blob: 5fd1ffe36cba2aa15b08cd13f2946401f89196ee [file] [log] [blame]
/*
* This file is part of the flashrom project.
*
* Copyright (C) 2002 Steven James <pyro@linuxlabs.com>
* Copyright (C) 2002 Linux Networx
* (Written by Eric Biederman <ebiederman@lnxi.com> for Linux Networx)
* Copyright (C) 2006-2009 coresystems GmbH
* (Written by Stefan Reinauer <stepan@coresystems.de> for coresystems GmbH)
* Copyright (C) 2010 Carl-Daniel Hailfinger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <strings.h>
#include <string.h>
#include "flash.h"
#include "programmer.h"
#include "coreboot_tables.h"
static char *cb_vendor = NULL, *cb_model = NULL;
/* Tries to find coreboot IDs in the supplied image and compares them to the current IDs.
* Returns...
* -1 if IDs in the image do not match the IDs embedded in the current firmware,
* 0 if the IDs could not be found in the image or if they match correctly.
*/
int cb_check_image(const uint8_t *image, unsigned int size)
{
const unsigned int *walk;
unsigned int mb_part_offset, mb_vendor_offset;
const char *mb_part, *mb_vendor;
walk = (const unsigned int *)(image + size - 0x10);
walk--;
if ((*walk) == 0 || ((*walk) & 0x3ff) != 0) {
/* Some NVIDIA chipsets store chipset soft straps (IIRC Hypertransport init info etc.) in
* flash at exactly the location where coreboot image size, coreboot vendor name pointer and
* coreboot board name pointer are usually stored. In this case coreboot uses an alternate
* location for the coreboot image data. */
walk = (const unsigned int *)(image + size - 0x80);
walk--;
}
/*
* Check if coreboot last image size is 0 or not a multiple of 1k or
* bigger than the chip or if the pointers to vendor ID or mainboard ID
* are outside the image of if the start of ID strings are nonsensical
* (nonprintable and not \0).
*/
mb_part_offset = *(walk - 1);
mb_vendor_offset = *(walk - 2);
if ((*walk) == 0 || ((*walk) & 0x3ff) != 0 || (*walk) > size ||
mb_part_offset > size || mb_vendor_offset > size) {
msg_pdbg("Flash image seems to be a legacy BIOS. Disabling coreboot-related checks.\n");
return 0;
}
mb_part = (const char *)(image + size - mb_part_offset);
mb_vendor = (const char *)(image + size - mb_vendor_offset);
if (!isprint((unsigned char)*mb_part) ||
!isprint((unsigned char)*mb_vendor)) {
msg_pdbg("Flash image seems to have garbage in the ID location. "
"Disabling coreboot-related checks.\n");
return 0;
}
msg_pdbg("coreboot last image size (not ROM size) is %d bytes.\n", *walk);
msg_pdbg("Manufacturer: %s\n", mb_vendor);
msg_pdbg("Mainboard ID: %s\n", mb_part);
/* If these are not set, the coreboot table was not found. */
if (!cb_vendor || !cb_model)
return 0;
/* These comparisons are case insensitive to make things a little less user^Werror prone. */
if (!strcasecmp(mb_vendor, cb_vendor) && !strcasecmp(mb_part, cb_model)) {
msg_pdbg2("This coreboot image matches this mainboard.\n");
} else {
msg_perr("This coreboot image (%s:%s) does not appear to\n"
"be correct for the detected mainboard (%s:%s).\n",
mb_vendor, mb_part, cb_vendor, cb_model);
return -1;
}
return 0;
}
static unsigned long compute_checksum(void *addr, unsigned long length)
{
uint8_t *ptr;
volatile union {
uint8_t byte[2];
uint16_t word;
} chksum;
unsigned long sum;
unsigned long i;
/* In the most straight forward way possible,
* compute an ip style checksum.
*/
sum = 0;
ptr = addr;
for (i = 0; i < length; i++) {
unsigned long value;
value = ptr[i];
if (i & 1) {
value <<= 8;
}
/* Add the new value */
sum += value;
/* Wrap around the carry */
if (sum > 0xFFFF) {
sum = (sum + (sum >> 16)) & 0xFFFF;
}
}
chksum.byte[0] = sum & 0xff;
chksum.byte[1] = (sum >> 8) & 0xff;
return (~chksum.word) & 0xFFFF;
}
#define for_each_lbrec(head, rec) \
for(rec = (struct lb_record *)(((char *)head) + sizeof(*head)); \
(((char *)rec) < (((char *)head) + sizeof(*head) + head->table_bytes)) && \
(rec->size >= 1) && \
((((char *)rec) + rec->size) <= (((char *)head) + sizeof(*head) + head->table_bytes)); \
rec = (struct lb_record *)(((char *)rec) + rec->size))
static unsigned int count_lb_records(struct lb_header *head)
{
struct lb_record *rec;
unsigned int count;
count = 0;
for_each_lbrec(head, rec) {
count++;
}
return count;
}
static int lb_header_valid(struct lb_header *head, unsigned long addr)
{
if (memcmp(head->signature, "LBIO", 4) != 0)
return 0;
msg_pdbg("Found candidate at: %08lx-%08lx\n",
addr, addr + sizeof(*head) + head->table_bytes);
if (head->header_bytes != sizeof(*head)) {
msg_perr("Header bytes of %d are incorrect.\n",
head->header_bytes);
return 0;
}
if (compute_checksum((uint8_t *) head, sizeof(*head)) != 0) {
msg_perr("Bad header checksum.\n");
return 0;
}
return 1;
}
static int lb_table_valid(struct lb_header *head, struct lb_record *recs)
{
if (compute_checksum(recs, head->table_bytes)
!= head->table_checksum) {
msg_perr("Bad table checksum: %04x.\n",
head->table_checksum);
return 0;
}
if (count_lb_records(head) != head->table_entries) {
msg_perr("Bad record count: %d.\n",
head->table_entries);
return 0;
}
return 1;
}
static struct lb_header *find_lb_table(void *base, unsigned long start,
unsigned long end)
{
unsigned long addr;
/* For now be stupid.... */
for (addr = start; addr < end; addr += 16) {
struct lb_header *head =
(struct lb_header *)(((char *)base) + addr);
struct lb_record *recs =
(struct lb_record *)(((char *)base) + addr + sizeof(*head));
if (!lb_header_valid(head, addr))
continue;
if (!lb_table_valid(head, recs))
continue;
msg_pdbg("Found coreboot table at 0x%08lx.\n", addr);
return head;
}
return NULL;
}
static struct lb_header *find_lb_table_remap(unsigned long start_addr,
uint8_t **table_area)
{
size_t offset;
unsigned long end;
size_t mapping_size;
void *base;
mapping_size = getpagesize();
offset = start_addr % getpagesize();
start_addr -= offset;
base = physmap_ro("high tables", start_addr, mapping_size);
if (ERROR_PTR == base) {
msg_perr("Failed getting access to coreboot high tables.\n");
return NULL;
}
for (end = getpagesize(); offset < end; offset += 16) {
struct lb_record *recs;
struct lb_header *head;
/* No more headers to check. */
if (end - offset < sizeof(*head))
return NULL;
head = (struct lb_header *)(((char *)base) + offset);
if (!lb_header_valid(head, offset))
continue;
if (mapping_size - offset < head->table_bytes + sizeof(*head)) {
size_t prev_mapping_size = mapping_size;
mapping_size = head->table_bytes + sizeof(*head);
mapping_size += offset;
mapping_size += getpagesize() - (mapping_size % getpagesize());
physunmap(base, prev_mapping_size);
base = physmap_ro("high tables", start_addr, mapping_size);
if (ERROR_PTR == base) {
msg_perr("Failed getting access to coreboot high tables.\n");
return NULL;
}
head = (struct lb_header *)(((char *)base) + offset);
}
recs = (struct lb_record *)(((char *)base) + offset + sizeof(*head));
if (!lb_table_valid(head, recs))
continue;
msg_pdbg("Found coreboot table at 0x%08zx.\n", offset);
*table_area = base;
return head;
}
physunmap(base, mapping_size);
return NULL;
}
static void find_mainboard(struct lb_record *ptr, unsigned long addr)
{
struct lb_mainboard *rec;
int max_size;
char vendor[256], part[256];
rec = (struct lb_mainboard *)ptr;
max_size = rec->size - sizeof(*rec);
msg_pdbg("Vendor ID: %.*s, part ID: %.*s\n",
max_size - rec->vendor_idx,
rec->strings + rec->vendor_idx,
max_size - rec->part_number_idx,
rec->strings + rec->part_number_idx);
snprintf(vendor, 255, "%.*s", max_size - rec->vendor_idx, rec->strings + rec->vendor_idx);
snprintf(part, 255, "%.*s", max_size - rec->part_number_idx, rec->strings + rec->part_number_idx);
cb_vendor = strdup(vendor);
cb_model = strdup(part);
}
static struct lb_record *next_record(struct lb_record *rec)
{
return (struct lb_record *)(((char *)rec) + rec->size);
}
static void search_lb_records(struct lb_record *rec, struct lb_record *last, unsigned long addr)
{
struct lb_record *next;
int count;
count = 0;
for (next = next_record(rec); (rec < last) && (next <= last);
rec = next, addr += rec->size) {
next = next_record(rec);
count++;
if (rec->tag == LB_TAG_MAINBOARD) {
find_mainboard(rec, addr);
break;
}
}
}
#define BYTES_TO_MAP (1024*1024)
/* returns 0 if the table was parsed successfully and cb_vendor/cb_model have been set. */
int cb_parse_table(const char **vendor, const char **model)
{
uint8_t *table_area;
unsigned long addr, start;
struct lb_header *lb_table;
struct lb_record *rec, *last;
#if defined(__MACH__) && defined(__APPLE__)
/* This is a hack. DirectHW fails to map physical address 0x00000000.
* Why?
*/
start = 0x400;
#else
start = 0x0;
#endif
table_area = physmap_ro_unaligned("low megabyte", start, BYTES_TO_MAP - start);
if (ERROR_PTR == table_area) {
msg_perr("Failed getting access to coreboot low tables.\n");
return -1;
}
lb_table = find_lb_table(table_area, 0x00000, 0x1000);
if (!lb_table)
lb_table = find_lb_table(table_area, 0xf0000 - start, BYTES_TO_MAP - start);
if (lb_table) {
struct lb_forward *forward = (struct lb_forward *)
(((char *)lb_table) + lb_table->header_bytes);
if (forward->tag == LB_TAG_FORWARD) {
start = forward->forward;
physunmap_unaligned(table_area, BYTES_TO_MAP);
// FIXME: table_area is never unmapped below, nor is it unmapped above in the no-forward case
lb_table = find_lb_table_remap(start, &table_area);
}
}
if (!lb_table) {
msg_pdbg("No coreboot table found.\n");
return -1;
}
addr = ((char *)lb_table) - ((char *)table_area) + start;
msg_pinfo("coreboot table found at 0x%lx.\n",
(unsigned long)lb_table - (unsigned long)table_area + start);
rec = (struct lb_record *)(((char *)lb_table) + lb_table->header_bytes);
last = (struct lb_record *)(((char *)rec) + lb_table->table_bytes);
msg_pdbg("coreboot header(%d) checksum: %04x table(%d) checksum: %04x entries: %d\n",
lb_table->header_bytes, lb_table->header_checksum,
lb_table->table_bytes, lb_table->table_checksum,
lb_table->table_entries);
search_lb_records(rec, last, addr + lb_table->header_bytes);
*vendor = cb_vendor;
*model = cb_model;
return 0;
}