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-rw-r--r--lbtable.c193
1 files changed, 193 insertions, 0 deletions
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;
+}
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