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 | |
16 | int check_signature(const volatile void __iomem *io_addr, |
17 | const unsigned char *signature, int length) |
18 | { |
19 | while (length--) { |
20 | if (readb(addr: io_addr) != *signature) |
21 | return 0; |
22 | io_addr++; |
23 | signature++; |
24 | } |
25 | return 1; |
26 | } |
27 | EXPORT_SYMBOL(check_signature); |
28 | |