1/*- 2 * Copyright (c) 2013 The FreeBSD Foundation 3 * Copyright (c) 2023 Ahmad Khalifa <ahmadkhalifa570@gmail.com> 4 * 5 * This software was developed by Benno Rice under sponsorship from 6 * the FreeBSD Foundation. 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <machine/asmacros.h> 30 31 .text 32 .globl amd64_tramp 33 34/* 35 * void amd64_tramp(uint32_t stack, void *copy_finish, uint32_t kernend, 36 * uint32_t modulep, uint32_t pagetable, uint32_t gdtr, uint64_t entry) 37 */ 38amd64_tramp: 39 cli /* Make sure we don't get interrupted. */ 40 41 calll *8(%esp) /* Call copy_finish so we're all ready to go. */ 42 43 movl %cr0, %eax /* Paging may be enabled, disable it. */ 44 andl $0x7FFFFFFF, %eax 45 movl %eax, %cr0 46 47 movl %cr4, %eax /* PAE may be disabled, enable it. */ 48 orl $0x20, %eax 49 movl %eax, %cr4 50 51 movl 20(%esp), %eax /* Swap page tables. */ 52 movl %eax, %cr3 53 54 movl $0xC0000080, %ecx /* Enable long mode. */ 55 rdmsr 56 orl $0x100, %eax 57 wrmsr 58 59 movl 12(%esp), %edi /* Stash the kernel and GDT values for later. */ 60 movl 16(%esp), %esi 61 movl 24(%esp), %ebx 62 movl 28(%esp), %edx 63 movl 32(%esp), %ebp 64 65 movl 4(%esp), %esp /* Switch to our temporary stack. */ 66 67 movl %cr0, %eax /* Enable paging and enter compatibility mode. */ 68 orl $0x80000000, %eax 69 movl %eax, %cr0 70 71 lgdtl (%ebx) /* Load GDT. */ 72 73 pushl %edi /* Push kernend. */ 74 pushl %esi /* Push modulep. */ 75 pushl $0x0 76 pushl %ebp /* Push 64-bit entry address. */ 77 pushl %edx 78 79 calll 0f /* Find the address of ".longmode". */ 800: popl %eax 81 addl $(.longmode-0b), %eax 82 83 pushl $0x8 /* Push CS. */ 84 pushl %eax /* Push the address. */ 85 lretl /* "Return" to 64-bit code. */ 86 87 .code64 88 89.longmode: 90 retq /* "Return" to kernel entry. */ 91 92 .code32 93 94 ALIGN_TEXT 95amd64_tramp_end: 96 97 .data 98 .globl amd64_tramp_size 99amd64_tramp_size: 100 .long amd64_tramp_end-amd64_tramp 101