Changeset 3408 for trunk/util/flashrom/layout.c

Timestamp:

07/03/08 16:40:06 (5 months ago)

Author:

hailfinger

Message:

Improve coreboot image detection heuristic in flashrom. It's not
absolutely perfect, but the likelihood of this check to fail is
0.000000000000000000000000013 (1.3*10^{-26) which is good enough for me.}

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@…>
Acked-by: Stefan Reinauer <stepan@…>

Files:

• trunk/util/flashrom/layout.c (modified) (2 diffs)

trunk/util/flashrom/layout.c

@@ -22 +22 @@
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
 #include <stdint.h>
 #include "flash.h"
@@ -58 +59 @@
         }
 
-        if ((*walk) == 0 || ((*walk) & 0x3ff) != 0) {
+        /*
+         * 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).
+         */
+        if ((*walk) == 0 || ((*walk) & 0x3ff) != 0 || *walk > size ||
+                *(walk - 1) > size || *(walk - 2) > size ||
+                (!isprint((const char *)(bios + size - *(walk - 1))) &&
+                ((const char *)(bios + size - *(walk - 1)))) ||
+                (!isprint((const char *)(bios + size - *(walk - 2))) &&
+                ((const char *)(bios + size - *(walk - 2))))) {
                 printf("Flash image seems to be a legacy BIOS. Disabling checks.\n");
                 mainboard_vendor = def_name;