diff options
Diffstat (limited to 'arch/x86_64/boot/compressed/head_64.S')
| -rw-r--r-- | arch/x86_64/boot/compressed/head_64.S | 311 |
1 files changed, 0 insertions, 311 deletions
diff --git a/arch/x86_64/boot/compressed/head_64.S b/arch/x86_64/boot/compressed/head_64.S deleted file mode 100644 index 4946764..0000000 --- a/arch/x86_64/boot/compressed/head_64.S +++ /dev/null @@ -1,311 +0,0 @@ -/* - * linux/boot/head.S - * - * Copyright (C) 1991, 1992, 1993 Linus Torvalds - */ - -/* - * head.S contains the 32-bit startup code. - * - * NOTE!!! Startup happens at absolute address 0x00001000, which is also where - * the page directory will exist. The startup code will be overwritten by - * the page directory. [According to comments etc elsewhere on a compressed - * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] - * - * Page 0 is deliberately kept safe, since System Management Mode code in - * laptops may need to access the BIOS data stored there. This is also - * useful for future device drivers that either access the BIOS via VM86 - * mode. - */ - -/* - * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 - */ -.code32 -.text - -#include <linux/linkage.h> -#include <asm/segment.h> -#include <asm/pgtable.h> -#include <asm/page.h> -#include <asm/msr.h> - -.section ".text.head" - .code32 - .globl startup_32 - -startup_32: - cld - cli - movl $(__KERNEL_DS), %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %ss - -/* 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 - call 1f -1: popl %ebp - subl $1b, %ebp - -/* setup a stack and make sure cpu supports long mode. */ - movl $user_stack_end, %eax - addl %ebp, %eax - movl %eax, %esp - - call verify_cpu - testl %eax, %eax - jnz no_longmode - -/* 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 - * contains the address where we should move the kernel image temporarily - * for safe in-place decompression. - */ - -#ifdef CONFIG_RELOCATABLE - movl %ebp, %ebx - addl $(LARGE_PAGE_SIZE -1), %ebx - andl $LARGE_PAGE_MASK, %ebx -#else - movl $CONFIG_PHYSICAL_START, %ebx -#endif - - /* 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 - -/* - * Prepare for entering 64 bit mode - */ - - /* Load new GDT with the 64bit segments using 32bit descriptor */ - leal gdt(%ebp), %eax - movl %eax, gdt+2(%ebp) - lgdt gdt(%ebp) - - /* Enable PAE mode */ - xorl %eax, %eax - orl $(1 << 5), %eax - movl %eax, %cr4 - - /* - * Build early 4G boot pagetable - */ - /* Initialize Page tables to 0*/ - leal pgtable(%ebx), %edi - xorl %eax, %eax - movl $((4096*6)/4), %ecx - rep stosl - - /* Build Level 4 */ - leal pgtable + 0(%ebx), %edi - leal 0x1007 (%edi), %eax - movl %eax, 0(%edi) - - /* Build Level 3 */ - leal pgtable + 0x1000(%ebx), %edi - leal 0x1007(%edi), %eax - movl $4, %ecx -1: movl %eax, 0x00(%edi) - addl $0x00001000, %eax - addl $8, %edi - decl %ecx - jnz 1b - - /* Build Level 2 */ - leal pgtable + 0x2000(%ebx), %edi - movl $0x00000183, %eax - movl $2048, %ecx -1: movl %eax, 0(%edi) - addl $0x00200000, %eax - addl $8, %edi - decl %ecx - jnz 1b - - /* Enable the boot page tables */ - leal pgtable(%ebx), %eax - movl %eax, %cr3 - - /* Enable Long mode in EFER (Extended Feature Enable Register) */ - movl $MSR_EFER, %ecx - rdmsr - btsl $_EFER_LME, %eax - wrmsr - - /* 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 - * (and in turn EFER.LMA = 1). To jump into 64bit mode we use - * the new gdt/idt that has __KERNEL_CS with CS.L = 1. - * We place all of the values on our mini stack so lret can - * used to perform that far jump. - */ - pushl $__KERNEL_CS - leal startup_64(%ebp), %eax - pushl %eax - - /* Enter paged protected Mode, activating Long Mode */ - movl $0x80000001, %eax /* Enable Paging and Protected mode */ - movl %eax, %cr0 - - /* Jump from 32bit compatibility mode into 64bit mode. */ - lret - -no_longmode: - /* This isn't an x86-64 CPU so hang */ -1: - hlt - jmp 1b - -#include "../../kernel/verify_cpu_64.S" - - /* 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. - */ - - /* Setup data segments. */ - xorl %eax, %eax - movl %eax, %ds - movl %eax, %es - 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 - * 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 - */ - - /* Start with the delta to where the kernel will run at. */ -#ifdef CONFIG_RELOCATABLE - leaq startup_32(%rip) /* - $startup_32 */, %rbp - addq $(LARGE_PAGE_SIZE - 1), %rbp - andq $LARGE_PAGE_MASK, %rbp - movq %rbp, %rbx -#else - movq $CONFIG_PHYSICAL_START, %rbp - movq %rbp, %rbx -#endif - - /* 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 - * where decompression in place becomes safe. - */ - leaq _end(%rip), %r8 - leaq _end(%rbx), %r9 - movq $_end /* - $startup_32 */, %rcx -1: subq $8, %r8 - subq $8, %r9 - movq 0(%r8), %rax - movq %rax, 0(%r9) - subq $8, %rcx - jnz 1b - -/* - * Jump to the relocated address. - */ - leaq relocated(%rbx), %rax - jmp *%rax - -.section ".text" -relocated: - -/* - * Clear BSS - */ - xorq %rax, %rax - leaq _edata(%rbx), %rdi - leaq _end(%rbx), %rcx - subq %rdi, %rcx - cld - rep - stosb - - /* Setup the stack */ - leaq user_stack_end(%rip), %rsp - - /* zero EFLAGS after setting rsp */ - pushq $0 - popfq - -/* - * Do the decompression, and jump to the new kernel.. - */ - pushq %rsi # Save the real mode argument - movq %rsi, %rdi # real mode address - leaq _heap(%rip), %rsi # _heap - leaq input_data(%rip), %rdx # input_data - movl input_len(%rip), %eax - movq %rax, %rcx # input_len - movq %rbp, %r8 # output - call decompress_kernel - popq %rsi - - -/* - * Jump to the decompressed kernel. - */ - jmp *%rbp - - .data -gdt: - .word gdt_end - gdt - .long gdt - .word 0 - .quad 0x0000000000000000 /* NULL descriptor */ - .quad 0x00af9a000000ffff /* __KERNEL_CS */ - .quad 0x00cf92000000ffff /* __KERNEL_DS */ - .quad 0x0080890000000000 /* TS descriptor */ - .quad 0x0000000000000000 /* TS continued */ -gdt_end: - .bss -/* Stack for uncompression */ - .balign 4 -user_stack: - .fill 4096,4,0 -user_stack_end: |