cbtable.c - flashprog - Gitiles

 /*
  * 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, 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 int count_lb_records(struct lb_header *head)
 {
 	struct lb_record *rec;
 	int count;

 	count = 0;
 	for_each_lbrec(head, rec) {
 		count++;
 	}

 	return count;
 }

 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 (memcmp(head->signature, "LBIO", 4) != 0)
 			continue;
 		msg_pdbg("Found candidate at: %08lx-%08lx\n",
 			     addr, addr + head->table_bytes);
 		if (head->header_bytes != sizeof(*head)) {
 			msg_perr("Header bytes of %d are incorrect.\n",
 				head->header_bytes);
 			continue;
 		}
 		if (count_lb_records(head) != head->table_entries) {
 			msg_perr("Bad record count: %d.\n",
 				head->table_entries);
 			continue;
 		}
 		if (compute_checksum((uint8_t *) head, sizeof(*head)) != 0) {
 			msg_perr("Bad header checksum.\n");
 			continue;
 		}
 		if (compute_checksum(recs, head->table_bytes)
 		    != head->table_checksum) {
 			msg_perr("Bad table checksum: %04x.\n",
 				head->table_checksum);
 			continue;
 		}
 		msg_pdbg("Found coreboot table at 0x%08lx.\n", addr);
 		return head;

 	};

 	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;
 			start &= ~(getpagesize() - 1);
 			physunmap_unaligned(table_area, BYTES_TO_MAP);
 			// FIXME: table_area is never unmapped below, nor is it unmapped above in the no-forward case
 			table_area = physmap_ro_unaligned("high tables", start, BYTES_TO_MAP);
 			if (ERROR_PTR == table_area) {
 				msg_perr("Failed getting access to coreboot high tables.\n");
 				return -1;
 			}
 			lb_table = find_lb_table(table_area, 0x00000, 0x1000);
 		}
 	}

 	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;
 }
	/*
	* 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, 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 int count_lb_records(struct lb_header *head)
	{
	struct lb_record *rec;
	int count;

	count = 0;
	for_each_lbrec(head, rec) {
	count++;
	}

	return count;
	}

	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 (memcmp(head->signature, "LBIO", 4) != 0)
	continue;
	msg_pdbg("Found candidate at: %08lx-%08lx\n",
	addr, addr + head->table_bytes);
	if (head->header_bytes != sizeof(*head)) {
	msg_perr("Header bytes of %d are incorrect.\n",
	head->header_bytes);
	continue;
	}
	if (count_lb_records(head) != head->table_entries) {
	msg_perr("Bad record count: %d.\n",
	head->table_entries);
	continue;
	}
	if (compute_checksum((uint8_t ) head, sizeof(head)) != 0) {
	msg_perr("Bad header checksum.\n");
	continue;
	}
	if (compute_checksum(recs, head->table_bytes)
	!= head->table_checksum) {
	msg_perr("Bad table checksum: %04x.\n",
	head->table_checksum);
	continue;
	}
	msg_pdbg("Found coreboot table at 0x%08lx.\n", addr);
	return head;

	};

	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;
	start &= ~(getpagesize() - 1);
	physunmap_unaligned(table_area, BYTES_TO_MAP);
	// FIXME: table_area is never unmapped below, nor is it unmapped above in the no-forward case
	table_area = physmap_ro_unaligned("high tables", start, BYTES_TO_MAP);
	if (ERROR_PTR == table_area) {
	msg_perr("Failed getting access to coreboot high tables.\n");
	return -1;
	}
	lb_table = find_lb_table(table_area, 0x00000, 0x1000);
	}
	}

	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;
	}