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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright 2012 Nexenta Systems, Inc. All rights reserved.
*/
#include <stdio.h>
#include <errno.h>
#include <assert.h>
#include <unistd.h>
#include <libintl.h>
#include <sys/multiboot.h>
#include <sys/sysmacros.h>
#include "bblk_einfo.h"
#include "boot_utils.h"
#include "mboot_extra.h"
/*
* Common functions to deal with the fake-multiboot encapsulation of the
* bootblock and the location of the extra information area.
*/
/* mboot checksum routine. */
uint32_t
compute_checksum(char *data, uint32_t size)
{
uint32_t *ck_ptr;
uint32_t cksum = 0;
int i;
ck_ptr = (uint32_t *)data;
for (i = 0; i < size; i += sizeof (uint32_t))
cksum += *ck_ptr++;
return (-cksum);
}
/* Given a buffer, look for a multiboot header within it. */
int
find_multiboot(char *buffer, uint32_t buf_size, uint32_t *mboot_off)
{
multiboot_header_t *mboot;
uint32_t *iter;
uint32_t cksum;
uint32_t boundary;
int i = 0;
iter = (uint32_t *)buffer;
*mboot_off = 0;
/* multiboot header has to be within the first 32K. */
boundary = MBOOT_SCAN_SIZE;
if (boundary > buf_size)
boundary = buf_size;
boundary = boundary - sizeof (multiboot_header_t);
for (i = 0; i < boundary; i += 4, iter++) {
mboot = (multiboot_header_t *)iter;
if (mboot->magic != MB_HEADER_MAGIC)
continue;
/* Found magic signature -- check checksum. */
cksum = -(mboot->flags + mboot->magic);
if (mboot->checksum != cksum) {
BOOT_DEBUG("multiboot magic found at %p, but checksum "
"mismatches (is %x, should be %x)\n", mboot,
mboot->checksum, cksum);
continue;
} else {
if (!(mboot->flags & BB_MBOOT_AOUT_FLAG)) {
BOOT_DEBUG("multiboot structure found, but no "
"AOUT kludge specified, skipping.\n");
continue;
} else {
/* proper multiboot structure found. */
*mboot_off = i;
return (BC_SUCCESS);
}
}
}
return (BC_ERROR);
}
/*
* Given a pointer to the extra information area (a sequence of bb_header_ext_t
* + payload chunks), find the extended information structure.
*/
bblk_einfo_t *
find_einfo(char *extra, uint32_t size)
{
bb_header_ext_t *ext_header;
bblk_einfo_t *einfo;
uint32_t cksum;
assert(extra != NULL);
ext_header = (bb_header_ext_t *)extra;
if (ext_header->size > size) {
BOOT_DEBUG("Unable to find extended versioning information, "
"data size too big\n");
return (NULL);
}
cksum = compute_checksum(extra + sizeof (bb_header_ext_t),
ext_header->size);
BOOT_DEBUG("Extended information header checksum is %x\n", cksum);
if (cksum != ext_header->checksum) {
BOOT_DEBUG("Unable to find extended versioning information, "
"data looks corrupted\n");
return (NULL);
}
/*
* Currently we only have one extra header so it must be encapsulating
* the extended information structure.
*/
einfo = (bblk_einfo_t *)(extra + sizeof (bb_header_ext_t));
if (memcmp(einfo->magic, EINFO_MAGIC, EINFO_MAGIC_SIZE) != 0) {
BOOT_DEBUG("Unable to read stage2 extended versioning "
"information, wrong magic identifier\n");
BOOT_DEBUG("Found %s, expected %s\n", einfo->magic,
EINFO_MAGIC);
return (NULL);
}
return (einfo);
}
/*
* Given a pointer to the extra area, add the extended information structure
* encapsulated by a bb_header_ext_t structure.
*/
void
add_einfo(char *extra, char *updt_str, bblk_hs_t *hs, uint32_t avail_space)
{
bb_header_ext_t *ext_hdr;
uint32_t used_space;
unsigned char *dest;
int ret;
assert(extra != NULL);
if (updt_str == NULL) {
BOOT_DEBUG("WARNING: no update string passed to "
"add_stage2_einfo()\n");
return;
}
/* Reserve space for the extra header. */
ext_hdr = (bb_header_ext_t *)extra;
dest = (unsigned char *)extra + sizeof (*ext_hdr);
/* Place the extended information structure. */
ret = prepare_and_write_einfo(dest, updt_str, hs, avail_space,
&used_space);
if (ret != 0) {
(void) fprintf(stderr, gettext("Unable to write the extended "
"versioning information\n"));
return;
}
/* Fill the extended information associated header. */
ext_hdr->size = P2ROUNDUP(used_space, 8);
ext_hdr->checksum = compute_checksum((char *)dest, ext_hdr->size);
}
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