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