lib/check_signature.c

   1 #include <linux/io.h>
   2 #include <linux/module.h>
   3
   4 /**
   5  *      check_signature         -       find BIOS signatures
   6  *      @io_addr: mmio address to check
   7  *      @signature:  signature block
   8  *      @length: length of signature
   9  *
  10  *      Perform a signature comparison with the mmio address io_addr. This
  11  *      address should have been obtained by ioremap.
  12  *      Returns 1 on a match.
  13  */
  14
  15 int check_signature(const volatile void __iomem *io_addr,
  16                         const unsigned char *signature, int length)
  17 {
  18         while (length--) {
  19                 if (readb(io_addr) != *signature)
  20                         return 0;
  21                 io_addr++;
  22                 signature++;
  23         }
  24         return 1;
  25 }
  26 EXPORT_SYMBOL(check_signature);