| /* ----------------------------------------------------------------------- * |
| * |
| * Copyright 2013 Intel Corporation; author: Matt Fleming |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, |
| * Boston MA 02110-1301, USA; either version 2 of the License, or |
| * (at your option) any later version; incorporated herein by reference. |
| * |
| * ----------------------------------------------------------------------- */ |
| |
| #define CR0_PG_FLAG 0x80000000 |
| #define MSR_EFER 0xc0000080 |
| |
| .globl kernel_jump |
| .type kernel_jump,@function |
| .code64 |
| kernel_jump: |
| cli |
| |
| /* |
| * Setup our segment selector (0x10) and return address (%rdi) |
| * on the stack in preparation for the far return below. |
| */ |
| mov $0x1000000000, %rcx |
| addq %rcx, %rdi |
| pushq %rdi |
| |
| .code32 |
| pm_code: |
| |
| /* Disable IA-32e mode by clearing IA32_EFER.LME */ |
| xorl %eax, %eax |
| xorl %edx, %edx |
| movl $MSR_EFER, %ecx |
| wrmsr |
| |
| /* Turn off paging to disable long mode */ |
| movl %cr0, %eax |
| andl $~CR0_PG_FLAG, %eax |
| movl %eax, %cr0 |
| |
| /* Far return */ |
| lret |
| |
| .code64 |
| .align 4 |
| .globl efi_handover_32 |
| .type efi_handover_32,@function |
| efi_handover_32: |
| movl $38, errno(%rip) /* ENOSYS */ |
| ret |
| |
| .globl efi_handover_64 |
| .globl efi_handover |
| .type efi_handover_64,@function |
| .type efi_handover,@function |
| efi_handover_64: |
| efi_handover: |
| add $512, %rcx |
| cli |
| jmp *%rcx |
