diff options
Diffstat (limited to 'arch/x86_64/kernel/trampoline.S')
| -rw-r--r-- | arch/x86_64/kernel/trampoline.S | 166 |
1 files changed, 0 insertions, 166 deletions
diff --git a/arch/x86_64/kernel/trampoline.S b/arch/x86_64/kernel/trampoline.S deleted file mode 100644 index e7e2764c461..00000000000 --- a/arch/x86_64/kernel/trampoline.S +++ /dev/null @@ -1,166 +0,0 @@ -/* - * - * Trampoline.S Derived from Setup.S by Linus Torvalds - * - * 4 Jan 1997 Michael Chastain: changed to gnu as. - * 15 Sept 2005 Eric Biederman: 64bit PIC support - * - * Entry: CS:IP point to the start of our code, we are - * in real mode with no stack, but the rest of the - * trampoline page to make our stack and everything else - * is a mystery. - * - * In fact we don't actually need a stack so we don't - * set one up. - * - * On entry to trampoline_data, the processor is in real mode - * with 16-bit addressing and 16-bit data. CS has some value - * and IP is zero. Thus, data addresses need to be absolute - * (no relocation) and are taken with regard to r_base. - * - * With the addition of trampoline_level4_pgt this code can - * now enter a 64bit kernel that lives at arbitrary 64bit - * physical addresses. - * - * If you work on this file, check the object module with objdump - * --full-contents --reloc to make sure there are no relocation - * entries. - */ - -#include <linux/linkage.h> -#include <asm/pgtable.h> -#include <asm/page.h> -#include <asm/msr.h> -#include <asm/segment.h> - -.data - -.code16 - -ENTRY(trampoline_data) -r_base = . - cli # We should be safe anyway - wbinvd - mov %cs, %ax # Code and data in the same place - mov %ax, %ds - mov %ax, %es - mov %ax, %ss - - - movl $0xA5A5A5A5, trampoline_data - r_base - # write marker for master knows we're running - - # Setup stack - movw $(trampoline_stack_end - r_base), %sp - - call verify_cpu # Verify the cpu supports long mode - testl %eax, %eax # Check for return code - jnz no_longmode - - mov %cs, %ax - movzx %ax, %esi # Find the 32bit trampoline location - shll $4, %esi - - # Fixup the vectors - addl %esi, startup_32_vector - r_base - addl %esi, startup_64_vector - r_base - addl %esi, tgdt + 2 - r_base # Fixup the gdt pointer - - /* - * GDT tables in non default location kernel can be beyond 16MB and - * lgdt will not be able to load the address as in real mode default - * operand size is 16bit. Use lgdtl instead to force operand size - * to 32 bit. - */ - - lidtl tidt - r_base # load idt with 0, 0 - lgdtl tgdt - r_base # load gdt with whatever is appropriate - - xor %ax, %ax - inc %ax # protected mode (PE) bit - lmsw %ax # into protected mode - - # flush prefetch and jump to startup_32 - ljmpl *(startup_32_vector - r_base) - - .code32 - .balign 4 -startup_32: - movl $__KERNEL_DS, %eax # Initialize the %ds segment register - movl %eax, %ds - - xorl %eax, %eax - btsl $5, %eax # Enable PAE mode - movl %eax, %cr4 - - # Setup trampoline 4 level pagetables - leal (trampoline_level4_pgt - r_base)(%esi), %eax - movl %eax, %cr3 - - movl $MSR_EFER, %ecx - movl $(1 << _EFER_LME), %eax # Enable Long Mode - xorl %edx, %edx - wrmsr - - xorl %eax, %eax - btsl $31, %eax # Enable paging and in turn activate Long Mode - btsl $0, %eax # Enable protected mode - movl %eax, %cr0 - - /* - * At this point we're in long mode but in 32bit compatibility mode - * with EFER.LME = 1, CS.L = 0, CS.D = 1 (and in turn - * EFER.LMA = 1). Now we want to jump in 64bit mode, to do that we use - * the new gdt/idt that has __KERNEL_CS with CS.L = 1. - */ - ljmp *(startup_64_vector - r_base)(%esi) - - .code64 - .balign 4 -startup_64: - # Now jump into the kernel using virtual addresses - movq $secondary_startup_64, %rax - jmp *%rax - - .code16 -no_longmode: - hlt - jmp no_longmode -#include "verify_cpu.S" - - # Careful these need to be in the same 64K segment as the above; -tidt: - .word 0 # idt limit = 0 - .word 0, 0 # idt base = 0L - - # Duplicate the global descriptor table - # so the kernel can live anywhere - .balign 4 -tgdt: - .short tgdt_end - tgdt # gdt limit - .long tgdt - r_base - .short 0 - .quad 0x00cf9b000000ffff # __KERNEL32_CS - .quad 0x00af9b000000ffff # __KERNEL_CS - .quad 0x00cf93000000ffff # __KERNEL_DS -tgdt_end: - - .balign 4 -startup_32_vector: - .long startup_32 - r_base - .word __KERNEL32_CS, 0 - - .balign 4 -startup_64_vector: - .long startup_64 - r_base - .word __KERNEL_CS, 0 - -trampoline_stack: - .org 0x1000 -trampoline_stack_end: -ENTRY(trampoline_level4_pgt) - .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE - .fill 510,8,0 - .quad level3_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE - -ENTRY(trampoline_end) |