[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/lib/check_signature.c b/ap/os/linux/linux-3.4.x/lib/check_signature.c
new file mode 100644
index 0000000..6b49797
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/lib/check_signature.c
@@ -0,0 +1,26 @@
+#include <linux/io.h>
+#include <linux/export.h>
+
+/**
+ * check_signature - find BIOS signatures
+ * @io_addr: mmio address to check
+ * @signature: signature block
+ * @length: length of signature
+ *
+ * Perform a signature comparison with the mmio address io_addr. This
+ * address should have been obtained by ioremap.
+ * Returns 1 on a match.
+ */
+
+int check_signature(const volatile void __iomem *io_addr,
+ const unsigned char *signature, int length)
+{
+ while (length--) {
+ if (readb(io_addr) != *signature)
+ return 0;
+ io_addr++;
+ signature++;
+ }
+ return 1;
+}
+EXPORT_SYMBOL(check_signature);