LXR linux/lib/check

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/io.h>
   3#include <linux/export.h>
   4
   5/**
   6 *      check_signature         -       find BIOS signatures
   7 *      @io_addr: mmio address to check
   8 *      @signature:  signature block
   9 *      @length: length of signature
  10 *
  11 *      Perform a signature comparison with the mmio address io_addr. This
  12 *      address should have been obtained by ioremap.
  13 *      Returns 1 on a match.
  14 */
  15
  16int check_signature(const volatile void __iomem *io_addr,
  17                        const unsigned char *signature, int length)
  18{
  19        while (length--) {
  20                if (readb(io_addr) != *signature)
  21                        return 0;
  22                io_addr++;
  23                signature++;
  24        }
  25        return 1;
  26}
  27EXPORT_SYMBOL(check_signature);
  28