1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * linux/boot/head.S 4 * 5 * Copyright (C) 1991, 1992, 1993 Linus Torvalds 6 */ 7 8/* 9 * head.S contains the 32-bit startup code. 10 * 11 * NOTE!!! Startup happens at absolute address 0x00001000, which is also where 12 * the page directory will exist. The startup code will be overwritten by 13 * the page directory. [According to comments etc elsewhere on a compressed 14 * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] 15 * 16 * Page 0 is deliberately kept safe, since System Management Mode code in 17 * laptops may need to access the BIOS data stored there. This is also 18 * useful for future device drivers that either access the BIOS via VM86 19 * mode. 20 */ 21 22/* 23 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 24 */ 25 .code32 26 .text 27 28#include <linux/init.h> 29#include <linux/linkage.h> 30#include <asm/segment.h> 31#include <asm/boot.h> 32#include <asm/msr.h> 33#include <asm/processor-flags.h> 34#include <asm/asm-offsets.h> 35#include <asm/bootparam.h> 36#include "pgtable.h" 37 38/* 39 * Locally defined symbols should be marked hidden: 40 */ 41 .hidden _bss 42 .hidden _ebss 43 .hidden _got 44 .hidden _egot 45 .hidden _end 46 47 __HEAD 48 .code32 49SYM_FUNC_START(startup_32) 50 /* 51 * 32bit entry is 0 and it is ABI so immutable! 52 * If we come here directly from a bootloader, 53 * kernel(text+data+bss+brk) ramdisk, zero_page, command line 54 * all need to be under the 4G limit. 55 */ 56 cld 57 cli 58 59/* 60 * Calculate the delta between where we were compiled to run 61 * at and where we were actually loaded at. This can only be done 62 * with a short local call on x86. Nothing else will tell us what 63 * address we are running at. The reserved chunk of the real-mode 64 * data at 0x1e4 (defined as a scratch field) are used as the stack 65 * for this calculation. Only 4 bytes are needed. 66 */ 67 leal (BP_scratch+4)(%esi), %esp 68 call 1f 691: popl %ebp 70 subl $1b, %ebp 71 72 /* Load new GDT with the 64bit segments using 32bit descriptor */ 73 leal gdt(%ebp), %eax 74 movl %eax, 2(%eax) 75 lgdt (%eax) 76 77 /* Load segment registers with our descriptors */ 78 movl $__BOOT_DS, %eax 79 movl %eax, %ds 80 movl %eax, %es 81 movl %eax, %fs 82 movl %eax, %gs 83 movl %eax, %ss 84 85/* setup a stack and make sure cpu supports long mode. */ 86 leal boot_stack_end(%ebp), %esp 87 88 call verify_cpu 89 testl %eax, %eax 90 jnz .Lno_longmode 91 92/* 93 * Compute the delta between where we were compiled to run at 94 * and where the code will actually run at. 95 * 96 * %ebp contains the address we are loaded at by the boot loader and %ebx 97 * contains the address where we should move the kernel image temporarily 98 * for safe in-place decompression. 99 */ 100 101#ifdef CONFIG_RELOCATABLE 102 movl %ebp, %ebx 103 104#ifdef CONFIG_EFI_STUB 105/* 106 * If we were loaded via the EFI LoadImage service, startup_32 will be at an 107 * offset to the start of the space allocated for the image. efi_pe_entry will 108 * set up image_offset to tell us where the image actually starts, so that we 109 * can use the full available buffer. 110 * image_offset = startup_32 - image_base 111 * Otherwise image_offset will be zero and has no effect on the calculations. 112 */ 113 subl image_offset(%ebp), %ebx 114#endif 115 116 movl BP_kernel_alignment(%esi), %eax 117 decl %eax 118 addl %eax, %ebx 119 notl %eax 120 andl %eax, %ebx 121 cmpl $LOAD_PHYSICAL_ADDR, %ebx 122 jae 1f 123#endif 124 movl $LOAD_PHYSICAL_ADDR, %ebx 1251: 126 127 /* Target address to relocate to for decompression */ 128 addl BP_init_size(%esi), %ebx 129 subl $_end, %ebx 130 131/* 132 * Prepare for entering 64 bit mode 133 */ 134 135 /* Enable PAE mode */ 136 movl %cr4, %eax 137 orl $X86_CR4_PAE, %eax 138 movl %eax, %cr4 139 140 /* 141 * Build early 4G boot pagetable 142 */ 143 /* 144 * If SEV is active then set the encryption mask in the page tables. 145 * This will insure that when the kernel is copied and decompressed 146 * it will be done so encrypted. 147 */ 148 call get_sev_encryption_bit 149 xorl %edx, %edx 150 testl %eax, %eax 151 jz 1f 152 subl $32, %eax /* Encryption bit is always above bit 31 */ 153 bts %eax, %edx /* Set encryption mask for page tables */ 1541: 155 156 /* Initialize Page tables to 0 */ 157 leal pgtable(%ebx), %edi 158 xorl %eax, %eax 159 movl $(BOOT_INIT_PGT_SIZE/4), %ecx 160 rep stosl 161 162 /* Build Level 4 */ 163 leal pgtable + 0(%ebx), %edi 164 leal 0x1007 (%edi), %eax 165 movl %eax, 0(%edi) 166 addl %edx, 4(%edi) 167 168 /* Build Level 3 */ 169 leal pgtable + 0x1000(%ebx), %edi 170 leal 0x1007(%edi), %eax 171 movl $4, %ecx 1721: movl %eax, 0x00(%edi) 173 addl %edx, 0x04(%edi) 174 addl $0x00001000, %eax 175 addl $8, %edi 176 decl %ecx 177 jnz 1b 178 179 /* Build Level 2 */ 180 leal pgtable + 0x2000(%ebx), %edi 181 movl $0x00000183, %eax 182 movl $2048, %ecx 1831: movl %eax, 0(%edi) 184 addl %edx, 4(%edi) 185 addl $0x00200000, %eax 186 addl $8, %edi 187 decl %ecx 188 jnz 1b 189 190 /* Enable the boot page tables */ 191 leal pgtable(%ebx), %eax 192 movl %eax, %cr3 193 194 /* Enable Long mode in EFER (Extended Feature Enable Register) */ 195 movl $MSR_EFER, %ecx 196 rdmsr 197 btsl $_EFER_LME, %eax 198 wrmsr 199 200 /* After gdt is loaded */ 201 xorl %eax, %eax 202 lldt %ax 203 movl $__BOOT_TSS, %eax 204 ltr %ax 205 206 /* 207 * Setup for the jump to 64bit mode 208 * 209 * When the jump is performend we will be in long mode but 210 * in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1 211 * (and in turn EFER.LMA = 1). To jump into 64bit mode we use 212 * the new gdt/idt that has __KERNEL_CS with CS.L = 1. 213 * We place all of the values on our mini stack so lret can 214 * used to perform that far jump. 215 */ 216 leal startup_64(%ebp), %eax 217#ifdef CONFIG_EFI_MIXED 218 movl efi32_boot_args(%ebp), %edi 219 cmp $0, %edi 220 jz 1f 221 leal efi64_stub_entry(%ebp), %eax 222 movl efi32_boot_args+4(%ebp), %esi 223 movl efi32_boot_args+8(%ebp), %edx // saved bootparams pointer 224 cmpl $0, %edx 225 jnz 1f 226 /* 227 * efi_pe_entry uses MS calling convention, which requires 32 bytes of 228 * shadow space on the stack even if all arguments are passed in 229 * registers. We also need an additional 8 bytes for the space that 230 * would be occupied by the return address, and this also results in 231 * the correct stack alignment for entry. 232 */ 233 subl $40, %esp 234 leal efi_pe_entry(%ebp), %eax 235 movl %edi, %ecx // MS calling convention 236 movl %esi, %edx 2371: 238#endif 239 pushl $__KERNEL_CS 240 pushl %eax 241 242 /* Enter paged protected Mode, activating Long Mode */ 243 movl $(X86_CR0_PG | X86_CR0_PE), %eax /* Enable Paging and Protected mode */ 244 movl %eax, %cr0 245 246 /* Jump from 32bit compatibility mode into 64bit mode. */ 247 lret 248SYM_FUNC_END(startup_32) 249 250#ifdef CONFIG_EFI_MIXED 251 .org 0x190 252SYM_FUNC_START(efi32_stub_entry) 253 add $0x4, %esp /* Discard return address */ 254 popl %ecx 255 popl %edx 256 popl %esi 257 258 call 1f 2591: pop %ebp 260 subl $1b, %ebp 261 262 movl %esi, efi32_boot_args+8(%ebp) 263SYM_INNER_LABEL(efi32_pe_stub_entry, SYM_L_LOCAL) 264 movl %ecx, efi32_boot_args(%ebp) 265 movl %edx, efi32_boot_args+4(%ebp) 266 movb $0, efi_is64(%ebp) 267 268 /* Save firmware GDTR and code/data selectors */ 269 sgdtl efi32_boot_gdt(%ebp) 270 movw %cs, efi32_boot_cs(%ebp) 271 movw %ds, efi32_boot_ds(%ebp) 272 273 /* Disable paging */ 274 movl %cr0, %eax 275 btrl $X86_CR0_PG_BIT, %eax 276 movl %eax, %cr0 277 278 jmp startup_32 279SYM_FUNC_END(efi32_stub_entry) 280#endif 281 282 .code64 283 .org 0x200 284SYM_CODE_START(startup_64) 285 /* 286 * 64bit entry is 0x200 and it is ABI so immutable! 287 * We come here either from startup_32 or directly from a 288 * 64bit bootloader. 289 * If we come here from a bootloader, kernel(text+data+bss+brk), 290 * ramdisk, zero_page, command line could be above 4G. 291 * We depend on an identity mapped page table being provided 292 * that maps our entire kernel(text+data+bss+brk), zero page 293 * and command line. 294 */ 295 296 cld 297 cli 298 299 /* Setup data segments. */ 300 xorl %eax, %eax 301 movl %eax, %ds 302 movl %eax, %es 303 movl %eax, %ss 304 movl %eax, %fs 305 movl %eax, %gs 306 307 /* 308 * Compute the decompressed kernel start address. It is where 309 * we were loaded at aligned to a 2M boundary. %rbp contains the 310 * decompressed kernel start address. 311 * 312 * If it is a relocatable kernel then decompress and run the kernel 313 * from load address aligned to 2MB addr, otherwise decompress and 314 * run the kernel from LOAD_PHYSICAL_ADDR 315 * 316 * We cannot rely on the calculation done in 32-bit mode, since we 317 * may have been invoked via the 64-bit entry point. 318 */ 319 320 /* Start with the delta to where the kernel will run at. */ 321#ifdef CONFIG_RELOCATABLE 322 leaq startup_32(%rip) /* - $startup_32 */, %rbp 323 324#ifdef CONFIG_EFI_STUB 325/* 326 * If we were loaded via the EFI LoadImage service, startup_32 will be at an 327 * offset to the start of the space allocated for the image. efi_pe_entry will 328 * set up image_offset to tell us where the image actually starts, so that we 329 * can use the full available buffer. 330 * image_offset = startup_32 - image_base 331 * Otherwise image_offset will be zero and has no effect on the calculations. 332 */ 333 movl image_offset(%rip), %eax 334 subq %rax, %rbp 335#endif 336 337 movl BP_kernel_alignment(%rsi), %eax 338 decl %eax 339 addq %rax, %rbp 340 notq %rax 341 andq %rax, %rbp 342 cmpq $LOAD_PHYSICAL_ADDR, %rbp 343 jae 1f 344#endif 345 movq $LOAD_PHYSICAL_ADDR, %rbp 3461: 347 348 /* Target address to relocate to for decompression */ 349 movl BP_init_size(%rsi), %ebx 350 subl $_end, %ebx 351 addq %rbp, %rbx 352 353 /* Set up the stack */ 354 leaq boot_stack_end(%rbx), %rsp 355 356 /* 357 * paging_prepare() and cleanup_trampoline() below can have GOT 358 * references. Adjust the table with address we are running at. 359 * 360 * Zero RAX for adjust_got: the GOT was not adjusted before; 361 * there's no adjustment to undo. 362 */ 363 xorq %rax, %rax 364 365 /* 366 * Calculate the address the binary is loaded at and use it as 367 * a GOT adjustment. 368 */ 369 call 1f 3701: popq %rdi 371 subq $1b, %rdi 372 373 call .Ladjust_got 374 375 /* 376 * At this point we are in long mode with 4-level paging enabled, 377 * but we might want to enable 5-level paging or vice versa. 378 * 379 * The problem is that we cannot do it directly. Setting or clearing 380 * CR4.LA57 in long mode would trigger #GP. So we need to switch off 381 * long mode and paging first. 382 * 383 * We also need a trampoline in lower memory to switch over from 384 * 4- to 5-level paging for cases when the bootloader puts the kernel 385 * above 4G, but didn't enable 5-level paging for us. 386 * 387 * The same trampoline can be used to switch from 5- to 4-level paging 388 * mode, like when starting 4-level paging kernel via kexec() when 389 * original kernel worked in 5-level paging mode. 390 * 391 * For the trampoline, we need the top page table to reside in lower 392 * memory as we don't have a way to load 64-bit values into CR3 in 393 * 32-bit mode. 394 * 395 * We go though the trampoline even if we don't have to: if we're 396 * already in a desired paging mode. This way the trampoline code gets 397 * tested on every boot. 398 */ 399 400 /* Make sure we have GDT with 32-bit code segment */ 401 leaq gdt64(%rip), %rax 402 addq %rax, 2(%rax) 403 lgdt (%rax) 404 405 /* Reload CS so IRET returns to a CS actually in the GDT */ 406 pushq $__KERNEL_CS 407 leaq .Lon_kernel_cs(%rip), %rax 408 pushq %rax 409 lretq 410 411.Lon_kernel_cs: 412 413 /* 414 * paging_prepare() sets up the trampoline and checks if we need to 415 * enable 5-level paging. 416 * 417 * paging_prepare() returns a two-quadword structure which lands 418 * into RDX:RAX: 419 * - Address of the trampoline is returned in RAX. 420 * - Non zero RDX means trampoline needs to enable 5-level 421 * paging. 422 * 423 * RSI holds real mode data and needs to be preserved across 424 * this function call. 425 */ 426 pushq %rsi 427 movq %rsi, %rdi /* real mode address */ 428 call paging_prepare 429 popq %rsi 430 431 /* Save the trampoline address in RCX */ 432 movq %rax, %rcx 433 434 /* 435 * Load the address of trampoline_return() into RDI. 436 * It will be used by the trampoline to return to the main code. 437 */ 438 leaq trampoline_return(%rip), %rdi 439 440 /* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */ 441 pushq $__KERNEL32_CS 442 leaq TRAMPOLINE_32BIT_CODE_OFFSET(%rax), %rax 443 pushq %rax 444 lretq 445trampoline_return: 446 /* Restore the stack, the 32-bit trampoline uses its own stack */ 447 leaq boot_stack_end(%rbx), %rsp 448 449 /* 450 * cleanup_trampoline() would restore trampoline memory. 451 * 452 * RDI is address of the page table to use instead of page table 453 * in trampoline memory (if required). 454 * 455 * RSI holds real mode data and needs to be preserved across 456 * this function call. 457 */ 458 pushq %rsi 459 leaq top_pgtable(%rbx), %rdi 460 call cleanup_trampoline 461 popq %rsi 462 463 /* Zero EFLAGS */ 464 pushq $0 465 popfq 466 467 /* 468 * Previously we've adjusted the GOT with address the binary was 469 * loaded at. Now we need to re-adjust for relocation address. 470 * 471 * Calculate the address the binary is loaded at, so that we can 472 * undo the previous GOT adjustment. 473 */ 474 call 1f 4751: popq %rax 476 subq $1b, %rax 477 478 /* The new adjustment is the relocation address */ 479 movq %rbx, %rdi 480 call .Ladjust_got 481 482/* 483 * Copy the compressed kernel to the end of our buffer 484 * where decompression in place becomes safe. 485 */ 486 pushq %rsi 487 leaq (_bss-8)(%rip), %rsi 488 leaq (_bss-8)(%rbx), %rdi 489 movq $_bss /* - $startup_32 */, %rcx 490 shrq $3, %rcx 491 std 492 rep movsq 493 cld 494 popq %rsi 495 496 /* 497 * The GDT may get overwritten either during the copy we just did or 498 * during extract_kernel below. To avoid any issues, repoint the GDTR 499 * to the new copy of the GDT. 500 */ 501 leaq gdt64(%rbx), %rax 502 leaq gdt(%rbx), %rdx 503 movq %rdx, 2(%rax) 504 lgdt (%rax) 505 506/* 507 * Jump to the relocated address. 508 */ 509 leaq .Lrelocated(%rbx), %rax 510 jmp *%rax 511SYM_CODE_END(startup_64) 512 513#ifdef CONFIG_EFI_STUB 514 .org 0x390 515SYM_FUNC_START(efi64_stub_entry) 516SYM_FUNC_START_ALIAS(efi_stub_entry) 517 and $~0xf, %rsp /* realign the stack */ 518 movq %rdx, %rbx /* save boot_params pointer */ 519 call efi_main 520 movq %rbx,%rsi 521 leaq startup_64(%rax), %rax 522 jmp *%rax 523SYM_FUNC_END(efi64_stub_entry) 524SYM_FUNC_END_ALIAS(efi_stub_entry) 525#endif 526 527 .text 528SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) 529 530/* 531 * Clear BSS (stack is currently empty) 532 */ 533 xorl %eax, %eax 534 leaq _bss(%rip), %rdi 535 leaq _ebss(%rip), %rcx 536 subq %rdi, %rcx 537 shrq $3, %rcx 538 rep stosq 539 540/* 541 * Do the extraction, and jump to the new kernel.. 542 */ 543 pushq %rsi /* Save the real mode argument */ 544 movq %rsi, %rdi /* real mode address */ 545 leaq boot_heap(%rip), %rsi /* malloc area for uncompression */ 546 leaq input_data(%rip), %rdx /* input_data */ 547 movl $z_input_len, %ecx /* input_len */ 548 movq %rbp, %r8 /* output target address */ 549 movl $z_output_len, %r9d /* decompressed length, end of relocs */ 550 call extract_kernel /* returns kernel location in %rax */ 551 popq %rsi 552 553/* 554 * Jump to the decompressed kernel. 555 */ 556 jmp *%rax 557SYM_FUNC_END(.Lrelocated) 558 559/* 560 * Adjust the global offset table 561 * 562 * RAX is the previous adjustment of the table to undo (use 0 if it's the 563 * first time we touch GOT). 564 * RDI is the new adjustment to apply. 565 */ 566.Ladjust_got: 567 /* Walk through the GOT adding the address to the entries */ 568 leaq _got(%rip), %rdx 569 leaq _egot(%rip), %rcx 5701: 571 cmpq %rcx, %rdx 572 jae 2f 573 subq %rax, (%rdx) /* Undo previous adjustment */ 574 addq %rdi, (%rdx) /* Apply the new adjustment */ 575 addq $8, %rdx 576 jmp 1b 5772: 578 ret 579 580 .code32 581/* 582 * This is the 32-bit trampoline that will be copied over to low memory. 583 * 584 * RDI contains the return address (might be above 4G). 585 * ECX contains the base address of the trampoline memory. 586 * Non zero RDX means trampoline needs to enable 5-level paging. 587 */ 588SYM_CODE_START(trampoline_32bit_src) 589 /* Set up data and stack segments */ 590 movl $__KERNEL_DS, %eax 591 movl %eax, %ds 592 movl %eax, %ss 593 594 /* Set up new stack */ 595 leal TRAMPOLINE_32BIT_STACK_END(%ecx), %esp 596 597 /* Disable paging */ 598 movl %cr0, %eax 599 btrl $X86_CR0_PG_BIT, %eax 600 movl %eax, %cr0 601 602 /* Check what paging mode we want to be in after the trampoline */ 603 cmpl $0, %edx 604 jz 1f 605 606 /* We want 5-level paging: don't touch CR3 if it already points to 5-level page tables */ 607 movl %cr4, %eax 608 testl $X86_CR4_LA57, %eax 609 jnz 3f 610 jmp 2f 6111: 612 /* We want 4-level paging: don't touch CR3 if it already points to 4-level page tables */ 613 movl %cr4, %eax 614 testl $X86_CR4_LA57, %eax 615 jz 3f 6162: 617 /* Point CR3 to the trampoline's new top level page table */ 618 leal TRAMPOLINE_32BIT_PGTABLE_OFFSET(%ecx), %eax 619 movl %eax, %cr3 6203: 621 /* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */ 622 pushl %ecx 623 pushl %edx 624 movl $MSR_EFER, %ecx 625 rdmsr 626 btsl $_EFER_LME, %eax 627 wrmsr 628 popl %edx 629 popl %ecx 630 631 /* Enable PAE and LA57 (if required) paging modes */ 632 movl $X86_CR4_PAE, %eax 633 cmpl $0, %edx 634 jz 1f 635 orl $X86_CR4_LA57, %eax 6361: 637 movl %eax, %cr4 638 639 /* Calculate address of paging_enabled() once we are executing in the trampoline */ 640 leal .Lpaging_enabled - trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_OFFSET(%ecx), %eax 641 642 /* Prepare the stack for far return to Long Mode */ 643 pushl $__KERNEL_CS 644 pushl %eax 645 646 /* Enable paging again */ 647 movl $(X86_CR0_PG | X86_CR0_PE), %eax 648 movl %eax, %cr0 649 650 lret 651SYM_CODE_END(trampoline_32bit_src) 652 653 .code64 654SYM_FUNC_START_LOCAL_NOALIGN(.Lpaging_enabled) 655 /* Return from the trampoline */ 656 jmp *%rdi 657SYM_FUNC_END(.Lpaging_enabled) 658 659 /* 660 * The trampoline code has a size limit. 661 * Make sure we fail to compile if the trampoline code grows 662 * beyond TRAMPOLINE_32BIT_CODE_SIZE bytes. 663 */ 664 .org trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_SIZE 665 666 .code32 667SYM_FUNC_START_LOCAL_NOALIGN(.Lno_longmode) 668 /* This isn't an x86-64 CPU, so hang intentionally, we cannot continue */ 6691: 670 hlt 671 jmp 1b 672SYM_FUNC_END(.Lno_longmode) 673 674#include "../../kernel/verify_cpu.S" 675 676 .data 677SYM_DATA_START_LOCAL(gdt64) 678 .word gdt_end - gdt - 1 679 .quad gdt - gdt64 680SYM_DATA_END(gdt64) 681 .balign 8 682SYM_DATA_START_LOCAL(gdt) 683 .word gdt_end - gdt - 1 684 .long 0 685 .word 0 686 .quad 0x00cf9a000000ffff /* __KERNEL32_CS */ 687 .quad 0x00af9a000000ffff /* __KERNEL_CS */ 688 .quad 0x00cf92000000ffff /* __KERNEL_DS */ 689 .quad 0x0080890000000000 /* TS descriptor */ 690 .quad 0x0000000000000000 /* TS continued */ 691SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) 692 693#ifdef CONFIG_EFI_STUB 694SYM_DATA(image_offset, .long 0) 695#endif 696 697#ifdef CONFIG_EFI_MIXED 698SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0) 699SYM_DATA(efi_is64, .byte 1) 700 701#define ST32_boottime 60 // offsetof(efi_system_table_32_t, boottime) 702#define BS32_handle_protocol 88 // offsetof(efi_boot_services_32_t, handle_protocol) 703#define LI32_image_base 32 // offsetof(efi_loaded_image_32_t, image_base) 704 705 .text 706 .code32 707SYM_FUNC_START(efi32_pe_entry) 708/* 709 * efi_status_t efi32_pe_entry(efi_handle_t image_handle, 710 * efi_system_table_32_t *sys_table) 711 */ 712 713 pushl %ebp 714 movl %esp, %ebp 715 pushl %eax // dummy push to allocate loaded_image 716 717 pushl %ebx // save callee-save registers 718 pushl %edi 719 720 call verify_cpu // check for long mode support 721 testl %eax, %eax 722 movl $0x80000003, %eax // EFI_UNSUPPORTED 723 jnz 2f 724 725 call 1f 7261: pop %ebx 727 subl $1b, %ebx 728 729 /* Get the loaded image protocol pointer from the image handle */ 730 leal -4(%ebp), %eax 731 pushl %eax // &loaded_image 732 leal loaded_image_proto(%ebx), %eax 733 pushl %eax // pass the GUID address 734 pushl 8(%ebp) // pass the image handle 735 736 /* 737 * Note the alignment of the stack frame. 738 * sys_table 739 * handle <-- 16-byte aligned on entry by ABI 740 * return address 741 * frame pointer 742 * loaded_image <-- local variable 743 * saved %ebx <-- 16-byte aligned here 744 * saved %edi 745 * &loaded_image 746 * &loaded_image_proto 747 * handle <-- 16-byte aligned for call to handle_protocol 748 */ 749 750 movl 12(%ebp), %eax // sys_table 751 movl ST32_boottime(%eax), %eax // sys_table->boottime 752 call *BS32_handle_protocol(%eax) // sys_table->boottime->handle_protocol 753 addl $12, %esp // restore argument space 754 testl %eax, %eax 755 jnz 2f 756 757 movl 8(%ebp), %ecx // image_handle 758 movl 12(%ebp), %edx // sys_table 759 movl -4(%ebp), %esi // loaded_image 760 movl LI32_image_base(%esi), %esi // loaded_image->image_base 761 movl %ebx, %ebp // startup_32 for efi32_pe_stub_entry 762 /* 763 * We need to set the image_offset variable here since startup_32() will 764 * use it before we get to the 64-bit efi_pe_entry() in C code. 765 */ 766 subl %esi, %ebx 767 movl %ebx, image_offset(%ebp) // save image_offset 768 jmp efi32_pe_stub_entry 769 7702: popl %edi // restore callee-save registers 771 popl %ebx 772 leave 773 ret 774SYM_FUNC_END(efi32_pe_entry) 775 776 .section ".rodata" 777 /* EFI loaded image protocol GUID */ 778 .balign 4 779SYM_DATA_START_LOCAL(loaded_image_proto) 780 .long 0x5b1b31a1 781 .word 0x9562, 0x11d2 782 .byte 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b 783SYM_DATA_END(loaded_image_proto) 784#endif 785 786/* 787 * Stack and heap for uncompression 788 */ 789 .bss 790 .balign 4 791SYM_DATA_LOCAL(boot_heap, .fill BOOT_HEAP_SIZE, 1, 0) 792 793SYM_DATA_START_LOCAL(boot_stack) 794 .fill BOOT_STACK_SIZE, 1, 0 795 .balign 16 796SYM_DATA_END_LABEL(boot_stack, SYM_L_LOCAL, boot_stack_end) 797 798/* 799 * Space for page tables (not in .bss so not zeroed) 800 */ 801 .section ".pgtable","aw",@nobits 802 .balign 4096 803SYM_DATA_LOCAL(pgtable, .fill BOOT_PGT_SIZE, 1, 0) 804 805/* 806 * The page table is going to be used instead of page table in the trampoline 807 * memory. 808 */ 809SYM_DATA_LOCAL(top_pgtable, .fill PAGE_SIZE, 1, 0) 810