER) 345 orr r3, r7, #0x02000000 346 str r3, [r0] 347 add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER) 348 str r3, [r0] 349#endif 350#endif 351#ifdef CONFIG_ARM_LPAE 352 sub r4, r4, #0x1000 @ point to the PGD table 353#endif 354 ret lr 355ENDPROC(__create_page_tables) 356 .ltorg 357 .align 358__turn_mmu_on_loc: 359 .long . 360 .long __turn_mmu_on 361 .long __turn_mmu_on_end 362 363#if defined(CONFIG_SMP) 364 .text 365 .arm 366ENTRY(secondary_startup_arm) 367 THUMB( badr r9, 1f ) @ Kernel is entered in ARM. 368 THUMB( bx r9 ) @ If this is a Thumb-2 kernel, 369 THUMB( .thumb ) @ switch to Thumb now. 370 THUMB(1: ) 371ENTRY(secondary_startup) 372 /* 373 * Common entry point for secondary CPUs. 374 * 375 * Ensure that we're in SVC mode, and IRQs are disabled. Lookup 376 * the processor type - there is no need to check the machine type 377 * as it has already been validated by the primary processor. 378 */ 379 380 ARM_BE8(setend be) @ ensure we are in BE8 mode 381 382#ifdef CONFIG_ARM_VIRT_EXT 383 bl __hyp_stub_install_secondary 384#endif 385 safe_svcmode_maskall r9 386 387 mrc p15, 0, r9, c0, c0 @ get processor id 388 bl __lookup_processor_type 389 movs r10, r5 @ invalid processor? 390 moveq r0, #'p' @ yes, error 'p' 391 THUMB( it eq ) @ force fixup-able long branch encoding 392 beq __error_p 393 394 /* 395 * Use the page tables supplied from __cpu_up. 396 */ 397 adr r4, __secondary_data 398 ldmia r4, {r5, r7, r12} @ address to jump to after 399 sub lr, r4, r5 @ mmu has been enabled 400 add r3, r7, lr 401 ldrd r4, [r3, #0] @ get secondary_data.pgdir 402ARM_BE8(eor r4, r4, r5) @ Swap r5 and r4 in BE: 403ARM_BE8(eor r5, r4, r5) @ it can be done in 3 steps 404ARM_BE8(eor r4, r4, r5) @ without using a temp reg. 405 ldr r8, [r3, #8] @ get secondary_data.swapper_pg_dir 406 badr lr, __enable_mmu @ return address 407 mov r13, r12 @ __secondary_switched address 408 ldr r12, [r10, #PROCINFO_INITFUNC] 409 add r12, r12, r10 @ initialise processor 410 @ (return control reg) 411 ret r12 412ENDPROC(secondary_startup) 413ENDPROC(secondary_startup_arm) 414 415 /* 416 * r6 = &secondary_data 417 */ 418ENTRY(__secondary_switched) 419 ldr sp, [r7, #12] @ get secondary_data.stack 420 mov fp, #0 421 b secondary_start_kernel 422ENDPROC(__secondary_switched) 423 424 .align 425 426 .type __secondary_data, %object 427__secondary_data: 428 .long . 429 .long secondary_data 430 .long __secondary_switched 431#endif /* defined(CONFIG_SMP) */ 432 433 434 435/* 436 * Setup common bits before finally enabling the MMU. Essentially 437 * this is just loading the page table pointer and domain access 438 * registers. All these registers need to be preserved by the 439 * processor setup function (or set in the case of r0) 440 * 441 * r0 = cp#15 control register 442 * r1 = machine ID 443 * r2 = atags or dtb pointer 444 * r4 = TTBR pointer (low word) 445 * r5 = TTBR pointer (high word if LPAE) 446 * r9 = processor ID 447 * r13 = *virtual* address to jump to upon completion 448 */ 449__enable_mmu: 450#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6 451 orr r0, r0, #CR_A 452#else 453 bic r0, r0, #CR_A 454#endif 455#ifdef CONFIG_CPU_DCACHE_DISABLE 456 bic r0, r0, #CR_C 457#endif 458#ifdef CONFIG_CPU_BPREDICT_DISABLE 459 bic r0, r0, #CR_Z 460#endif 461#ifdef CONFIG_CPU_ICACHE_DISABLE 462 bic r0, r0, #CR_I 463#endif 464#ifdef CONFIG_ARM_LPAE 465 mcrr p15, 0, r4, r5, c2 @ load TTBR0 466#else 467 mov r5, #DACR_INIT 468 mcr p15, 0, r5, c3, c0, 0 @ load domain access register 469 mcr p15, 0, r4, c2, c0, 0 @ load page table pointer 470#endif 471 b __turn_mmu_on 472ENDPROC(__enable_mmu) 473 474/* 475 * Enable the MMU. This completely changes the structure of the visible 476 * memory space. You will not be able to trace execution through this. 477 * If you have an enquiry about this, *please* check the linux-arm-kernel 478 * mailing list archives BEFORE sending another post to the list. 479 * 480 * r0 = cp#15 control register 481 * r1 = machine ID 482 * r2 = atags or dtb pointer 483 * r9 = processor ID 484 * r13 = *virtual* address to jump to upon completion 485 * 486 * other registers depend on the function called upon completion 487 */ 488 .align 5 489 .pushsection .idmap.text, "ax" 490ENTRY(__turn_mmu_on) 491 mov r0, r0 492 instr_sync 493 mcr p15, 0, r0, c1, c0, 0 @ write control reg 494 mrc p15, 0, r3, c0, c0, 0 @ read id reg 495 instr_sync 496 mov r3, r3 497 mov r3, r13 498 ret r3 499__turn_mmu_on_end: 500ENDPROC(__turn_mmu_on) 501 .popsection 502 503 504#ifdef CONFIG_SMP_ON_UP 505 __HEAD 506__fixup_smp: 507 and r3, r9, #0x000f0000 @ architecture version 508 teq r3, #0x000f0000 @ CPU ID supported? 509 bne __fixup_smp_on_up @ no, assume UP 510 511 bic r3, r9, #0x00ff0000 512 bic r3, r3, #0x0000000f @ mask 0xff00fff0 513 mov r4, #0x41000000 514 orr r4, r4, #0x0000b000 515 orr r4, r4, #0x00000020 @ val 0x4100b020 516 teq r3, r4 @ ARM 11MPCore? 517 reteq lr @ yes, assume SMP 518 519 mrc p15, 0, r0, c0, c0, 5 @ read MPIDR 520 and r0, r0, #0xc0000000 @ multiprocessing extensions and 521 teq r0, #0x80000000 @ not part of a uniprocessor system? 522 bne __fixup_smp_on_up @ no, assume UP 523 524 @ Core indicates it is SMP. Check for Aegis SOC where a single 525 @ Cortex-A9 CPU is present but SMP operations fault. 526 mov r4, #0x41000000 527 orr r4, r4, #0x0000c000 528 orr r4, r4, #0x00000090 529 teq r3, r4 @ Check for ARM Cortex-A9 530 retne lr @ Not ARM Cortex-A9, 531 532 @ If a future SoC *does* use 0x0 as the PERIPH_BASE, then the 533 @ below address check will need to be #ifdef'd or equivalent 534 @ for the Aegis platform. 535 mrc p15, 4, r0, c15, c0 @ get SCU base address 536 teq r0, #0x0 @ '0' on actual UP A9 hardware 537 beq __fixup_smp_on_up @ So its an A9 UP 538 ldr r0, [r0, #4] @ read SCU Config 539ARM_BE8(rev r0, r0) @ byteswap if big endian 540 and r0, r0, #0x3 @ number of CPUs 541 teq r0, #0x0 @ is 1? 542 retne lr 543 544__fixup_smp_on_up: 545 adr r0, 1f 546 ldmia r0, {r3 - r5} 547 sub r3, r0, r3 548 add r4, r4, r3 549 add r5, r5, r3 550 b __do_fixup_smp_on_up 551ENDPROC(__fixup_smp) 552 553 .align 5541: .word . 555 .word __smpalt_begin 556 .word __smpalt_end 557 558 .pushsection .data 559 .globl smp_on_up 560smp_on_up: 561 ALT_SMP(.long 1) 562 ALT_UP(.long 0) 563 .popsection 564#endif 565 566 .text 567__do_fixup_smp_on_up: 568 cmp r4, r5 569 reths lr 570 ldmia r4!, {r0, r6} 571 ARM( str r6, [r0, r3] ) 572 THUMB( add r0, r0, r3 ) 573#ifdef __ARMEB__ 574 THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian. 575#endif 576 THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords 577 THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3. 578 THUMB( strh r6, [r0] ) 579 b __do_fixup_smp_on_up 580ENDPROC(__do_fixup_smp_on_up) 581 582ENTRY(fixup_smp) 583 stmfd sp!, {r4 - r6, lr} 584 mov r4, r0 585 add r5, r0, r1 586 mov r3, #0 587 bl __do_fixup_smp_on_up 588 ldmfd sp!, {r4 - r6, pc} 589ENDPROC(fixup_smp) 590 591#ifdef __ARMEB__ 592#define LOW_OFFSET 0x4 593#define HIGH_OFFSET 0x0 594#else 595#define LOW_OFFSET 0x0 596#define HIGH_OFFSET 0x4 597#endif 598 599#ifdef CONFIG_ARM_PATCH_PHYS_VIRT 600 601/* __fixup_pv_table - patch the stub instructions with the delta between 602 * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and 603 * can be expressed by an immediate shifter operand. The stub instruction 604 * has a form of '(add|sub) rd, rn, #imm'. 605 */ 606 __HEAD 607__fixup_pv_table: 608 adr r0, 1f 609 ldmia r0, {r3-r7} 610 mvn ip, #0 611 subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET 612 add r4, r4, r3 @ adjust table start address 613 add r5, r5, r3 @ adjust table end address 614 add r6, r6, r3 @ adjust __pv_phys_pfn_offset address 615 add r7, r7, r3 @ adjust __pv_offset address 616 mov r0, r8, lsr #PAGE_SHIFT @ convert to PFN 617 str r0, [r6] @ save computed PHYS_OFFSET to __pv_phys_pfn_offset 618 strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits 619 mov r6, r3, lsr #24 @ constant for add/sub instructions 620 teq r3, r6, lsl #24 @ must be 16MiB aligned 621THUMB( it ne @ cross section branch ) 622 bne __error 623 str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits 624 b __fixup_a_pv_table 625ENDPROC(__fixup_pv_table) 626 627 .align 6281: .long . 629 .long __pv_table_begin 630 .long __pv_table_end 6312: .long __pv_phys_pfn_offset 632 .long __pv_offset 633 634 .text 635__fixup_a_pv_table: 636 adr r0, 3f 637 ldr r6, [r0] 638 add r6, r6, r3 639 ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word 640 ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word 641 mov r6, r6, lsr #24 642 cmn r0, #1 643#ifdef CONFIG_THUMB2_KERNEL 644 moveq r0, #0x200000 @ set bit 21, mov to mvn instruction 645 lsls r6, #24 646 beq 2f 647 clz r7, r6 648 lsr r6, #24 649 lsl r6, r7 650 bic r6, #0x0080 651 lsrs r7, #1 652 orrcs r6, #0x0080 653 orr r6, r6, r7, lsl #12 654 orr r6, #0x4000 655 b 2f 6561: add r7, r3 657 ldrh ip, [r7, #2] 658ARM_BE8(rev16 ip, ip) 659 tst ip, #0x4000 660 and ip, #0x8f00 661 orrne ip, r6 @ mask in offset bits 31-24 662 orreq ip, r0 @ mask in offset bits 7-0 663ARM_BE8(rev16 ip, ip) 664 strh ip, [r7, #2] 665 bne 2f 666 ldrh ip, [r7] 667ARM_BE8(rev16 ip, ip) 668 bic ip, #0x20 669 orr ip, ip, r0, lsr #16 670ARM_BE8(rev16 ip, ip) 671 strh ip, [r7] 6722: cmp r4, r5 673 ldrcc r7, [r4], #4 @ use branch for delay slot 674 bcc 1b 675 bx lr 676#else 677#ifdef CONFIG_CPU_ENDIAN_BE8 678 moveq r0, #0x00004000 @ set bit 22, mov to mvn instruction 679#else 680 moveq r0, #0x400000 @ set bit 22, mov to mvn instruction 681#endif 682 b 2f 6831: ldr ip, [r7, r3] 684#ifdef CONFIG_CPU_ENDIAN_BE8 685 @ in BE8, we load data in BE, but instructions still in LE 686 bic ip, ip, #0xff000000 687 tst ip, #0x000f0000 @ check the rotation field 688 orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24 689 biceq ip, ip, #0x00004000 @ clear bit 22 690 orreq ip, ip, r0 @ mask in offset bits 7-0 691#else 692 bic ip, ip, #0x000000ff 693 tst ip, #0xf00 @ check the rotation field 694 orrne ip, ip, r6 @ mask in offset bits 31-24 695 biceq ip, ip, #0x400000 @ clear bit 22 696 orreq ip, ip, r0 @ mask in offset bits 7-0 697#endif 698 str ip, [r7, r3] 6992: cmp r4, r5 700 ldrcc r7, [r4], #4 @ use branch for delay slot 701 bcc 1b 702 ret lr 703#endif 704ENDPROC(__fixup_a_pv_table) 705 706 .align 7073: .long __pv_offset 708 709ENTRY(fixup_pv_table) 710 stmfd sp!, {r4 - r7, lr} 711 mov r3, #0 @ no offset 712 mov r4, r0 @ r0 = table start 713 add r5, r0, r1 @ r1 = table size 714 bl __fixup_a_pv_table 715 ldmfd sp!, {r4 - r7, pc} 716ENDPROC(fixup_pv_table) 717 718 .data 719 .globl __pv_phys_pfn_offset 720 .type __pv_phys_pfn_offset, %object 721__pv_phys_pfn_offset: 722 .word 0 723 .size __pv_phys_pfn_offset, . -__pv_phys_pfn_offset 724 725 .globl __pv_offset 726 .type __pv_offset, %object 727__pv_offset: 728 .quad 0 729 .size __pv_offset, . -__pv_offset 730#endif 731 732#include "head-common.S" 733