diff options
Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 373 |
1 files changed, 263 insertions, 110 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 1d5dff4123e..2884e0c3e8a 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -21,44 +21,50 @@ /* * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 */ -.code32 -.text + .code32 + .text +#include <linux/init.h> #include <linux/linkage.h> #include <asm/segment.h> -#include <asm/pgtable.h> -#include <asm/page.h> #include <asm/boot.h> #include <asm/msr.h> #include <asm/processor-flags.h> #include <asm/asm-offsets.h> -.section ".text.head" + __HEAD .code32 - .globl startup_32 - -startup_32: +ENTRY(startup_32) + /* + * 32bit entry is 0 and it is ABI so immutable! + * If we come here directly from a bootloader, + * kernel(text+data+bss+brk) ramdisk, zero_page, command line + * all need to be under the 4G limit. + */ cld - /* test KEEP_SEGMENTS flag to see if the bootloader is asking - * us to not reload segments */ + /* + * Test KEEP_SEGMENTS flag to see if the bootloader is asking + * us to not reload segments + */ testb $(1<<6), BP_loadflags(%esi) jnz 1f cli - movl $(__KERNEL_DS), %eax + movl $(__BOOT_DS), %eax movl %eax, %ds movl %eax, %es movl %eax, %ss 1: -/* Calculate the delta between where we were compiled to run +/* + * Calculate the delta between where we were compiled to run * at and where we were actually loaded at. This can only be done * with a short local call on x86. Nothing else will tell us what * address we are running at. The reserved chunk of the real-mode * data at 0x1e4 (defined as a scratch field) are used as the stack * for this calculation. Only 4 bytes are needed. */ - leal (0x1e4+4)(%esi), %esp + leal (BP_scratch+4)(%esi), %esp call 1f 1: popl %ebp subl $1b, %ebp @@ -72,32 +78,30 @@ startup_32: testl %eax, %eax jnz no_longmode -/* Compute the delta between where we were compiled to run at +/* + * Compute the delta between where we were compiled to run at * and where the code will actually run at. - */ -/* %ebp contains the address we are loaded at by the boot loader and %ebx + * + * %ebp contains the address we are loaded at by the boot loader and %ebx * contains the address where we should move the kernel image temporarily * for safe in-place decompression. */ #ifdef CONFIG_RELOCATABLE movl %ebp, %ebx - addl $(PMD_PAGE_SIZE -1), %ebx - andl $PMD_PAGE_MASK, %ebx -#else - movl $CONFIG_PHYSICAL_START, %ebx + movl BP_kernel_alignment(%esi), %eax + decl %eax + addl %eax, %ebx + notl %eax + andl %eax, %ebx + cmpl $LOAD_PHYSICAL_ADDR, %ebx + jge 1f #endif + movl $LOAD_PHYSICAL_ADDR, %ebx +1: - /* Replace the compressed data size with the uncompressed size */ - subl input_len(%ebp), %ebx - movl output_len(%ebp), %eax - addl %eax, %ebx - /* Add 8 bytes for every 32K input block */ - shrl $12, %eax - addl %eax, %ebx - /* Add 32K + 18 bytes of extra slack and align on a 4K boundary */ - addl $(32768 + 18 + 4095), %ebx - andl $~4095, %ebx + /* Target address to relocate to for decompression */ + addl $z_extract_offset, %ebx /* * Prepare for entering 64 bit mode @@ -109,14 +113,14 @@ startup_32: lgdt gdt(%ebp) /* Enable PAE mode */ - xorl %eax, %eax - orl $(X86_CR4_PAE), %eax + movl %cr4, %eax + orl $X86_CR4_PAE, %eax movl %eax, %cr4 /* * Build early 4G boot pagetable */ - /* Initialize Page tables to 0*/ + /* Initialize Page tables to 0 */ leal pgtable(%ebx), %edi xorl %eax, %eax movl $((4096*6)/4), %ecx @@ -157,7 +161,14 @@ startup_32: btsl $_EFER_LME, %eax wrmsr - /* Setup for the jump to 64bit mode + /* After gdt is loaded */ + xorl %eax, %eax + lldt %ax + movl $0x20, %eax + ltr %ax + + /* + * Setup for the jump to 64bit mode * * When the jump is performend we will be in long mode but * in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1 @@ -168,6 +179,13 @@ startup_32: */ pushl $__KERNEL_CS leal startup_64(%ebp), %eax +#ifdef CONFIG_EFI_MIXED + movl efi32_config(%ebp), %ebx + cmp $0, %ebx + jz 1f + leal handover_entry(%ebp), %eax +1: +#endif pushl %eax /* Enter paged protected Mode, activating Long Mode */ @@ -176,28 +194,104 @@ startup_32: /* Jump from 32bit compatibility mode into 64bit mode. */ lret +ENDPROC(startup_32) -no_longmode: - /* This isn't an x86-64 CPU so hang */ -1: - hlt - jmp 1b +#ifdef CONFIG_EFI_MIXED + .org 0x190 +ENTRY(efi32_stub_entry) + add $0x4, %esp /* Discard return address */ + popl %ecx + popl %edx + popl %esi + + leal (BP_scratch+4)(%esi), %esp + call 1f +1: pop %ebp + subl $1b, %ebp -#include "../../kernel/verify_cpu_64.S" + movl %ecx, efi32_config(%ebp) + movl %edx, efi32_config+8(%ebp) + sgdtl efi32_boot_gdt(%ebp) + + leal efi32_config(%ebp), %eax + movl %eax, efi_config(%ebp) + + jmp startup_32 +ENDPROC(efi32_stub_entry) +#endif - /* Be careful here startup_64 needs to be at a predictable - * address so I can export it in an ELF header. Bootloaders - * should look at the ELF header to find this address, as - * it may change in the future. - */ .code64 .org 0x200 ENTRY(startup_64) - /* We come here either from startup_32 or directly from a - * 64bit bootloader. If we come here from a bootloader we depend on - * an identity mapped page table being provied that maps our - * entire text+data+bss and hopefully all of memory. + /* + * 64bit entry is 0x200 and it is ABI so immutable! + * We come here either from startup_32 or directly from a + * 64bit bootloader. + * If we come here from a bootloader, kernel(text+data+bss+brk), + * ramdisk, zero_page, command line could be above 4G. + * We depend on an identity mapped page table being provided + * that maps our entire kernel(text+data+bss+brk), zero page + * and command line. */ +#ifdef CONFIG_EFI_STUB + /* + * The entry point for the PE/COFF executable is efi_pe_entry, so + * only legacy boot loaders will execute this jmp. + */ + jmp preferred_addr + +ENTRY(efi_pe_entry) + movq %rcx, efi64_config(%rip) /* Handle */ + movq %rdx, efi64_config+8(%rip) /* EFI System table pointer */ + + leaq efi64_config(%rip), %rax + movq %rax, efi_config(%rip) + + call 1f +1: popq %rbp + subq $1b, %rbp + + /* + * Relocate efi_config->call(). + */ + addq %rbp, efi64_config+88(%rip) + + movq %rax, %rdi + call make_boot_params + cmpq $0,%rax + je fail + mov %rax, %rsi + leaq startup_32(%rip), %rax + movl %eax, BP_code32_start(%rsi) + jmp 2f /* Skip the relocation */ + +handover_entry: + call 1f +1: popq %rbp + subq $1b, %rbp + + /* + * Relocate efi_config->call(). + */ + movq efi_config(%rip), %rax + addq %rbp, 88(%rax) +2: + movq efi_config(%rip), %rdi + call efi_main + movq %rax,%rsi + cmpq $0,%rax + jne 2f +fail: + /* EFI init failed, so hang. */ + hlt + jmp fail +2: + movl BP_code32_start(%esi), %eax + leaq preferred_addr(%rax), %rax + jmp *%rax + +preferred_addr: +#endif /* Setup data segments. */ xorl %eax, %eax @@ -206,54 +300,57 @@ ENTRY(startup_64) movl %eax, %ss movl %eax, %fs movl %eax, %gs - lldt %ax - movl $0x20, %eax - ltr %ax - /* Compute the decompressed kernel start address. It is where + /* + * Compute the decompressed kernel start address. It is where * we were loaded at aligned to a 2M boundary. %rbp contains the * decompressed kernel start address. * * If it is a relocatable kernel then decompress and run the kernel * from load address aligned to 2MB addr, otherwise decompress and - * run the kernel from CONFIG_PHYSICAL_START + * run the kernel from LOAD_PHYSICAL_ADDR + * + * We cannot rely on the calculation done in 32-bit mode, since we + * may have been invoked via the 64-bit entry point. */ /* Start with the delta to where the kernel will run at. */ #ifdef CONFIG_RELOCATABLE leaq startup_32(%rip) /* - $startup_32 */, %rbp - addq $(PMD_PAGE_SIZE - 1), %rbp - andq $PMD_PAGE_MASK, %rbp - movq %rbp, %rbx -#else - movq $CONFIG_PHYSICAL_START, %rbp - movq %rbp, %rbx + movl BP_kernel_alignment(%rsi), %eax + decl %eax + addq %rax, %rbp + notq %rax + andq %rax, %rbp + cmpq $LOAD_PHYSICAL_ADDR, %rbp + jge 1f #endif + movq $LOAD_PHYSICAL_ADDR, %rbp +1: + + /* Target address to relocate to for decompression */ + leaq z_extract_offset(%rbp), %rbx - /* Replace the compressed data size with the uncompressed size */ - movl input_len(%rip), %eax - subq %rax, %rbx - movl output_len(%rip), %eax - addq %rax, %rbx - /* Add 8 bytes for every 32K input block */ - shrq $12, %rax - addq %rax, %rbx - /* Add 32K + 18 bytes of extra slack and align on a 4K boundary */ - addq $(32768 + 18 + 4095), %rbx - andq $~4095, %rbx - -/* Copy the compressed kernel to the end of our buffer + /* Set up the stack */ + leaq boot_stack_end(%rbx), %rsp + + /* Zero EFLAGS */ + pushq $0 + popfq + +/* + * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. */ - leaq _end_before_pgt(%rip), %r8 - leaq _end_before_pgt(%rbx), %r9 - movq $_end_before_pgt /* - $startup_32 */, %rcx -1: subq $8, %r8 - subq $8, %r9 - movq 0(%r8), %rax - movq %rax, 0(%r9) - subq $8, %rcx - jnz 1b + pushq %rsi + leaq (_bss-8)(%rip), %rsi + leaq (_bss-8)(%rbx), %rdi + movq $_bss /* - $startup_32 */, %rcx + shrq $3, %rcx + std + rep movsq + cld + popq %rsi /* * Jump to the relocated address. @@ -261,45 +358,72 @@ ENTRY(startup_64) leaq relocated(%rbx), %rax jmp *%rax -.section ".text" +#ifdef CONFIG_EFI_STUB + .org 0x390 +ENTRY(efi64_stub_entry) + movq %rdi, efi64_config(%rip) /* Handle */ + movq %rsi, efi64_config+8(%rip) /* EFI System table pointer */ + + leaq efi64_config(%rip), %rax + movq %rax, efi_config(%rip) + + movq %rdx, %rsi + jmp handover_entry +ENDPROC(efi64_stub_entry) +#endif + + .text relocated: /* - * Clear BSS + * Clear BSS (stack is currently empty) */ - xorq %rax, %rax - leaq _edata(%rbx), %rdi - leaq _end_before_pgt(%rbx), %rcx + xorl %eax, %eax + leaq _bss(%rip), %rdi + leaq _ebss(%rip), %rcx subq %rdi, %rcx - cld - rep - stosb - - /* Setup the stack */ - leaq boot_stack_end(%rip), %rsp - - /* zero EFLAGS after setting rsp */ - pushq $0 - popfq + shrq $3, %rcx + rep stosq /* + * Adjust our own GOT + */ + leaq _got(%rip), %rdx + leaq _egot(%rip), %rcx +1: + cmpq %rcx, %rdx + jae 2f + addq %rbx, (%rdx) + addq $8, %rdx + jmp 1b +2: + +/* * Do the decompression, and jump to the new kernel.. */ - pushq %rsi # Save the real mode argument - movq %rsi, %rdi # real mode address - leaq boot_heap(%rip), %rsi # malloc area for uncompression - leaq input_data(%rip), %rdx # input_data - movl input_len(%rip), %eax - movq %rax, %rcx # input_len - movq %rbp, %r8 # output - call decompress_kernel + pushq %rsi /* Save the real mode argument */ + movq %rsi, %rdi /* real mode address */ + leaq boot_heap(%rip), %rsi /* malloc area for uncompression */ + leaq input_data(%rip), %rdx /* input_data */ + movl $z_input_len, %ecx /* input_len */ + movq %rbp, %r8 /* output target address */ + movq $z_output_len, %r9 /* decompressed length */ + call decompress_kernel /* returns kernel location in %rax */ popq %rsi - /* * Jump to the decompressed kernel. */ - jmp *%rbp + jmp *%rax + + .code32 +no_longmode: + /* This isn't an x86-64 CPU so hang */ +1: + hlt + jmp 1b + +#include "../../kernel/verify_cpu.S" .data gdt: @@ -313,11 +437,40 @@ gdt: .quad 0x0000000000000000 /* TS continued */ gdt_end: -.bss -/* Stack and heap for uncompression */ -.balign 4 +#ifdef CONFIG_EFI_STUB +efi_config: + .quad 0 + +#ifdef CONFIG_EFI_MIXED + .global efi32_config +efi32_config: + .fill 11,8,0 + .quad efi64_thunk + .byte 0 +#endif + + .global efi64_config +efi64_config: + .fill 11,8,0 + .quad efi_call + .byte 1 +#endif /* CONFIG_EFI_STUB */ + +/* + * Stack and heap for uncompression + */ + .bss + .balign 4 boot_heap: .fill BOOT_HEAP_SIZE, 1, 0 boot_stack: .fill BOOT_STACK_SIZE, 1, 0 boot_stack_end: + +/* + * Space for page tables (not in .bss so not zeroed) + */ + .section ".pgtable","a",@nobits + .balign 4096 +pgtable: + .fill 6*4096, 1, 0 |