/*-
 * 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.
 */

#define __ELF_WORD_SIZE 64
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/linker.h>
#include <string.h>
#include <machine/bootinfo.h>
#include <machine/elf.h>
#include <stand.h>

#include "bootstrap.h"
#include "libi386.h"
#include "btxv86.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 PG_V	0x001
#define PG_RW	0x002
#define PG_PS	0x080

typedef uint64_t p4_entry_t;
typedef uint64_t p3_entry_t;
typedef uint64_t p2_entry_t;
extern p4_entry_t PT4[];
extern p3_entry_t PT3[];
extern p2_entry_t PT2[];

uint32_t entry_hi;
uint32_t entry_lo;

extern void amd64_tramp();

/*
 * 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;

    if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
	return(EFTYPE);
    ehdr = (Elf_Ehdr *)&(md->md_data);

    err = bi_load64(fp->f_args, &modulep, &kernend, 1);
    if (err != 0)
	return(err);

    bzero(PT4, PAGE_SIZE);
    bzero(PT3, PAGE_SIZE);
    bzero(PT2, PAGE_SIZE);

    /*
     * 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)VTOP((uintptr_t)&PT3[0]);
	PT4[i] |= PG_V | PG_RW;

	/* Each slot of the level 3 pages points to the same level 2 page */
	PT3[i] = (p3_entry_t)VTOP((uintptr_t)&PT2[0]);
	PT3[i] |= PG_V | PG_RW;

	/* 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;
    }

    entry_lo = ehdr->e_entry & 0xffffffff;
    entry_hi = (ehdr->e_entry >> 32) & 0xffffffff;
#ifdef DEBUG
    printf("Start @ %#llx ...\n", ehdr->e_entry);
#endif

    dev_cleanup();
    __exec((void *)VTOP(amd64_tramp), modulep, kernend);

    panic("exec returned");
}

static int
elf64_obj_exec(struct preloaded_file *fp)
{
	return (EFTYPE);
}
