diff --git a/lib/sha256_common.c b/lib/sha256_common.c
new file mode 100644
index 0000000..7041abd
--- /dev/null
+++ b/lib/sha256_common.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * FIPS-180-2 compliant SHA-256 implementation
+ *
+ * Copyright (C) 2001-2003  Christophe Devine
+ */
+
+#ifndef USE_HOSTCC
+#include <u-boot/schedule.h>
+#endif /* USE_HOSTCC */
+#include <string.h>
+#include <u-boot/sha256.h>
+
+#include <linux/compiler_attributes.h>
+
+/*
+ * Output = SHA-256( input buffer ). Trigger the watchdog every 'chunk_sz'
+ * bytes of input processed.
+ */
+void sha256_csum_wd(const unsigned char *input, unsigned int ilen,
+		    unsigned char *output, unsigned int chunk_sz)
+{
+	sha256_context ctx;
+#if !defined(USE_HOSTCC) && \
+	(defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG))
+	const unsigned char *end;
+	unsigned char *curr;
+	int chunk;
+#endif
+
+	sha256_starts(&ctx);
+
+#if !defined(USE_HOSTCC) && \
+	(defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG))
+	curr = (unsigned char *)input;
+	end = input + ilen;
+	while (curr < end) {
+		chunk = end - curr;
+		if (chunk > chunk_sz)
+			chunk = chunk_sz;
+		sha256_update(&ctx, curr, chunk);
+		curr += chunk;
+		schedule();
+	}
+#else
+	sha256_update(&ctx, input, ilen);
+#endif
+
+	sha256_finish(&ctx, output);
+}