Flashrom update from Stefan, resolve issue 21

Corresponding to flashrom svn r34 and coreboot v2 svn r2111.
diff --git a/lbtable.c b/lbtable.c
new file mode 100644
index 0000000..f982672
--- /dev/null
+++ b/lbtable.c
@@ -0,0 +1,193 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include "../../src/include/boot/linuxbios_tables.h"
+#include "debug.h"
+
+char *lb_part=NULL, *lb_vendor=NULL;
+
+static unsigned long compute_checksum(void *addr, unsigned long length)
+{
+	uint8_t *ptr;
+	volatile union {
+		uint8_t  byte[2];
+		uint16_t word;
+	} value;
+	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;
+		}
+	}
+	value.byte[0] = sum & 0xff;
+	value.byte[1] = (sum >> 8) & 0xff;
+	return (~value.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;
+		printf_debug( "Found canidate at: %08lx-%08lx\n", 
+			addr, addr + head->table_bytes);
+		if (head->header_bytes != sizeof(*head)) {
+			fprintf(stderr, "Header bytes of %d are incorrect\n",
+				head->header_bytes);
+			continue;
+		}
+		if (count_lb_records(head) != head->table_entries) {
+			fprintf(stderr, "bad record count: %d\n",
+				head->table_entries);
+			continue;
+		}
+		if (compute_checksum((uint8_t *)head, sizeof(*head)) != 0) {
+			fprintf(stderr, "bad header checksum\n");
+			continue;
+		}
+		if (compute_checksum(recs, head->table_bytes)
+			!= head->table_checksum) {
+			fprintf(stderr, "bad table checksum: %04x\n",
+				head->table_checksum);
+			continue;
+		}
+		fprintf(stdout, "Found LinuxBIOS table at: %08lx\n", addr);
+		return head;
+
+	};
+	return 0;
+}
+
+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);
+	printf("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);
+
+	if(lb_part) {
+		printf("overwritten by command line, vendor id: %s part id: %s\n",
+				lb_vendor, lb_part);
+	} else {
+		lb_part=strdup(part);
+		lb_vendor=strdup(vendor);
+	}
+}
+
+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;
+		}
+	}
+}
+
+int linuxbios_init(void) 
+{
+	uint8_t *low_1MB;
+	struct lb_header *lb_table;
+	struct lb_record *rec, *last;
+	
+	int fd;
+	fd = open("/dev/mem", O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "Can not open /dev/mem\n");
+		exit(-1);
+	}
+	low_1MB = mmap(0, 1024*1024, PROT_READ, MAP_SHARED, fd, 0x00000000);
+	if (low_1MB == ((void *) -1)) {
+		fprintf(stderr, "Can not mmap /dev/mem at %08lx errno(%d):%s\n",
+			0x00000000UL, errno, strerror(errno));
+		exit(-2);
+	}
+	lb_table = 0;
+	if (!lb_table)
+		lb_table = find_lb_table(low_1MB, 0x00000, 0x1000);
+	if (!lb_table)
+		lb_table = find_lb_table(low_1MB, 0xf0000, 1024*1024);
+	if (lb_table) {
+		unsigned long addr;
+		addr = ((char *)lb_table) - ((char *)low_1MB);
+		printf_debug("lb_table found at address %p\n", lb_table);
+		rec  = (struct lb_record *)(((char *)lb_table) + lb_table->header_bytes);
+		last = (struct lb_record *)(((char *)rec) + lb_table->table_bytes);
+		printf_debug("LinuxBIOS 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);
+	}
+	else {
+		printf("No LinuxBIOS table found.\n");
+		return -1;
+	}
+	return 0;
+}