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Remove the usage of Multiboot's "a.out kludge" to tell the boot loader to
reserve some more space for the BSS section than the binary says.  This
trick was used to leave room after the kernel's image to copy the symbol
table following the format required by ksyms_init.  (It was also used to
workaround a bug in the physical address fields of the binary, but this has
been long fixed.)  Yes, the MULTIBOOT_SYMTAB_SPACE option goes away; yay!

Instead, copy the required data after the kernel in a way that avoids having
to reserve space and use the new ksyms_init_explicit function to avoid the
need to construct a minimal ELF image.

Fixes ksyms when using an "unpatched" GRUB (one that does not contain the
fix to honour the "a.out kludge" for ELF images, even when present) -- i.e.
ddb and lkms.  As a side effect, the new code is much clearer to read and
digest.

Closes PR port-i386/32865.

/*	$NetBSD: multiboot.h,v 1.4 2006/10/25 13:56:16 jmmv Exp $	*/

/*-
 * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Julio M. Merino Vidal.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#if defined(_KERNEL)

#include "opt_multiboot.h"

#if defined(MULTIBOOT)

/* --------------------------------------------------------------------- */

/*
 * Multiboot header structure.
 */
#define MULTIBOOT_HEADER_MAGIC		0x1BADB002
#define MULTIBOOT_HEADER_MODS_ALIGNED	0x00000001
#define MULTIBOOT_HEADER_WANT_MEMORY	0x00000002
#define MULTIBOOT_HEADER_HAS_VBE	0x00000004
#define MULTIBOOT_HEADER_HAS_ADDR	0x00010000

#if !defined(_LOCORE)
struct multiboot_header {
	uint32_t	mh_magic;
	uint32_t	mh_flags;
	uint32_t	mh_checksum;

	/* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
	paddr_t		mh_header_addr;
	paddr_t		mh_load_addr;
	paddr_t		mh_load_end_addr;
	paddr_t		mh_bss_end_addr;
	paddr_t		mh_entry_addr;

	/* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE. */
	uint32_t	mh_mode_type;
	uint32_t	mh_width;
	uint32_t	mh_height;
	uint32_t	mh_depth;
};
#endif /* !defined(_LOCORE) */

/*
 * Symbols defined in locore.S.
 */
#if !defined(_LOCORE)
extern struct multiboot_header *Multiboot_Header;
#endif /* !defined(_LOCORE) */

/* --------------------------------------------------------------------- */

/*
 * Multiboot information structure.
 */
#define MULTIBOOT_INFO_MAGIC		0x2BADB002
#define MULTIBOOT_INFO_HAS_MEMORY	0x00000001
#define MULTIBOOT_INFO_HAS_BOOT_DEVICE	0x00000002
#define MULTIBOOT_INFO_HAS_CMDLINE	0x00000004
#define MULTIBOOT_INFO_HAS_MODS		0x00000008
#define MULTIBOOT_INFO_HAS_AOUT_SYMS	0x00000010
#define MULTIBOOT_INFO_HAS_ELF_SYMS	0x00000020
#define MULTIBOOT_INFO_HAS_MMAP		0x00000040
#define MULTIBOOT_INFO_HAS_DRIVES	0x00000080
#define MULTIBOOT_INFO_HAS_CONFIG_TABLE	0x00000100
#define MULTIBOOT_INFO_HAS_LOADER_NAME	0x00000200
#define MULTIBOOT_INFO_HAS_APM_TABLE	0x00000400
#define MULTIBOOT_INFO_HAS_VBE		0x00000800

#if !defined(_LOCORE)
struct multiboot_info {
	uint32_t	mi_flags;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_MEMORY. */
	uint32_t	mi_mem_lower;
	uint32_t	mi_mem_upper;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_BOOT_DEVICE. */
	uint8_t		mi_boot_device_part3;
	uint8_t		mi_boot_device_part2;
	uint8_t		mi_boot_device_part1;
	uint8_t		mi_boot_device_drive;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_CMDLINE. */
	char *		mi_cmdline;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_MODS. */
	uint32_t	unused_mi_mods_count;
	vaddr_t		unused_mi_mods_addr;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_{AOUT,ELF}_SYMS. */
	uint32_t	mi_elfshdr_num;
	uint32_t	mi_elfshdr_size;
	vaddr_t		mi_elfshdr_addr;
	uint32_t	mi_elfshdr_shndx;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_MMAP. */
	uint32_t	mi_mmap_length;
	vaddr_t		mi_mmap_addr;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_DRIVES. */
	uint32_t	mi_drives_length;
	vaddr_t		mi_drives_addr;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_CONFIG_TABLE. */
	void *		unused_mi_config_table;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_LOADER_NAME. */
	char *		mi_loader_name;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_APM. */
	void *		unused_mi_apm_table;

	/* Valid if mi_flags sets MULTIBOOT_INFO_HAS_VBE. */
	void *		unused_mi_vbe_control_info;
	void *		unused_mi_vbe_mode_info;
	paddr_t		unused_mi_vbe_interface_seg;
	paddr_t		unused_mi_vbe_interface_off;
	uint32_t	unused_mi_vbe_interface_len;
};

/* --------------------------------------------------------------------- */

/*
 * Drive information.  This describes an entry in the drives table as
 * pointed to by mi_drives_addr.
 */
struct multiboot_drive {
	uint32_t	md_length;
	uint8_t		md_number;
	uint8_t		md_mode;
	uint16_t	md_cylinders;
	uint8_t		md_heads;
	uint8_t		md_sectors;

	/* The variable-sized 'ports' field comes here, so this structure
	 * can be longer. */
};

/* --------------------------------------------------------------------- */

/*
 * Memory mapping.  This describes an entry in the memory mappings table
 * as pointed to by mi_mmap_addr.
 *
 * Be aware that mm_size specifies the size of all other fields *except*
 * for mm_size.  In order to jump between two different entries, you
 * have to count mm_size + 4 bytes.
 */
struct multiboot_mmap {
	uint32_t	mm_size;
	uint64_t	mm_base_addr;
	uint64_t	mm_length;
	uint32_t	mm_type;
};

#endif /* !defined(_LOCORE) */

/* --------------------------------------------------------------------- */

/*
 * Prototypes for public functions defined in multiboot.c.
 */
#if !defined(_LOCORE)
void		multiboot_pre_reloc(struct multiboot_info *);
void		multiboot_post_reloc(void);
void		multiboot_print_info(void);
boolean_t	multiboot_ksyms_init(void);
#endif /* !defined(_LOCORE) */

/* --------------------------------------------------------------------- */

#endif /* defined(MULTIBOOT) */

#endif /* defined(_KERNEL) */