leverage flashrom fast partial read function to speed up VPD read.

include/lib/fmap.h

 /*
  * Copyright 2010, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *    * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 63 matching lines @@
   struct fmap_area {
     uint32_t offset;    /* offset relative to base */
     uint32_t size;      /* size in bytes */
     uint8_t  name[FMAP_STRLEN];  /* descriptive name */
     uint16_t flags;      /* flags for this area */
   }  __attribute__((packed)) areas[];
 } __attribute__((packed));
 
 /*
  * fmapNormalizeAreaName - to protect malicious attack, this function
- * replace all non-digits and non-alphabet chars into underline.
+ * replace not allowed chars into underline. Only following are allowed:
+ *
+ *   numbers
+ *   digits
+ *   space
+ *
+ * The allowing list should increase if fmap area name allows more chars.
  *
  * @name: point to the name.
  */
 void fmapNormalizeAreaName(uint8_t *name);
 
 
 /*
  * fmapFind - finds FMAP signature in a binary image
  *
  * @image:  binary image
@@ skipping 18 matching lines @@
  * @size: pointer to store the size of the found area.
  *
  * This function returns FMAP_OK if found. Returns FMAP_FAIL if not found.
  *
  */
 int fmapGetArea(const char *name, const struct fmap *fmap,
                 off_t *offset, off_t *size);
 
 
 #endif  /* __LIB_FMAP_H__*/