7 files changed, 124 insertions, 0 deletions
diff --git a/lib/libc/Makefile b/lib/libc/Makefile
new file mode 100644
index 0000000..b2aea30
--- /dev/null
+++ b/lib/libc/Makefile
@@ -0,0 +1,25 @@
+BUILDDIR=build/${TARGET}
+TARGETDIR=../../mainboard/${TARGET}
+
+.if !exists(${TARGETDIR}/conf/mainboard.conf)
+.error 'ERROR: invalid target "${TARGET}"'
+.else
+.include <${TARGETDIR}/conf/mainboard.conf>
+.endif
+
+SRC=\
+    string/memcpy.c \
+    string/memmove.c \
+    string/memset.c \
+    string/memcmp.c \
+    string/memchr.c \
+
+
+${BUILDDIR}/libc.a: ${SRC}
+	mkdir -p ${BUILDDIR}
+	cd ${BUILDDIR} && ${CROSS_COMPILE}gcc -c ${CFLAGS} ${SRC:%=../../%}
+	cd ${BUILDDIR} && ${CROSS_COMPILE}ar -rcs ${@:T} ${SRC:T:%.c=%.o}
+
+
+clean:
+	rm -rf ${BUILDDIR}
diff --git a/lib/libc/string/memchr.c b/lib/libc/string/memchr.c
new file mode 100644
index 0000000..9da3265
--- /dev/null
+++ b/lib/libc/string/memchr.c
@@ -0,0 +1,11 @@
+#include <string.h>
+
+void *memchr(const void *s, int c, size_t n) {
+	const char *p = s;
+	while (n--) {
+		if ((char)c == *p++) {
+			return (void*)(p-1);
+		}
+	}
+	return NULL;
+}
diff --git a/lib/libc/string/memcmp.c b/lib/libc/string/memcmp.c
new file mode 100644
index 0000000..a3d47fb
--- /dev/null
+++ b/lib/libc/string/memcmp.c
@@ -0,0 +1,15 @@
+#include <string.h>
+
+int 
+memcmp(const void *s1, const void *s2, size_t n)
+{
+	const char *str1 = (const char *)s1;
+	const char *str2 = (const char *)s2;
+	while (n--) {
+		if (*str1 != *str2)
+			return *str1 - *str2;
+		str1++; str2++;
+	}
+	return 0;
+}
+
diff --git a/lib/libc/string/memcpy.c b/lib/libc/string/memcpy.c
new file mode 100644
index 0000000..7573c01
--- /dev/null
+++ b/lib/libc/string/memcpy.c
@@ -0,0 +1,11 @@
+#include <string.h>
+
+void *memcpy(void *__restrict s1, const void *__restrict s2, size_t n)
+{
+	char *tmp = s1;
+	const char *s = s2;
+
+	while (n--)
+		*tmp++ = *s++;
+	return s1;
+}
diff --git a/lib/libc/string/memmove.c b/lib/libc/string/memmove.c
new file mode 100644
index 0000000..16be329
--- /dev/null
+++ b/lib/libc/string/memmove.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/lib/string.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+#include <string.h>
+
+void *memmove(void *dest, const void *src, size_t count)
+{
+	char *tmp;
+	const char *s;
+
+	if (dest <= src) {
+		tmp = dest;
+		s = src;
+		while (count--)
+			*tmp++ = *s++;
+	} else {
+		tmp = dest;
+		tmp += count;
+		s = src;
+		s += count;
+		while (count--)
+			*--tmp = *--s;
+	}
+	return dest;
+}
diff --git a/lib/libc/string/memset.c b/lib/libc/string/memset.c
new file mode 100644
index 0000000..59e3bea
--- /dev/null
+++ b/lib/libc/string/memset.c
@@ -0,0 +1,14 @@
+#include <stddef.h>
+#include <string.h>
+
+void *
+memset(void *s, int c, size_t n)
+{
+	char *xs = s;
+
+	while (n--)
+		*xs++ = c;
+
+	return s;
+}
+
diff --git a/lib/libc/string/strchr.c b/lib/libc/string/strchr.c
new file mode 100644
index 0000000..09b4d43
--- /dev/null
+++ b/lib/libc/string/strchr.c
@@ -0,0 +1,20 @@
+#include <string.h>
+
+char *strchr(const char *s, int c) {
+	do {
+		if ((char)c == *s) {
+			return (char*)s;
+		}
+	} while (*s++ != '\0');
+	return NULL;
+}
+
+char *strrchr(const char *s, int c)
+{
+	const char *last = NULL;
+	do {
+		if (*s == (char)c)
+			last = s;
+	} while (*s++);
+	return (char *)last;
+}