2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #define __ELF_WORD_SIZE 64
31 #include <sys/param.h>
33 #include <sys/linker.h>
35 #include <machine/_inttypes.h>
38 #include <i386/include/bootinfo.h>
39 #include <machine/elf.h>
42 #include "bootstrap.h"
43 #include "libuserboot.h"
45 static int elf64_exec(struct preloaded_file *amp);
46 static int elf64_obj_exec(struct preloaded_file *amp);
48 struct file_format amd64_elf = { elf64_loadfile, elf64_exec };
49 struct file_format amd64_elf_obj = { elf64_obj_loadfile, elf64_obj_exec };
51 #define MSR_EFER 0xc0000080
52 #define EFER_LME 0x00000100
53 #define EFER_LMA 0x00000400 /* Long mode active (R) */
54 #define CR4_PAE 0x00000020
55 #define CR4_VMXE (1UL << 13)
56 #define CR4_PSE 0x00000010
57 #define CR0_PG 0x80000000
58 #define CR0_PE 0x00000001 /* Protected mode Enable */
59 #define CR0_NE 0x00000020 /* Numeric Error enable (EX16 vs IRQ13) */
66 typedef uint64_t p4_entry_t;
67 typedef uint64_t p3_entry_t;
68 typedef uint64_t p2_entry_t;
70 #define GUEST_NULL_SEL 0
71 #define GUEST_CODE_SEL 1
72 #define GUEST_DATA_SEL 2
73 #define GUEST_GDTR_LIMIT (3 * 8 - 1)
76 setup_freebsd_gdt(uint64_t *gdtr)
78 gdtr[GUEST_NULL_SEL] = 0;
79 gdtr[GUEST_CODE_SEL] = 0x0020980000000000;
80 gdtr[GUEST_DATA_SEL] = 0x0000900000000000;
84 * There is an ELF kernel and one or more ELF modules loaded.
85 * We wish to start executing the kernel image, so make such
86 * preparations as are required, and do so.
89 elf64_exec(struct preloaded_file *fp)
91 struct file_metadata *md;
93 vm_offset_t modulep, kernend;
102 if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
104 ehdr = (Elf_Ehdr *)&(md->md_data);
106 err = bi_load64(fp->f_args, &modulep, &kernend);
110 bzero(PT4, PAGE_SIZE);
111 bzero(PT3, PAGE_SIZE);
112 bzero(PT2, PAGE_SIZE);
115 * Build a scratch stack at physical 0x1000, page tables:
123 * This is kinda brutal, but every single 1GB VM memory segment
124 * points to the same first 1GB of physical memory. But it is
125 * more than adequate.
127 for (i = 0; i < 512; i++) {
128 /* Each slot of the level 4 pages points to the same level 3 page */
129 PT4[i] = (p4_entry_t) 0x3000;
130 PT4[i] |= PG_V | PG_RW | PG_U;
132 /* Each slot of the level 3 pages points to the same level 2 page */
133 PT3[i] = (p3_entry_t) 0x4000;
134 PT3[i] |= PG_V | PG_RW | PG_U;
136 /* The level 2 page slots are mapped with 2MB pages for 1GB. */
137 PT2[i] = i * (2 * 1024 * 1024);
138 PT2[i] |= PG_V | PG_RW | PG_PS | PG_U;
142 printf("Start @ %#"PRIx64" ...\n", ehdr->e_entry);
147 stack[0] = 0; /* return address */
150 CALLBACK(copyin, stack, 0x1000, sizeof(stack));
151 CALLBACK(copyin, PT4, 0x2000, sizeof(PT4));
152 CALLBACK(copyin, PT3, 0x3000, sizeof(PT3));
153 CALLBACK(copyin, PT2, 0x4000, sizeof(PT2));
154 CALLBACK(setreg, 4, 0x1000);
156 CALLBACK(setmsr, MSR_EFER, EFER_LMA | EFER_LME);
157 CALLBACK(setcr, 4, CR4_PAE | CR4_VMXE);
158 CALLBACK(setcr, 3, 0x2000);
159 CALLBACK(setcr, 0, CR0_PG | CR0_PE | CR0_NE);
161 setup_freebsd_gdt(gdtr);
162 CALLBACK(copyin, gdtr, 0x5000, sizeof(gdtr));
163 CALLBACK(setgdt, 0x5000, sizeof(gdtr));
165 CALLBACK(exec, ehdr->e_entry);
167 panic("exec returned");
171 elf64_obj_exec(struct preloaded_file *fp)