libpayload: add memchr to libc

libfdt requires memchr. Add missing function to libc.

Change-Id: I872026559d16a352f350147c9d7c4be97456a99f
Signed-off-by: Philipp Hug <philipp@hug.cx>
Reviewed-on: https://review.coreboot.org/c/31354
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

2 files changed, 13 insertions, 0 deletions

diff --git a/payloads/libpayload/include/string.h b/payloads/libpayload/include/string.h
index ca5d5131e2..4aff0e8994 100644
--- a/payloads/libpayload/include/string.h
+++ b/payloads/libpayload/include/string.h
@@ -39,6 +39,7 @@
 void *memset(void *s, int c, size_t n);
 void *memcpy(void *dst, const void *src, size_t n);
 void *memmove(void *dst, const void *src, size_t n);
+void *memchr(const void *s, int c, size_t n);
 int memcmp(const void *s1, const void *s2, size_t len);
 /** @} */
 
diff --git a/payloads/libpayload/libc/memory.c b/payloads/libpayload/libc/memory.c
index 25c2b3af4f..8ee3eed9da 100644
--- a/payloads/libpayload/libc/memory.c
+++ b/payloads/libpayload/libc/memory.c
@@ -145,3 +145,15 @@ static int default_memcmp(const void *s1, const void *s2, size_t n)
 
 int memcmp(const void *s1, const void *s2, size_t n)
 	__attribute__((weak, alias("default_memcmp")));
+
+
+void *memchr(const void *s, int c, size_t n)
+{
+	unsigned char *p = (unsigned char *)s;
+	while (n--)
+		if (*p != (unsigned char)c)
+			p++;
+		else
+			return p;
+	return 0;
+}