lib: add libc and micro libc

lib/ulibc/string/memcpy.c

@@ -0,0 +1,107 @@
+/*-
+ * Copyright (c) 1990, 1993
+ *  The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#include <stddef.h>
+#include <stdint.h>
+
+typedef uintptr_t word;
+#define wsize sizeof(word)
+#define wmask (wsize - 1)
+
+void *memcpy(void *dst0, const void *src0, size_t length)
+{
+	char *dst = dst0;
+	const char *src = src0;
+	size_t t;
+
+	if (length == 0 || dst == src) /* nothing to do */
+		goto done;
+
+	/*
+	 * Macros: loop-t-times; and loop-t-times, t>0
+	 */
+#define TLOOP(s)                                                               \
+	if (t)                                                                 \
+	TLOOP1(s)
+#define TLOOP1(s)                                                              \
+	do {                                                                   \
+		s;                                                             \
+	} while (--t)
+
+	if ((uintptr_t)dst < (uintptr_t)src) {
+		/*
+		 * Copy forward.
+		 */
+		t = (uintptr_t)src; /* only need low bits */
+		if ((t | (uintptr_t)dst) & wmask) {
+			/*
+			 * Try to align operands.  This cannot be done
+			 * unless the low bits match.
+			 */
+			if ((t ^ (uintptr_t)dst) & wmask || length < wsize)
+				t = length;
+			else
+				t = wsize - (t & wmask);
+			length -= t;
+			TLOOP1(*dst++ = *src++);
+		}
+		/*
+		 * Copy whole words, then mop up any trailing bytes.
+		 */
+		t = length / wsize;
+		TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize);
+		t = length & wmask;
+		TLOOP(*dst++ = *src++);
+	} else {
+		/*
+		 * Copy backwards.  Otherwise essentially the same.
+		 * Alignment works as before, except that it takes
+		 * (t&wmask) bytes to align, not wsize-(t&wmask).
+		 */
+		src += length;
+		dst += length;
+		t = (uintptr_t)src;
+		if ((t | (uintptr_t)dst) & wmask) {
+			if ((t ^ (uintptr_t)dst) & wmask || length <= wsize)
+				t = length;
+			else
+				t &= wmask;
+			length -= t;
+			TLOOP1(*--dst = *--src);
+		}
+		t = length / wsize;
+		TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src);
+		t = length & wmask;
+		TLOOP(*--dst = *--src);
+	}
+done:
+	return (dst0);
+}

lib/ulibc/string/memset.c

@@ -0,0 +1,13 @@
+#include <stddef.h>
+
+void *memset(void *str, int c, size_t n)
+{
+	unsigned char val = (unsigned char)c;
+	unsigned char *buf = str;
+
+	for (size_t i = 0; i < n; i++) {
+		buf[i] = val;
+	}
+
+	return str;
+}

lib/ulibc/string/strcmp.c

@@ -0,0 +1,21 @@
+int strcmp(const char *s1, const char *s2)
+{
+	int i;
+	for (i = 0; s1[i] == s2[i]; i++)
+		if (s1[i] == '\0')
+			return 0;
+
+	return s1[i] - s2[i];
+}
+
+int strncmp(const char *s1, const char *s2, unsigned long n)
+{
+	for (; n > 0; s1++, s2++, --n)
+		if (*s1 != *s2)
+			return ((*(unsigned char *)s1 < *(unsigned char *)s2)
+			                ? -1
+			                : 1);
+		else if (*s1 == '\0')
+			return 0;
+	return 0;
+}

lib/ulibc/string/strlen.c

@@ -0,0 +1,11 @@
+#include <string.h>
+
+size_t strlen(const char *str)
+{
+	size_t res = 0;
+	while (str[res]) {
+		res++;
+	}
+
+	return res;
+}