libc: Import files from FreeBSD

From commit aafd1cf4235d78ce85b76d7da63e9589039344b3:

- sys/sys/endian.h
- sys/arm/include/endian.h
- sys/arm64/include/endian.h
- sys/sys/errno.h
- lib/libc/strchr.c
- lib/libc/strcmp.c
- lib/libc/strncmp.c
- lib/libc/strnlen.c

strcasecmp() hasn't been imported.

Change-Id: I8a0787aec9ba8960a008fb5c66f7a73c84919b93
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/include/lib/libc/aarch32/endian.h b/include/lib/libc/aarch32/endian.h
new file mode 100644
index 0000000..5fb94db
--- /dev/null
+++ b/include/lib/libc/aarch32/endian.h
@@ -0,0 +1,142 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 2001 David E. O'Brien
+ *
+ * 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.
+ * 3. 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.
+ *
+ *	@(#)endian.h	8.1 (Berkeley) 6/10/93
+ * $NetBSD: endian.h,v 1.7 1999/08/21 05:53:51 simonb Exp $
+ * $FreeBSD$
+ */
+
+#ifndef _ENDIAN_H_
+#define	_ENDIAN_H_
+
+#include <sys/_types.h>
+
+/*
+ * Definitions for byte order, according to byte significance from low
+ * address to high.
+ */
+#define _LITTLE_ENDIAN  1234    /* LSB first: i386, vax */
+#define _BIG_ENDIAN     4321    /* MSB first: 68000, ibm, net */
+#define _PDP_ENDIAN     3412    /* LSB first in word, MSW first in long */
+
+#ifdef __ARMEB__
+#define _BYTE_ORDER	_BIG_ENDIAN
+#else
+#define	_BYTE_ORDER	_LITTLE_ENDIAN
+#endif /* __ARMEB__ */
+
+#if __BSD_VISIBLE
+#define LITTLE_ENDIAN   _LITTLE_ENDIAN
+#define BIG_ENDIAN      _BIG_ENDIAN
+#define PDP_ENDIAN      _PDP_ENDIAN
+#define BYTE_ORDER      _BYTE_ORDER
+#endif
+
+#ifdef __ARMEB__
+#define _QUAD_HIGHWORD 0
+#define _QUAD_LOWWORD 1
+#define __ntohl(x)	((__uint32_t)(x))
+#define __ntohs(x)	((__uint16_t)(x))
+#define __htonl(x)	((__uint32_t)(x))
+#define __htons(x)	((__uint16_t)(x))
+#else
+#define _QUAD_HIGHWORD  1
+#define _QUAD_LOWWORD 0
+#define __ntohl(x)        (__bswap32(x))
+#define __ntohs(x)        (__bswap16(x))
+#define __htonl(x)        (__bswap32(x))
+#define __htons(x)        (__bswap16(x))
+#endif /* __ARMEB__ */
+
+static __inline __uint64_t
+__bswap64(__uint64_t _x)
+{
+
+	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
+	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
+	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
+	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
+}
+
+static __inline __uint32_t
+__bswap32_var(__uint32_t v)
+{
+	__uint32_t t1;
+
+	__asm __volatile("eor %1, %0, %0, ror #16\n"
+	    		"bic %1, %1, #0x00ff0000\n"
+			"mov %0, %0, ror #8\n"
+			"eor %0, %0, %1, lsr #8\n"
+			 : "+r" (v), "=r" (t1));
+
+	return (v);
+}
+
+static __inline __uint16_t
+__bswap16_var(__uint16_t v)
+{
+	__uint32_t ret = v & 0xffff;
+
+	__asm __volatile(
+	    "mov    %0, %0, ror #8\n"
+	    "orr    %0, %0, %0, lsr #16\n"
+	    "bic    %0, %0, %0, lsl #16"
+	    : "+r" (ret));
+
+	return ((__uint16_t)ret);
+}
+
+#ifdef __OPTIMIZE__
+
+#define __bswap32_constant(x)	\
+    ((((x) & 0xff000000U) >> 24) |	\
+     (((x) & 0x00ff0000U) >>  8) |	\
+     (((x) & 0x0000ff00U) <<  8) |	\
+     (((x) & 0x000000ffU) << 24))
+
+#define __bswap16_constant(x)	\
+    ((((x) & 0xff00) >> 8) |		\
+     (((x) & 0x00ff) << 8))
+
+#define __bswap16(x)	\
+    ((__uint16_t)(__builtin_constant_p(x) ?	\
+     __bswap16_constant(x) :			\
+     __bswap16_var(x)))
+
+#define __bswap32(x)	\
+    ((__uint32_t)(__builtin_constant_p(x) ? 	\
+     __bswap32_constant(x) :			\
+     __bswap32_var(x)))
+
+#else
+#define __bswap16(x)	__bswap16_var(x)
+#define __bswap32(x)	__bswap32_var(x)
+
+#endif /* __OPTIMIZE__ */
+#endif /* !_ENDIAN_H_ */
diff --git a/include/lib/libc/aarch64/endian.h b/include/lib/libc/aarch64/endian.h
new file mode 100644
index 0000000..52b9a32
--- /dev/null
+++ b/include/lib/libc/aarch64/endian.h
@@ -0,0 +1,122 @@
+/*-
+ * Copyright (c) 2001 David E. O'Brien
+ *
+ * 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.
+ * 3. 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.
+ *
+ *	@(#)endian.h	8.1 (Berkeley) 6/10/93
+ * $NetBSD: endian.h,v 1.7 1999/08/21 05:53:51 simonb Exp $
+ * $FreeBSD$
+ */
+
+#ifndef _MACHINE_ENDIAN_H_
+#define	_MACHINE_ENDIAN_H_
+
+#include <sys/_types.h>
+
+/*
+ * Definitions for byte order, according to byte significance from low
+ * address to high.
+ */
+#define	_LITTLE_ENDIAN  1234    /* LSB first: i386, vax */
+#define	_BIG_ENDIAN     4321    /* MSB first: 68000, ibm, net */
+#define	_PDP_ENDIAN     3412    /* LSB first in word, MSW first in long */
+
+#define	_BYTE_ORDER	_LITTLE_ENDIAN
+
+#if __BSD_VISIBLE
+#define	LITTLE_ENDIAN   _LITTLE_ENDIAN
+#define	BIG_ENDIAN      _BIG_ENDIAN
+#define	PDP_ENDIAN      _PDP_ENDIAN
+#define	BYTE_ORDER      _BYTE_ORDER
+#endif
+
+#define	_QUAD_HIGHWORD  1
+#define	_QUAD_LOWWORD 0
+#define	__ntohl(x)        (__bswap32(x))
+#define	__ntohs(x)        (__bswap16(x))
+#define	__htonl(x)        (__bswap32(x))
+#define	__htons(x)        (__bswap16(x))
+
+static __inline __uint64_t
+__bswap64(__uint64_t x)
+{
+	__uint64_t ret;
+
+	__asm __volatile("rev %0, %1\n"
+			 : "=&r" (ret), "+r" (x));
+	
+	return (ret);
+}
+
+static __inline __uint32_t
+__bswap32_var(__uint32_t v)
+{
+	__uint32_t ret;
+
+	__asm __volatile("rev32 %x0, %x1\n"
+			 : "=&r" (ret), "+r" (v));
+	
+	return (ret);
+}
+
+static __inline __uint16_t
+__bswap16_var(__uint16_t v)
+{
+	__uint32_t ret;
+
+	__asm __volatile("rev16 %w0, %w1\n"
+			 : "=&r" (ret), "+r" (v));
+
+	return ((__uint16_t)ret);
+}		
+
+#ifdef __OPTIMIZE__
+
+#define	__bswap32_constant(x)	\
+    ((((x) & 0xff000000U) >> 24) |	\
+     (((x) & 0x00ff0000U) >>  8) |	\
+     (((x) & 0x0000ff00U) <<  8) |	\
+     (((x) & 0x000000ffU) << 24))
+
+#define	__bswap16_constant(x)	\
+    ((((x) & 0xff00) >> 8) |		\
+     (((x) & 0x00ff) << 8))
+
+#define	__bswap16(x)	\
+    ((__uint16_t)(__builtin_constant_p(x) ?	\
+     __bswap16_constant((__uint16_t)(x)) :	\
+     __bswap16_var(x)))
+
+#define	__bswap32(x)	\
+    ((__uint32_t)(__builtin_constant_p(x) ? 	\
+     __bswap32_constant((__uint32_t)(x)) :	\
+     __bswap32_var(x)))
+
+#else
+#define	__bswap16(x)	__bswap16_var(x)
+#define	__bswap32(x)	__bswap32_var(x)
+
+#endif /* __OPTIMIZE__ */
+#endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/include/lib/libc/endian.h b/include/lib/libc/endian.h
new file mode 100644
index 0000000..3cef613
--- /dev/null
+++ b/include/lib/libc/endian.h
@@ -0,0 +1,207 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2002 Thomas Moestl <tmm@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_ENDIAN_H_
+#define _SYS_ENDIAN_H_
+
+#include <sys/cdefs.h>
+#include <sys/_types.h>
+#include <machine/endian.h>
+
+#ifndef _UINT8_T_DECLARED
+typedef	__uint8_t	uint8_t;
+#define	_UINT8_T_DECLARED
+#endif
+ 
+#ifndef _UINT16_T_DECLARED
+typedef	__uint16_t	uint16_t;
+#define	_UINT16_T_DECLARED
+#endif
+ 
+#ifndef _UINT32_T_DECLARED
+typedef	__uint32_t	uint32_t;
+#define	_UINT32_T_DECLARED
+#endif
+ 
+#ifndef _UINT64_T_DECLARED
+typedef	__uint64_t	uint64_t;
+#define	_UINT64_T_DECLARED
+#endif
+ 
+/*
+ * General byte order swapping functions.
+ */
+#define	bswap16(x)	__bswap16(x)
+#define	bswap32(x)	__bswap32(x)
+#define	bswap64(x)	__bswap64(x)
+
+/*
+ * Host to big endian, host to little endian, big endian to host, and little
+ * endian to host byte order functions as detailed in byteorder(9).
+ */
+#if _BYTE_ORDER == _LITTLE_ENDIAN
+#define	htobe16(x)	bswap16((x))
+#define	htobe32(x)	bswap32((x))
+#define	htobe64(x)	bswap64((x))
+#define	htole16(x)	((uint16_t)(x))
+#define	htole32(x)	((uint32_t)(x))
+#define	htole64(x)	((uint64_t)(x))
+
+#define	be16toh(x)	bswap16((x))
+#define	be32toh(x)	bswap32((x))
+#define	be64toh(x)	bswap64((x))
+#define	le16toh(x)	((uint16_t)(x))
+#define	le32toh(x)	((uint32_t)(x))
+#define	le64toh(x)	((uint64_t)(x))
+#else /* _BYTE_ORDER != _LITTLE_ENDIAN */
+#define	htobe16(x)	((uint16_t)(x))
+#define	htobe32(x)	((uint32_t)(x))
+#define	htobe64(x)	((uint64_t)(x))
+#define	htole16(x)	bswap16((x))
+#define	htole32(x)	bswap32((x))
+#define	htole64(x)	bswap64((x))
+
+#define	be16toh(x)	((uint16_t)(x))
+#define	be32toh(x)	((uint32_t)(x))
+#define	be64toh(x)	((uint64_t)(x))
+#define	le16toh(x)	bswap16((x))
+#define	le32toh(x)	bswap32((x))
+#define	le64toh(x)	bswap64((x))
+#endif /* _BYTE_ORDER == _LITTLE_ENDIAN */
+
+/* Alignment-agnostic encode/decode bytestream to/from little/big endian. */
+
+static __inline uint16_t
+be16dec(const void *pp)
+{
+	uint8_t const *p = (uint8_t const *)pp;
+
+	return ((p[0] << 8) | p[1]);
+}
+
+static __inline uint32_t
+be32dec(const void *pp)
+{
+	uint8_t const *p = (uint8_t const *)pp;
+
+	return (((unsigned)p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
+}
+
+static __inline uint64_t
+be64dec(const void *pp)
+{
+	uint8_t const *p = (uint8_t const *)pp;
+
+	return (((uint64_t)be32dec(p) << 32) | be32dec(p + 4));
+}
+
+static __inline uint16_t
+le16dec(const void *pp)
+{
+	uint8_t const *p = (uint8_t const *)pp;
+
+	return ((p[1] << 8) | p[0]);
+}
+
+static __inline uint32_t
+le32dec(const void *pp)
+{
+	uint8_t const *p = (uint8_t const *)pp;
+
+	return (((unsigned)p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0]);
+}
+
+static __inline uint64_t
+le64dec(const void *pp)
+{
+	uint8_t const *p = (uint8_t const *)pp;
+
+	return (((uint64_t)le32dec(p + 4) << 32) | le32dec(p));
+}
+
+static __inline void
+be16enc(void *pp, uint16_t u)
+{
+	uint8_t *p = (uint8_t *)pp;
+
+	p[0] = (u >> 8) & 0xff;
+	p[1] = u & 0xff;
+}
+
+static __inline void
+be32enc(void *pp, uint32_t u)
+{
+	uint8_t *p = (uint8_t *)pp;
+
+	p[0] = (u >> 24) & 0xff;
+	p[1] = (u >> 16) & 0xff;
+	p[2] = (u >> 8) & 0xff;
+	p[3] = u & 0xff;
+}
+
+static __inline void
+be64enc(void *pp, uint64_t u)
+{
+	uint8_t *p = (uint8_t *)pp;
+
+	be32enc(p, (uint32_t)(u >> 32));
+	be32enc(p + 4, (uint32_t)(u & 0xffffffffU));
+}
+
+static __inline void
+le16enc(void *pp, uint16_t u)
+{
+	uint8_t *p = (uint8_t *)pp;
+
+	p[0] = u & 0xff;
+	p[1] = (u >> 8) & 0xff;
+}
+
+static __inline void
+le32enc(void *pp, uint32_t u)
+{
+	uint8_t *p = (uint8_t *)pp;
+
+	p[0] = u & 0xff;
+	p[1] = (u >> 8) & 0xff;
+	p[2] = (u >> 16) & 0xff;
+	p[3] = (u >> 24) & 0xff;
+}
+
+static __inline void
+le64enc(void *pp, uint64_t u)
+{
+	uint8_t *p = (uint8_t *)pp;
+
+	le32enc(p, (uint32_t)(u & 0xffffffffU));
+	le32enc(p + 4, (uint32_t)(u >> 32));
+}
+
+#endif	/* _SYS_ENDIAN_H_ */
diff --git a/include/lib/libc/errno.h b/include/lib/libc/errno.h
new file mode 100644
index 0000000..ad140ab
--- /dev/null
+++ b/include/lib/libc/errno.h
@@ -0,0 +1,208 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1982, 1986, 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * 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.
+ * 3. 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.
+ *
+ *	@(#)errno.h	8.5 (Berkeley) 1/21/94
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_ERRNO_H_
+#define _SYS_ERRNO_H_
+
+#if !defined(_KERNEL) && !defined(_STANDALONE)
+#include <sys/cdefs.h>
+__BEGIN_DECLS
+int *	__error(void);
+__END_DECLS
+#define	errno		(* __error())
+#endif
+
+#define	EPERM		1		/* Operation not permitted */
+#define	ENOENT		2		/* No such file or directory */
+#define	ESRCH		3		/* No such process */
+#define	EINTR		4		/* Interrupted system call */
+#define	EIO		5		/* Input/output error */
+#define	ENXIO		6		/* Device not configured */
+#define	E2BIG		7		/* Argument list too long */
+#define	ENOEXEC		8		/* Exec format error */
+#define	EBADF		9		/* Bad file descriptor */
+#define	ECHILD		10		/* No child processes */
+#define	EDEADLK		11		/* Resource deadlock avoided */
+					/* 11 was EAGAIN */
+#define	ENOMEM		12		/* Cannot allocate memory */
+#define	EACCES		13		/* Permission denied */
+#define	EFAULT		14		/* Bad address */
+#ifndef _POSIX_SOURCE
+#define	ENOTBLK		15		/* Block device required */
+#endif
+#define	EBUSY		16		/* Device busy */
+#define	EEXIST		17		/* File exists */
+#define	EXDEV		18		/* Cross-device link */
+#define	ENODEV		19		/* Operation not supported by device */
+#define	ENOTDIR		20		/* Not a directory */
+#define	EISDIR		21		/* Is a directory */
+#define	EINVAL		22		/* Invalid argument */
+#define	ENFILE		23		/* Too many open files in system */
+#define	EMFILE		24		/* Too many open files */
+#define	ENOTTY		25		/* Inappropriate ioctl for device */
+#ifndef _POSIX_SOURCE
+#define	ETXTBSY		26		/* Text file busy */
+#endif
+#define	EFBIG		27		/* File too large */
+#define	ENOSPC		28		/* No space left on device */
+#define	ESPIPE		29		/* Illegal seek */
+#define	EROFS		30		/* Read-only filesystem */
+#define	EMLINK		31		/* Too many links */
+#define	EPIPE		32		/* Broken pipe */
+
+/* math software */
+#define	EDOM		33		/* Numerical argument out of domain */
+#define	ERANGE		34		/* Result too large */
+
+/* non-blocking and interrupt i/o */
+#define	EAGAIN		35		/* Resource temporarily unavailable */
+#ifndef _POSIX_SOURCE
+#define	EWOULDBLOCK	EAGAIN		/* Operation would block */
+#define	EINPROGRESS	36		/* Operation now in progress */
+#define	EALREADY	37		/* Operation already in progress */
+
+/* ipc/network software -- argument errors */
+#define	ENOTSOCK	38		/* Socket operation on non-socket */
+#define	EDESTADDRREQ	39		/* Destination address required */
+#define	EMSGSIZE	40		/* Message too long */
+#define	EPROTOTYPE	41		/* Protocol wrong type for socket */
+#define	ENOPROTOOPT	42		/* Protocol not available */
+#define	EPROTONOSUPPORT	43		/* Protocol not supported */
+#define	ESOCKTNOSUPPORT	44		/* Socket type not supported */
+#define	EOPNOTSUPP	45		/* Operation not supported */
+#define	ENOTSUP		EOPNOTSUPP	/* Operation not supported */
+#define	EPFNOSUPPORT	46		/* Protocol family not supported */
+#define	EAFNOSUPPORT	47		/* Address family not supported by protocol family */
+#define	EADDRINUSE	48		/* Address already in use */
+#define	EADDRNOTAVAIL	49		/* Can't assign requested address */
+
+/* ipc/network software -- operational errors */
+#define	ENETDOWN	50		/* Network is down */
+#define	ENETUNREACH	51		/* Network is unreachable */
+#define	ENETRESET	52		/* Network dropped connection on reset */
+#define	ECONNABORTED	53		/* Software caused connection abort */
+#define	ECONNRESET	54		/* Connection reset by peer */
+#define	ENOBUFS		55		/* No buffer space available */
+#define	EISCONN		56		/* Socket is already connected */
+#define	ENOTCONN	57		/* Socket is not connected */
+#define	ESHUTDOWN	58		/* Can't send after socket shutdown */
+#define	ETOOMANYREFS	59		/* Too many references: can't splice */
+#define	ETIMEDOUT	60		/* Operation timed out */
+#define	ECONNREFUSED	61		/* Connection refused */
+
+#define	ELOOP		62		/* Too many levels of symbolic links */
+#endif /* _POSIX_SOURCE */
+#define	ENAMETOOLONG	63		/* File name too long */
+
+/* should be rearranged */
+#ifndef _POSIX_SOURCE
+#define	EHOSTDOWN	64		/* Host is down */
+#define	EHOSTUNREACH	65		/* No route to host */
+#endif /* _POSIX_SOURCE */
+#define	ENOTEMPTY	66		/* Directory not empty */
+
+/* quotas & mush */
+#ifndef _POSIX_SOURCE
+#define	EPROCLIM	67		/* Too many processes */
+#define	EUSERS		68		/* Too many users */
+#define	EDQUOT		69		/* Disc quota exceeded */
+
+/* Network File System */
+#define	ESTALE		70		/* Stale NFS file handle */
+#define	EREMOTE		71		/* Too many levels of remote in path */
+#define	EBADRPC		72		/* RPC struct is bad */
+#define	ERPCMISMATCH	73		/* RPC version wrong */
+#define	EPROGUNAVAIL	74		/* RPC prog. not avail */
+#define	EPROGMISMATCH	75		/* Program version wrong */
+#define	EPROCUNAVAIL	76		/* Bad procedure for program */
+#endif /* _POSIX_SOURCE */
+
+#define	ENOLCK		77		/* No locks available */
+#define	ENOSYS		78		/* Function not implemented */
+
+#ifndef _POSIX_SOURCE
+#define	EFTYPE		79		/* Inappropriate file type or format */
+#define	EAUTH		80		/* Authentication error */
+#define	ENEEDAUTH	81		/* Need authenticator */
+#define	EIDRM		82		/* Identifier removed */
+#define	ENOMSG		83		/* No message of desired type */
+#define	EOVERFLOW	84		/* Value too large to be stored in data type */
+#define	ECANCELED	85		/* Operation canceled */
+#define	EILSEQ		86		/* Illegal byte sequence */
+#define	ENOATTR		87		/* Attribute not found */
+
+#define	EDOOFUS		88		/* Programming error */
+#endif /* _POSIX_SOURCE */
+
+#define	EBADMSG		89		/* Bad message */
+#define	EMULTIHOP	90		/* Multihop attempted */
+#define	ENOLINK		91		/* Link has been severed */
+#define	EPROTO		92		/* Protocol error */
+
+#ifndef _POSIX_SOURCE
+#define	ENOTCAPABLE	93		/* Capabilities insufficient */
+#define	ECAPMODE	94		/* Not permitted in capability mode */
+#define	ENOTRECOVERABLE	95		/* State not recoverable */
+#define	EOWNERDEAD	96		/* Previous owner died */
+#endif /* _POSIX_SOURCE */
+
+#ifndef _POSIX_SOURCE
+#define	ELAST		96		/* Must be equal largest errno */
+#endif /* _POSIX_SOURCE */
+
+#if defined(_KERNEL) || defined(_WANT_KERNEL_ERRNO)
+/* pseudo-errors returned inside kernel to modify return to process */
+#define	ERESTART	(-1)		/* restart syscall */
+#define	EJUSTRETURN	(-2)		/* don't modify regs, just return */
+#define	ENOIOCTL	(-3)		/* ioctl not handled by this layer */
+#define	EDIRIOCTL	(-4)		/* do direct ioctl in GEOM */
+#define	ERELOOKUP	(-5)		/* retry the directory lookup */
+#endif
+
+#ifndef _KERNEL
+#if __EXT1_VISIBLE
+/* ISO/IEC 9899:2011 K.3.2.2 */
+#ifndef _ERRNO_T_DEFINED
+#define _ERRNO_T_DEFINED
+typedef int errno_t;
+#endif
+#endif /* __EXT1_VISIBLE */
+#endif
+
+#endif
diff --git a/lib/libc/strchr.c b/lib/libc/strchr.c
new file mode 100644
index 0000000..61244da
--- /dev/null
+++ b/lib/libc/strchr.c
@@ -0,0 +1,56 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ * 3. 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)index.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stddef.h>
+#include <string.h>
+
+char *
+strchr(const char *p, int ch)
+{
+	char c;
+
+	c = ch;
+	for (;; ++p) {
+		if (*p == c)
+			return ((char *)p);
+		if (*p == '\0')
+			return (NULL);
+	}
+	/* NOTREACHED */
+}
+
+__weak_reference(strchr, index);
diff --git a/lib/libc/strcmp.c b/lib/libc/strcmp.c
new file mode 100644
index 0000000..63cb446
--- /dev/null
+++ b/lib/libc/strcmp.c
@@ -0,0 +1,53 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * 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.
+ * 3. 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)strcmp.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <string.h>
+
+/*
+ * Compare strings.
+ */
+int
+strcmp(const char *s1, const char *s2)
+{
+	while (*s1 == *s2++)
+		if (*s1++ == '\0')
+			return (0);
+	return (*(const unsigned char *)s1 - *(const unsigned char *)(s2 - 1));
+}
diff --git a/lib/libc/strncmp.c b/lib/libc/strncmp.c
new file mode 100644
index 0000000..c68fe00
--- /dev/null
+++ b/lib/libc/strncmp.c
@@ -0,0 +1,54 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ * 3. 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)strncmp.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <string.h>
+
+int
+strncmp(const char *s1, const char *s2, size_t n)
+{
+
+	if (n == 0)
+		return (0);
+	do {
+		if (*s1 != *s2++)
+			return (*(const unsigned char *)s1 -
+				*(const unsigned char *)(s2 - 1));
+		if (*s1++ == '\0')
+			break;
+	} while (--n != 0);
+	return (0);
+}
diff --git a/lib/libc/strnlen.c b/lib/libc/strnlen.c
new file mode 100644
index 0000000..fca7ad2
--- /dev/null
+++ b/lib/libc/strnlen.c
@@ -0,0 +1,44 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <string.h>
+
+size_t
+strnlen(const char *s, size_t maxlen)
+{
+	size_t len;
+
+	for (len = 0; len < maxlen; len++, s++) {
+		if (!*s)
+			break;
+	}
+	return (len);
+}