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/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define __ELF_WORD_SIZE 64
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/linker.h>
#include <string.h>
#include <i386/include/bootinfo.h>
#include <machine/elf.h>
#include <stand.h>
#include "bootstrap.h"
#include "libuserboot.h"
static int elf64_exec(struct preloaded_file *amp);
static int elf64_obj_exec(struct preloaded_file *amp);
struct file_format amd64_elf = { elf64_loadfile, elf64_exec };
struct file_format amd64_elf_obj = { elf64_obj_loadfile, elf64_obj_exec };
#define MSR_EFER 0xc0000080
#define EFER_LME 0x00000100
#define EFER_LMA 0x00000400 /* Long mode active (R) */
#define CR4_PAE 0x00000020
#define CR4_VMXE (1UL << 13)
#define CR4_PSE 0x00000010
#define CR0_PG 0x80000000
#define CR0_PE 0x00000001 /* Protected mode Enable */
#define CR0_NE 0x00000020 /* Numeric Error enable (EX16 vs IRQ13) */
#define PG_V 0x001
#define PG_RW 0x002
#define PG_U 0x004
#define PG_PS 0x080
typedef u_int64_t p4_entry_t;
typedef u_int64_t p3_entry_t;
typedef u_int64_t p2_entry_t;
#define GUEST_NULL_SEL 0
#define GUEST_CODE_SEL 1
#define GUEST_DATA_SEL 2
#define GUEST_GDTR_LIMIT (3 * 8 - 1)
static void
setup_freebsd_gdt(uint64_t *gdtr)
{
gdtr[GUEST_NULL_SEL] = 0;
gdtr[GUEST_CODE_SEL] = 0x0020980000000000;
gdtr[GUEST_DATA_SEL] = 0x0000900000000000;
}
/*
* There is an ELF kernel and one or more ELF modules loaded.
* We wish to start executing the kernel image, so make such
* preparations as are required, and do so.
*/
static int
elf64_exec(struct preloaded_file *fp)
{
struct file_metadata *md;
Elf_Ehdr *ehdr;
vm_offset_t modulep, kernend;
int err;
int i;
uint32_t stack[1024];
p4_entry_t PT4[512];
p3_entry_t PT3[512];
p2_entry_t PT2[512];
uint64_t gdtr[3];
if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
return(EFTYPE);
ehdr = (Elf_Ehdr *)&(md->md_data);
err = bi_load64(fp->f_args, &modulep, &kernend);
if (err != 0)
return(err);
bzero(PT4, PAGE_SIZE);
bzero(PT3, PAGE_SIZE);
bzero(PT2, PAGE_SIZE);
/*
* Build a scratch stack at physical 0x1000, page tables:
* PT4 at 0x2000,
* PT3 at 0x3000,
* PT2 at 0x4000,
* gdtr at 0x5000,
*/
/*
* This is kinda brutal, but every single 1GB VM memory segment
* points to the same first 1GB of physical memory. But it is
* more than adequate.
*/
for (i = 0; i < 512; i++) {
/* Each slot of the level 4 pages points to the same level 3 page */
PT4[i] = (p4_entry_t) 0x3000;
PT4[i] |= PG_V | PG_RW | PG_U;
/* Each slot of the level 3 pages points to the same level 2 page */
PT3[i] = (p3_entry_t) 0x4000;
PT3[i] |= PG_V | PG_RW | PG_U;
/* The level 2 page slots are mapped with 2MB pages for 1GB. */
PT2[i] = i * (2 * 1024 * 1024);
PT2[i] |= PG_V | PG_RW | PG_PS | PG_U;
}
#ifdef DEBUG
printf("Start @ %#llx ...\n", ehdr->e_entry);
#endif
dev_cleanup();
stack[0] = 0; /* return address */;
stack[1] = modulep;
stack[2] = kernend;
CALLBACK(copyin, stack, 0x1000, sizeof(stack));
CALLBACK(copyin, PT4, 0x2000, sizeof(PT4));
CALLBACK(copyin, PT3, 0x3000, sizeof(PT3));
CALLBACK(copyin, PT2, 0x4000, sizeof(PT2));
CALLBACK(setreg, 4, 0x1000);
CALLBACK(setmsr, MSR_EFER, EFER_LMA | EFER_LME);
CALLBACK(setcr, 4, CR4_PAE | CR4_VMXE);
CALLBACK(setcr, 3, 0x2000);
CALLBACK(setcr, 0, CR0_PG | CR0_PE | CR0_NE);
setup_freebsd_gdt(gdtr);
CALLBACK(copyin, gdtr, 0x5000, sizeof(gdtr));
CALLBACK(setgdt, 0x5000, sizeof(gdtr));
CALLBACK(exec, ehdr->e_entry);
panic("exec returned");
}
static int
elf64_obj_exec(struct preloaded_file *fp)
{
return (EFTYPE);
}
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