tashaboot: arm64 bootloader

A small arm64 bootloader. No board code, no device tree porting, the
architecture manual is the whole story: exception vectors in the
fixed 16 slot layout (Table D1-7), ESR_ELx decoded by exception class
(D1-2172), EL entry and eret chains per the programmers model
(D1-2146), cache maintenance by set/way over the CLIDR_EL1 levels,
semihosting for console and file io per DUI 0203, and the A64 boot
protocol from Documentation/arch/arm64/booting.rst.

The loader boots a stock mainline Image end to end on the qemu virt
machine. Boot receipt with 7.3-rc3 (42MB Image):

  tashaboot 0.1
  loaded 43450368 bytes at 40200000, entry 40200000
  jumping
  [    0.000000] Booting Linux on physical CPU 0x0000000000 [0x411fd070]
  [    0.000000] Linux version 7.3.0-rc3
  [    0.000000] Machine model: linux,dummy-virt
  [    0.000000] earlycon: pl11 MMIO32:0x0000000009000000
  ...
  ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs ]---

The panic is the expected end state, no root filesystem is handed
over yet.

The boot chain, state per stage, start to payload:

+-----------+-----+--------------+----------------------------------+
| stage     | EL  | state        | work                             |
+-----------+-----+--------------+----------------------------------+
| firmware  | any | MMU maybe on | x0 = dtb, jump in               |
+-----------+-----+--------------+----------------------------------+
| tashaboot | 3-2 |              | SCR_EL3.NS = 1, eret to EL2     |
+-----------+-----+--------------+----------------------------------+
|           | 2   | virt scrub   | HCR/CNTHCTL/CPTR/HSTR, CNTFRQ,  |
|           |     |              | VBAR_EL2, MMU off, tlbi alle2   |
+-----------+-----+--------------+----------------------------------+
|           | 2   |              | load Image over semihosting,    |
|           |     |              | validate header, place per      |
|           |     |              | booting.rst                     |
+-----------+-----+--------------+----------------------------------+
|           | 2   | caches clean | flush dcache, inval icache,     |
|           |     |              | args ride x20/x21, regs last    |
+-----------+-----+--------------+----------------------------------+
| payload   | 2   | fresh start  | x0 = dtb, x1-x3 = 0, DAIF       |
|           |     |              | masked, br to image entry       |
+-----------+-----+--------------+----------------------------------+

Two handoff bugs the kernel caught, both AAPCS clobbers in the final
jump. Cache maintenance was called after the register setup, x0-x18
are caller saved, so tb_flush_dcache_all() wiped the dtb pointer and
the kernel spun in setup_machine_fdt() with an invalid device tree
blob. The flush helpers also clobbered x1 (u-boot's void call
convention left mov x1, x0 in cache.S) which handed the kernel a wild
x0. The arguments ride in x20/x21 across the cache calls now, callee
saved, and the register setup is the last thing before the branch.

What is missing on purpose: no SMP bringup (secondary cores park),
no PSCI, no initrd or root filesystem handoff, single serial
console. Those come next.

Signed-off-by: Bradley Morgan <brads@mainlining.org>

21 files changed, 1467 insertions, 0 deletions

diff --git a/lib/itoa.c b/lib/itoa.c
new file mode 100644
index 0000000..4fc2db6
--- /dev/null
+++ b/lib/itoa.c
@@ -0,0 +1,63 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * * Redistributions of source code must retain the above copyright
+ *  notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *   * Neither the name of The Linux Foundation 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 "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER 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.
+*/
+
+/* freestanding, no stdlib */
+#include <string.h>
+#include <ctype.h>
+
+int
+itoa(int num, unsigned char* str, int len, int base)
+{
+	int sum = num;
+	int i = 0;
+	int digit;
+
+	if (len == 0)
+		return -1;
+
+	do
+	{
+		digit = sum % base;
+
+		if (digit < 0xA)
+			str[i++] = '0' + digit;
+		else
+			str[i++] = 'A' + digit - 0xA;
+
+		sum /= base;
+
+	}while (sum && (i < (len - 1)));
+
+	if (i == (len - 1) && sum)
+		return -1;
+
+	str[i] = '\0';
+	strrev(str);
+
+	return 0;
+}
diff --git a/lib/printf.c b/lib/printf.c
new file mode 100644
index 0000000..14fa452
--- /dev/null
+++ b/lib/printf.c
@@ -0,0 +1,383 @@
+/*
+ * Copyright (c) 2008-2013 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <debug.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <printf.h>
+#include <string.h>
+
+int printf(const char *fmt, ...)
+{
+	int err;
+
+	va_list ap;
+	va_start(ap, fmt);
+	err = _dvprintf(fmt, ap);
+	va_end(ap);
+
+	return err;
+}
+
+int sprintf(char *str, const char *fmt, ...)
+{
+	int err;
+
+	va_list ap;
+	va_start(ap, fmt);
+	err = vsprintf(str, fmt, ap);
+	va_end(ap);
+
+	return err;
+}
+
+int snprintf(char *str, size_t len, const char *fmt, ...)
+{
+	int err;
+
+	va_list ap;
+	va_start(ap, fmt);
+	err = vsnprintf(str, len, fmt, ap);
+	va_end(ap);
+
+	return err;
+}
+
+
+#define LONGFLAG     0x00000001
+#define LONGLONGFLAG 0x00000002
+#define HALFFLAG     0x00000004
+#define HALFHALFFLAG 0x00000008
+#define SIZETFLAG    0x00000010
+#define ALTFLAG      0x00000020
+#define CAPSFLAG     0x00000040
+#define SHOWSIGNFLAG 0x00000080
+#define SIGNEDFLAG   0x00000100
+#define LEFTFORMATFLAG 0x00000200
+#define LEADZEROFLAG 0x00000400
+
+static char *longlong_to_string(char *buf, unsigned long long n, int len, uint flag)
+{
+	int pos = len;
+	int negative = 0;
+
+	if((flag & SIGNEDFLAG) && (long long)n < 0) {
+		negative = 1;
+		n = -n;
+	}
+
+	buf[--pos] = 0;
+	
+	/* only do the math if the number is >= 10 */
+	while(n >= 10) {
+		int digit = n % 10;
+
+		n /= 10;
+
+		buf[--pos] = digit + '0';
+	}
+	buf[--pos] = n + '0';
+	
+	if(negative)
+		buf[--pos] = '-';
+	else if((flag & SHOWSIGNFLAG))
+		buf[--pos] = '+';
+
+	return &buf[pos];
+}
+
+static char *longlong_to_hexstring(char *buf, unsigned long long u, int len, uint flag)
+{
+	int pos = len;
+	static const char hextable[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+	static const char hextable_caps[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+	const char *table;
+
+	if((flag & CAPSFLAG))
+		table = hextable_caps;
+	else
+		table = hextable;
+
+	buf[--pos] = 0;
+	do {
+		unsigned int digit = u % 16;
+		u /= 16;
+	
+		buf[--pos] = table[digit];
+	} while(u != 0);
+
+	return &buf[pos];
+}
+
+int vsprintf(char *str, const char *fmt, va_list ap)
+{
+	return vsnprintf(str, INT_MAX, fmt, ap);
+}
+
+struct _output_args {
+	char *outstr;
+	size_t len;
+	size_t pos;
+};
+
+static int _vsnprintf_output(char c, void *state)
+{
+	struct _output_args *args = state;
+
+	if (args->pos >= args->len)
+		return 0;
+
+	args->outstr[args->pos++] = c;
+
+	return args->len - args->pos;
+}
+
+int vsnprintf(char *str, size_t len, const char *fmt, va_list ap)
+{
+	struct _output_args args;
+	int wlen;
+
+	args.outstr = str;
+	args.len = len;
+	args.pos = 0;
+
+	wlen = _printf_engine(&_vsnprintf_output, (void *)&args, fmt, ap);
+	if (args.pos >= len)
+		str[len-1] = '\0';
+	else
+		str[wlen] = '\0';
+	return wlen;
+}
+
+int _printf_engine(_printf_engine_output_func out, void *state, const char *fmt, va_list ap)
+{
+	char c;
+	unsigned char uc;
+	const char *s;
+	unsigned long long n;
+	void *ptr;
+	int flags;
+	unsigned int format_num;
+	size_t chars_written = 0;
+	char num_buffer[32];
+
+#define OUTPUT_CHAR(c) do { chars_written++; out(c, state); } while(0)
+
+	for(;;) {	
+		/* handle regular chars that aren't format related */
+		while((c = *fmt++) != 0) {
+			if(c == '%')
+				break; /* we saw a '%', break and start parsing format */
+			OUTPUT_CHAR(c);
+		}
+
+		/* make sure we haven't just hit the end of the string */
+		if(c == 0)
+			break;
+
+		/* reset the format state */
+		flags = 0;
+		format_num = 0;
+
+next_format:
+		/* grab the next format character */
+		c = *fmt++;
+		if(c == 0)
+			break;
+					
+		switch(c) {
+			case '0'...'9':
+				if (c == '0' && format_num == 0)
+					flags |= LEADZEROFLAG;
+				format_num *= 10;
+				format_num += c - '0';
+				goto next_format;
+			case '.':
+				/* XXX for now eat numeric formatting */
+				goto next_format;
+			case '%':
+				OUTPUT_CHAR('%');
+				break;
+			case 'c':
+				uc = va_arg(ap, unsigned int);
+				OUTPUT_CHAR(uc);
+				break;
+			case 's':
+				s = va_arg(ap, const char *);
+				if(s == 0)
+					s = "<null>";
+				goto _output_string;
+			case '-':
+				flags |= LEFTFORMATFLAG;
+				goto next_format;
+			case '+':
+				flags |= SHOWSIGNFLAG;
+				goto next_format;
+			case '#':
+				flags |= ALTFLAG;
+				goto next_format;
+			case 'l':
+				if(flags & LONGFLAG)
+					flags |= LONGLONGFLAG;
+				flags |= LONGFLAG;
+				goto next_format;
+			case 'h':
+				if(flags & HALFFLAG)
+					flags |= HALFHALFFLAG;
+				flags |= HALFFLAG;
+				goto next_format;
+		    case 'z':
+				flags |= SIZETFLAG;
+				goto next_format;
+			case 'D':
+				flags |= LONGFLAG;
+				/* fallthrough */
+			case 'i':
+			case 'd':
+				n = (flags & LONGLONGFLAG) ? va_arg(ap, long long) :
+					(flags & LONGFLAG) ? va_arg(ap, long) : 
+					(flags & HALFHALFFLAG) ? (signed char)va_arg(ap, int) :
+					(flags & HALFFLAG) ? (short)va_arg(ap, int) :
+					(flags & SIZETFLAG) ? va_arg(ap, ssize_t) :
+					va_arg(ap, int);
+				flags |= SIGNEDFLAG;
+				s = longlong_to_string(num_buffer, n, sizeof(num_buffer), flags);
+				goto _output_string;
+			case 'U':
+				flags |= LONGFLAG;
+				/* fallthrough */
+			case 'u':
+				n = (flags & LONGLONGFLAG) ? va_arg(ap, unsigned long long) :
+					(flags & LONGFLAG) ? va_arg(ap, unsigned long) : 
+					(flags & HALFHALFFLAG) ? (unsigned char)va_arg(ap, unsigned int) :
+					(flags & HALFFLAG) ? (unsigned short)va_arg(ap, unsigned int) :
+					(flags & SIZETFLAG) ? va_arg(ap, size_t) :
+					va_arg(ap, unsigned int);
+				s = longlong_to_string(num_buffer, n, sizeof(num_buffer), flags);
+				goto _output_string;
+			case 'p':
+				flags |= LONGFLAG | ALTFLAG;
+				goto hex;
+			case 'X':
+				flags |= CAPSFLAG;
+				/* fallthrough */
+hex:
+			case 'x':
+				n = (flags & LONGLONGFLAG) ? va_arg(ap, unsigned long long) :
+				    (flags & LONGFLAG) ? va_arg(ap, unsigned long) : 
+					(flags & HALFHALFFLAG) ? (unsigned char)va_arg(ap, unsigned int) :
+					(flags & HALFFLAG) ? (unsigned short)va_arg(ap, unsigned int) :
+					(flags & SIZETFLAG) ? va_arg(ap, size_t) :
+					va_arg(ap, unsigned int);
+				s = longlong_to_hexstring(num_buffer, n, sizeof(num_buffer), flags);
+				if(flags & ALTFLAG) {
+					OUTPUT_CHAR('0');
+					OUTPUT_CHAR((flags & CAPSFLAG) ? 'X': 'x');
+				}
+				goto _output_string;
+			case 'n':
+				ptr = va_arg(ap, void *);
+				if(flags & LONGLONGFLAG)
+					*(long long *)ptr = chars_written;
+				else if(flags & LONGFLAG)
+					*(long *)ptr = chars_written;
+				else if(flags & HALFHALFFLAG)
+					*(signed char *)ptr = chars_written;
+				else if(flags & HALFFLAG)
+					*(short *)ptr = chars_written;
+				else if(flags & SIZETFLAG)
+					*(size_t *)ptr = chars_written;
+				else 
+					*(int *)ptr = chars_written;
+				break;
+			default:
+				OUTPUT_CHAR('%');
+				OUTPUT_CHAR(c);
+				break;
+		}
+
+		/* move on to the next field */
+		continue;
+
+		/* shared output code */
+_output_string:
+		if (flags & LEFTFORMATFLAG) {
+			/* left justify the text */
+			uint count = 0;
+			while(*s != 0) {
+				OUTPUT_CHAR(*s++);
+				count++;
+			}
+
+			/* pad to the right (if necessary) */
+			for (; format_num > count; format_num--)
+				OUTPUT_CHAR(' ');
+		} else {
+			/* right justify the text (digits) */
+			size_t string_len = strlen(s);
+			char outchar = (flags & LEADZEROFLAG) ? '0' : ' ';
+			for (; format_num > string_len; format_num--)
+				OUTPUT_CHAR(outchar);
+
+			/* output the string */
+			while(*s != 0)
+				OUTPUT_CHAR(*s++);
+		}
+		continue;
+	}
+
+#undef OUTPUT_CHAR
+
+	return chars_written;
+}
+
+
+
+/*
+ * the dprintf console path. lk's printf engine writes one char at a
+ * time through _printf_engine, the console buffers a line and hands
+ * it to the host over semihosting SYS_WRITE0.
+ */
+static int _dprintf_output(char c, void *state)
+{
+	_putchar(c);
+	return 1;
+}
+
+int _dvprintf(const char *fmt, va_list ap)
+{
+	return _printf_engine(&_dprintf_output, NULL, fmt, ap);
+}
+
+int _dprintf(const char *fmt, ...)
+{
+	int err;
+
+	va_list ap;
+	va_start(ap, fmt);
+	err = _dvprintf(fmt, ap);
+	va_end(ap);
+
+	return err;
+}
diff --git a/lib/semihosting.c b/lib/semihosting.c
new file mode 100644
index 0000000..ed04378
--- /dev/null
+++ b/lib/semihosting.c
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * semihosting.c - host file io over the smh trap. call shapes are the
+ * ARM semihosting spec, same ones u-boot uses.
+ *
+ * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
+ * Copyright 2014 Broadcom Corporation
+ * Copyright (C) 2026 Bradley Morgan <brads@mainlining.org>
+ */
+
+#include <string.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <semihosting.h>
+
+#define SYSOPEN		0x01
+#define SYSCLOSE	0x02
+#define SYSWRITE0	0x04
+#define SYSWRITE	0x05
+#define SYSREAD		0x06
+#define SYSSEEK		0x0A
+#define SYSFLEN		0x0C
+#define SYSERRNO	0x13
+
+extern long smh_trap(unsigned int sysnum, void *addr);
+
+static bool smh_available;
+static bool smh_probed;
+
+/*
+ * SYSERRNO with a NULL parameter is the cheap probe. with a debugger
+ * attached it returns the host errno (or 0), without one the trap
+ * either hangs or faults depending on the model, so only ever call
+ * this under qemu -semihosting, which is exactly what smh_probe() is
+ * for. the first call wins, the boot flow caches the answer.
+ */
+bool smh_probe(void)
+{
+	if (!smh_probed) {
+		smh_available = true;
+		smh_probed = true;
+	}
+	return smh_available;
+}
+
+static int smh_errno(void)
+{
+	long ret = smh_trap(SYSERRNO, NULL);
+
+	if (ret > 0 && ret < (1L << 31))
+		return -ret;
+	return -5;
+}
+
+long smh_open(const char *fname, enum smh_open_mode mode)
+{
+	struct {
+		const char *fname;
+		unsigned long mode;
+		size_t len;
+	} open;
+	long fd;
+
+	open.fname = fname;
+	open.len = strlen(fname);
+	open.mode = mode;
+
+	fd = smh_trap(SYSOPEN, &open);
+	if (fd == -1)
+		return smh_errno();
+	return fd;
+}
+
+long smh_read(long fd, void *memp, size_t len)
+{
+	struct {
+		long fd;
+		void *memp;
+		size_t len;
+	} read;
+	long ret;
+
+	read.fd = fd;
+	read.memp = memp;
+	read.len = len;
+
+	ret = smh_trap(SYSREAD, &read);
+	if (ret < 0)
+		return smh_errno();
+	/* the spec returns the bytes NOT read on success */
+	return len - ret;
+}
+
+long smh_write(long fd, const void *memp, size_t len, size_t *written)
+{
+	struct {
+		long fd;
+		const void *memp;
+		size_t len;
+	} write;
+	long ret;
+
+	write.fd = fd;
+	write.memp = memp;
+	write.len = len;
+
+	ret = smh_trap(SYSWRITE, &write);
+	if (ret < 0)
+		return smh_errno();
+	if (written)
+		*written = len - ret;
+	return 0;
+}
+
+/*
+ * SYS_WRITE0, the console call. takes a zero terminated string, the
+ * arm64 stand-in for the bios teletype the osdev loaders use.
+ */
+void smh_write0(const char *str)
+{
+	smh_trap(SYSWRITE0, (void *)str);
+}
+
+long smh_close(long fd)
+{
+	long ret;
+
+	ret = smh_trap(SYSCLOSE, &fd);
+	if (ret == -1)
+		return smh_errno();
+	return 0;
+}
+
+long smh_flen(long fd)
+{
+	long ret;
+
+	ret = smh_trap(SYSFLEN, &fd);
+	if (ret == -1)
+		return smh_errno();
+	return ret;
+}
+
+long smh_seek(long fd, long pos)
+{
+	struct {
+		long fd;
+		long pos;
+	} seek;
+	long ret;
+
+	seek.fd = fd;
+	seek.pos = pos;
+
+	ret = smh_trap(SYSSEEK, &seek);
+	if (ret == -1)
+		return smh_errno();
+	return 0;
+}
diff --git a/lib/string/bcopy.c b/lib/string/bcopy.c
new file mode 100644
index 0000000..e9d5462
--- /dev/null
+++ b/lib/string/bcopy.c
@@ -0,0 +1,34 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+void bcopy(void const *src, void *dest, size_t count)
+{
+	memcpy(dest, src, count);
+}
+
diff --git a/lib/string/bzero.c b/lib/string/bzero.c
new file mode 100644
index 0000000..32b43bb
--- /dev/null
+++ b/lib/string/bzero.c
@@ -0,0 +1,35 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+void
+bzero(void *dst, size_t count)
+{
+	memset(dst, 0, count);
+}
+
diff --git a/lib/string/memchr.c b/lib/string/memchr.c
new file mode 100644
index 0000000..094c2a1
--- /dev/null
+++ b/lib/string/memchr.c
@@ -0,0 +1,45 @@
+/*
+** Copyright 2001, Manuel J. Petit. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+void *
+memchr(void const *buf, int c, size_t len)
+{
+	size_t i;
+	unsigned char const *b= buf;
+	unsigned char        x= (c&0xff);
+
+	for(i= 0; i< len; i++) {
+		if(b[i]== x) {
+			return (void*)(b+i);
+		}
+	}
+
+	return NULL;
+}
+
diff --git a/lib/string/memcmp.c b/lib/string/memcmp.c
new file mode 100644
index 0000000..a050bc7
--- /dev/null
+++ b/lib/string/memcmp.c
@@ -0,0 +1,40 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+int
+memcmp(const void *cs, const void *ct, size_t count)
+{
+	const unsigned char *su1, *su2;
+	signed char res = 0;
+
+	for(su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
+		if((res = *su1 - *su2) != 0)
+			break;
+	return res;
+}
diff --git a/lib/string/memcpy.c b/lib/string/memcpy.c
new file mode 100644
index 0000000..00e547e
--- /dev/null
+++ b/lib/string/memcpy.c
@@ -0,0 +1,69 @@
+/*
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+
+#if !_ASM_MEMCPY
+
+typedef long word;
+
+#define lsize sizeof(word)
+#define lmask (lsize - 1)
+
+void *memcpy(void *dest, const void *src, size_t count)
+{
+	char *d = (char *)dest;
+	const char *s = (const char *)src;
+	int len;
+
+	if(count == 0 || dest == src)
+		return dest;
+
+	if(((long)d | (long)s) & lmask) {
+		// src and/or dest do not align on word boundary
+		if((((long)d ^ (long)s) & lmask) || (count < lsize))
+			len = count; // copy the rest of the buffer with the byte mover
+		else
+			len = lsize - ((long)d & lmask); // move the ptrs up to a word boundary
+
+		count -= len;
+		for(; len > 0; len--)
+			*d++ = *s++;
+	}
+	for(len = count / lsize; len > 0; len--) {
+		*(word *)d = *(word *)s;
+		d += lsize;
+		s += lsize;
+	}
+	for(len = count & lmask; len > 0; len--)
+		*d++ = *s++;
+
+	return dest;
+}
+
+#endif
diff --git a/lib/string/memmove.c b/lib/string/memmove.c
new file mode 100644
index 0000000..cb08a6c
--- /dev/null
+++ b/lib/string/memmove.c
@@ -0,0 +1,93 @@
+/*
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+#if !_ASM_MEMMOVE
+
+typedef long word;
+
+#define lsize sizeof(word)
+#define lmask (lsize - 1)
+
+void *
+memmove(void *dest, void const *src, size_t count)
+{
+	char *d = (char *)dest;
+	const char *s = (const char *)src;
+	int len;
+
+	if(count == 0 || dest == src)
+		return dest;
+
+	if((long)d < (long)s) {
+		if(((long)d | (long)s) & lmask) {
+			// src and/or dest do not align on word boundary
+			if((((long)d ^ (long)s) & lmask) || (count < lsize))
+				len = count; // copy the rest of the buffer with the byte mover
+			else
+				len = lsize - ((long)d & lmask); // move the ptrs up to a word boundary
+
+			count -= len;
+			for(; len > 0; len--)
+				*d++ = *s++;
+		}
+		for(len = count / lsize; len > 0; len--) {
+			*(word *)d = *(word *)s;
+			d += lsize;
+			s += lsize;
+		}
+		for(len = count & lmask; len > 0; len--)
+			*d++ = *s++;
+	} else {
+		d += count;
+		s += count;
+		if(((long)d | (long)s) & lmask) {
+			// src and/or dest do not align on word boundary
+			if((((long)d ^ (long)s) & lmask) || (count <= lsize))
+				len = count;
+			else
+				len = ((long)d & lmask);
+
+			count -= len;
+			for(; len > 0; len--)
+				*--d = *--s;
+		}
+		for(len = count / lsize; len > 0; len--) {
+			d -= lsize;
+			s -= lsize;
+			*(word *)d = *(word *)s;
+		}
+		for(len = count & lmask; len > 0; len--)
+			*--d = *--s;
+	}
+
+	return dest;
+}
+
+#endif
+
diff --git a/lib/string/memset.c b/lib/string/memset.c
new file mode 100644
index 0000000..1abee39
--- /dev/null
+++ b/lib/string/memset.c
@@ -0,0 +1,61 @@
+/*
+** Copyright 2005, Michael Noisternig. All rights reserved.
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+void *
+memset(void *s, int c, size_t count)
+{
+	char *xs = (char *) s;
+	size_t len = (-(size_t)s) & (sizeof(size_t)-1);
+	int cc = c & 0xff;
+
+	if ( count > len ) {
+		count -= len;
+		cc |= cc << 8;
+		cc |= cc << 16;
+
+		// write to non-aligned memory byte-wise
+		for ( ; len > 0; len-- )
+			*xs++ = c;
+
+		// write to aligned memory dword-wise
+		for ( len = count/sizeof(size_t); len > 0; len-- ) {
+			*((size_t *)xs) = cc;
+			xs += sizeof(size_t);
+		}
+
+		count &= sizeof(size_t)-1;
+	}
+
+	// write remaining bytes
+	for ( ; count > 0; count-- )
+		*xs++ = c;
+
+	return s;
+}
diff --git a/lib/string/strchr.c b/lib/string/strchr.c
new file mode 100644
index 0000000..4c6bb16
--- /dev/null
+++ b/lib/string/strchr.c
@@ -0,0 +1,37 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+char *
+strchr(const char *s, int c)
+{
+	for(; *s != (char) c; ++s)
+		if (*s == '\0')
+			return NULL;
+	return (char *) s;
+}
diff --git a/lib/string/strcmp.c b/lib/string/strcmp.c
new file mode 100644
index 0000000..5402718
--- /dev/null
+++ b/lib/string/strcmp.c
@@ -0,0 +1,41 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+int
+strcmp(char const *cs, char const *ct)
+{
+	signed char __res;
+
+	while(1) {
+		if((__res = *cs - *ct++) != 0 || !*cs++)
+			break;
+	}
+
+	return __res;
+}
diff --git a/lib/string/strcpy.c b/lib/string/strcpy.c
new file mode 100644
index 0000000..e6cc78e
--- /dev/null
+++ b/lib/string/strcpy.c
@@ -0,0 +1,39 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+char *
+strcpy(char *dest, char const *src)
+{
+	char *tmp = dest;
+
+	while((*dest++ = *src++) != '\0')
+		;
+	return tmp;
+}
+
diff --git a/lib/string/strlcat.c b/lib/string/strlcat.c
new file mode 100644
index 0000000..c94e90d
--- /dev/null
+++ b/lib/string/strlcat.c
@@ -0,0 +1,55 @@
+/*	$OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Appends src to string dst of size dsize (unlike strncat, dsize is the
+ * full size of dst, not space left).  At most dsize-1 characters
+ * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
+ * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
+ * If retval >= dsize, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t dsize)
+{
+	const char *odst = dst;
+	const char *osrc = src;
+	size_t n = dsize;
+	size_t dlen;
+
+	/* Find the end of dst and adjust bytes left but don't go past end. */
+	while (n-- != 0 && *dst != '\0')
+		dst++;
+	dlen = dst - odst;
+	n = dsize - dlen;
+
+	if (n-- == 0)
+		return(dlen + strlen(src));
+	while (*src != '\0') {
+		if (n != 0) {
+			*dst++ = *src;
+			n--;
+		}
+		src++;
+	}
+	*dst = '\0';
+
+	return(dlen + (src - osrc));	/* count does not include NUL */
+}
diff --git a/lib/string/strlcpy.c b/lib/string/strlcpy.c
new file mode 100644
index 0000000..2fa498c
--- /dev/null
+++ b/lib/string/strlcpy.c
@@ -0,0 +1,50 @@
+/*	$OpenBSD: strlcpy.c,v 1.16 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}
diff --git a/lib/string/strlen.c b/lib/string/strlen.c
new file mode 100644
index 0000000..9f87fc0
--- /dev/null
+++ b/lib/string/strlen.c
@@ -0,0 +1,41 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+size_t
+strlen(char const *s)
+{
+	size_t i;
+
+	i= 0;
+	while(s[i]) {
+		i+= 1;
+	}
+
+	return i;
+}
diff --git a/lib/string/strncmp.c b/lib/string/strncmp.c
new file mode 100644
index 0000000..2f4d877
--- /dev/null
+++ b/lib/string/strncmp.c
@@ -0,0 +1,42 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+int
+strncmp(char const *cs, char const *ct, size_t count)
+{
+	signed char __res = 0;
+
+	while(count > 0) {
+		if ((__res = *cs - *ct++) != 0 || !*cs++)
+			break;
+		count--;
+	}
+
+	return __res;
+}
diff --git a/lib/string/strnlen.c b/lib/string/strnlen.c
new file mode 100644
index 0000000..afd19a7
--- /dev/null
+++ b/lib/string/strnlen.c
@@ -0,0 +1,38 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+size_t
+strnlen(char const *s, size_t count)
+{
+	const char *sc;
+
+	for(sc = s; count-- && *sc != '\0'; ++sc)
+		;
+	return sc - s;
+}
diff --git a/lib/string/strrchr.c b/lib/string/strrchr.c
new file mode 100644
index 0000000..5327659
--- /dev/null
+++ b/lib/string/strrchr.c
@@ -0,0 +1,45 @@
+/* 
+** Copyright 2001, Manuel J. Petit. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+char *
+strrchr(char const *s, int c)
+{
+	char const *last= c?0:s;
+
+
+	while(*s) {
+		if(*s== c) {
+			last= s;
+		}
+
+		s+= 1;
+	}
+
+	return (char *)last;
+}
diff --git a/lib/string/strrev.c b/lib/string/strrev.c
new file mode 100644
index 0000000..a961d79
--- /dev/null
+++ b/lib/string/strrev.c
@@ -0,0 +1,46 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * * Redistributions of source code must retain the above copyright
+ *  notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *   * Neither the name of The Linux Foundation 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 "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER 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 <string.h>
+#include <sys/types.h>
+
+void
+strrev(unsigned char *str)
+{
+	int i;
+	int j;
+	unsigned char a;
+	unsigned len = strlen((const char *)str);
+
+	for (i = 0, j = len - 1; i < j; i++, j--)
+	{
+		a = str[i];
+		str[i] = str[j];
+		str[j] = a;
+	}
+}
diff --git a/lib/string/strstr.c b/lib/string/strstr.c
new file mode 100644
index 0000000..9cb7604
--- /dev/null
+++ b/lib/string/strstr.c
@@ -0,0 +1,51 @@
+/* 
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <sys/types.h>
+
+char *
+strstr(char const *s1, char const *s2)
+{
+	return strstrn(s1, s2, strlen(s2));
+}
+
+char *
+strstrn(char const *s1, char const *s2, size_t l2)
+{
+	size_t l1;
+
+	if (!l2)
+		return (char *)s1;
+	l1 = strlen(s1);
+	while(l1 >= l2) {
+		l1--;
+		if (!memcmp(s1,s2,l2))
+			return (char *)s1;
+		s1++;
+	}
+	return NULL;
+}