Setup project skeleton

12 files changed, 671 insertions, 0 deletions

diff --git a/src/libc/newlib/CMakeLists.txt b/src/libc/newlib/CMakeLists.txt
new file mode 100644
index 0000000..aedf961
--- /dev/null
+++ b/src/libc/newlib/CMakeLists.txt
@@ -0,0 +1,18 @@
+# wnix, a Unix-like operating system for WebAssembly applications.
+# Copyright (C) 2025  Xavier Del Campo Romero
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+add_subdirectory(src)
+target_include_directories(c PRIVATE private_include)
diff --git a/src/libc/newlib/private_include/sys/_tz_structs.h b/src/libc/newlib/private_include/sys/_tz_structs.h
new file mode 100644
index 0000000..f20aacb
--- /dev/null
+++ b/src/libc/newlib/private_include/sys/_tz_structs.h
@@ -0,0 +1,30 @@
+#ifndef _SYS__TZ_STRUCTS_H_
+#define _SYS__TZ_STRUCTS_H_
+
+#include <time.h>
+
+typedef struct __tzrule_struct
+{
+  char ch;
+  int m; /* Month of year if ch=M */
+  int n; /* Week of month if ch=M */
+  int d; /* Day of week if ch=M, day of year if ch=J or ch=D */
+  int s; /* Time of day in seconds */
+  time_t change;
+  long offset; /* Match type of _timezone. */
+} __tzrule_type;
+
+typedef struct __tzinfo_struct
+{
+  int __tznorth;
+  int __tzyear;
+  __tzrule_type __tzrule[2];
+} __tzinfo_type;
+
+__tzinfo_type *__gettzinfo (void);
+
+extern char *_tzname[2];
+extern int _daylight;
+extern long _timezone;
+
+#endif /* _SYS__TZ_STRUCTS_H_ */
diff --git a/src/libc/newlib/src/CMakeLists.txt b/src/libc/newlib/src/CMakeLists.txt
new file mode 100644
index 0000000..f2f8ba4
--- /dev/null
+++ b/src/libc/newlib/src/CMakeLists.txt
@@ -0,0 +1,18 @@
+# wnix, a Unix-like operating system for WebAssembly applications.
+# Copyright (C) 2025  Xavier Del Campo Romero
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+add_subdirectory(stdlib)
+add_subdirectory(time)
diff --git a/src/libc/newlib/src/stdlib/CMakeLists.txt b/src/libc/newlib/src/stdlib/CMakeLists.txt
new file mode 100644
index 0000000..ab499b9
--- /dev/null
+++ b/src/libc/newlib/src/stdlib/CMakeLists.txt
@@ -0,0 +1,19 @@
+# wnix, a Unix-like operating system for WebAssembly applications.
+# Copyright (C) 2025  Xavier Del Campo Romero
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+target_sources(c PRIVATE
+    div.c
+)
diff --git a/src/libc/newlib/src/stdlib/div.c b/src/libc/newlib/src/stdlib/div.c
new file mode 100644
index 0000000..2a19cae
--- /dev/null
+++ b/src/libc/newlib/src/stdlib/div.c
@@ -0,0 +1,121 @@
+/*
+FUNCTION
+<<div>>---divide two integers
+
+INDEX
+	div
+
+SYNOPSIS
+	#include <stdlib.h>
+	div_t div(int <[n]>, int <[d]>);
+
+DESCRIPTION
+Divide
+@tex
+$n/d$,
+@end tex
+@ifnottex
+<[n]>/<[d]>,
+@end ifnottex
+returning quotient and remainder as two integers in a structure <<div_t>>.
+
+RETURNS
+The result is represented with the structure
+
+. typedef struct
+. {
+.  int quot;
+.  int rem;
+. } div_t;
+
+where the <<quot>> field represents the quotient, and <<rem>> the
+remainder.  For nonzero <[d]>, if `<<<[r]> = div(<[n]>,<[d]>);>>' then
+<[n]> equals `<<<[r]>.rem + <[d]>*<[r]>.quot>>'.
+
+To divide <<long>> rather than <<int>> values, use the similar
+function <<ldiv>>.
+
+PORTABILITY
+<<div>> is ANSI.
+
+No supporting OS subroutines are required.
+*/
+
+/*
+ * Copyright (c) 1990 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.
+ */
+
+#include <stdlib.h>		/* div_t */
+
+div_t
+div (int num,
+	int denom)
+{
+	div_t r;
+
+	r.quot = num / denom;
+	r.rem = num % denom;
+	/*
+	 * The ANSI standard says that |r.quot| <= |n/d|, where
+	 * n/d is to be computed in infinite precision.  In other
+	 * words, we should always truncate the quotient towards
+	 * 0, never -infinity or +infinity.
+	 *
+	 * Machine division and remainer may work either way when
+	 * one or both of n or d is negative.  If only one is
+	 * negative and r.quot has been truncated towards -inf,
+	 * r.rem will have the same sign as denom and the opposite
+	 * sign of num; if both are negative and r.quot has been
+	 * truncated towards -inf, r.rem will be positive (will
+	 * have the opposite sign of num).  These are considered
+	 * `wrong'.
+	 *
+	 * If both are num and denom are positive, r will always
+	 * be positive.
+	 *
+	 * This all boils down to:
+	 *	if num >= 0, but r.rem < 0, we got the wrong answer.
+	 * In that case, to get the right answer, add 1 to r.quot and
+	 * subtract denom from r.rem.
+	 *      if num < 0, but r.rem > 0, we also have the wrong answer.
+	 * In this case, to get the right answer, subtract 1 from r.quot and
+	 * add denom to r.rem.
+	 */
+	if (num >= 0 && r.rem < 0) {
+		++r.quot;
+		r.rem -= denom;
+	}
+	else if (num < 0 && r.rem > 0) {
+		--r.quot;
+		r.rem += denom;
+	}
+	return (r);
+}
diff --git a/src/libc/newlib/src/time/CMakeLists.txt b/src/libc/newlib/src/time/CMakeLists.txt
new file mode 100644
index 0000000..ea7167f
--- /dev/null
+++ b/src/libc/newlib/src/time/CMakeLists.txt
@@ -0,0 +1,25 @@
+# wnix, a Unix-like operating system for WebAssembly applications.
+# Copyright (C) 2025  Xavier Del Campo Romero
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+target_sources(c PRIVATE
+    gettzinfo.c
+    month_lengths.c
+    mktime.c
+    tzvars.c
+    tzcalc_limits.c
+)
+
+target_compile_definitions(c PRIVATE __SINGLE_THREAD__)
diff --git a/src/libc/newlib/src/time/gettzinfo.c b/src/libc/newlib/src/time/gettzinfo.c
new file mode 100644
index 0000000..c28e72f
--- /dev/null
+++ b/src/libc/newlib/src/time/gettzinfo.c
@@ -0,0 +1,15 @@
+#include <sys/types.h>
+#include "local.h"
+
+/* Shared timezone information for libc/time functions.  */
+static __tzinfo_type tzinfo = {1, 0,
+    { {'J', 0, 0, 0, 0, (time_t)0, 0L },
+      {'J', 0, 0, 0, 0, (time_t)0, 0L } 
+    } 
+};
+
+__tzinfo_type *
+__gettzinfo (void)
+{
+  return &tzinfo;
+}
diff --git a/src/libc/newlib/src/time/local.h b/src/libc/newlib/src/time/local.h
new file mode 100644
index 0000000..41940c0
--- /dev/null
+++ b/src/libc/newlib/src/time/local.h
@@ -0,0 +1,38 @@
+/* local header used by libc/time routines */
+#include <time.h>
+#include <sys/_tz_structs.h>
+
+#define SECSPERMIN	60L
+#define MINSPERHOUR	60L
+#define HOURSPERDAY	24L
+#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
+#define SECSPERDAY	(SECSPERHOUR * HOURSPERDAY)
+#define DAYSPERWEEK	7
+#define MONSPERYEAR	12
+
+#define YEAR_BASE	1900
+#define EPOCH_YEAR      1970
+#define EPOCH_WDAY      4
+#define EPOCH_YEARS_SINCE_LEAP 2
+#define EPOCH_YEARS_SINCE_CENTURY 70
+#define EPOCH_YEARS_SINCE_LEAP_CENTURY 370
+
+#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
+
+int         __tzcalc_limits (int __year);
+
+extern const int __month_lengths[2][MONSPERYEAR];
+
+void _tzset_unlocked (void);
+
+/* locks for multi-threading */
+#ifdef __SINGLE_THREAD__
+#define TZ_LOCK
+#define TZ_UNLOCK
+#else
+#define TZ_LOCK __tz_lock()
+#define TZ_UNLOCK __tz_unlock()
+#endif
+
+void __tz_lock (void);
+void __tz_unlock (void);
diff --git a/src/libc/newlib/src/time/mktime.c b/src/libc/newlib/src/time/mktime.c
new file mode 100644
index 0000000..4ca1493
--- /dev/null
+++ b/src/libc/newlib/src/time/mktime.c
@@ -0,0 +1,288 @@
+/*
+ * mktime.c
+ * Original Author:	G. Haley
+ *
+ * Converts the broken-down time, expressed as local time, in the structure
+ * pointed to by tim_p into a calendar time value. The original values of the
+ * tm_wday and tm_yday fields of the structure are ignored, and the original
+ * values of the other fields have no restrictions. On successful completion
+ * the fields of the structure are set to represent the specified calendar
+ * time. Returns the specified calendar time. If the calendar time can not be
+ * represented, returns the value (time_t) -1.
+ *
+ * Modifications:	Fixed tm_isdst usage - 27 August 2008 Craig Howland.
+ */
+
+/*
+FUNCTION
+<<mktime>>---convert time to arithmetic representation
+
+INDEX
+	mktime
+
+SYNOPSIS
+	#include <time.h>
+	time_t mktime(struct tm *<[timp]>);
+
+DESCRIPTION
+<<mktime>> assumes the time at <[timp]> is a local time, and converts
+its representation from the traditional representation defined by
+<<struct tm>> into a representation suitable for arithmetic.
+
+<<localtime>> is the inverse of <<mktime>>.
+
+RETURNS
+If the contents of the structure at <[timp]> do not form a valid
+calendar time representation, the result is <<-1>>.  Otherwise, the
+result is the time, converted to a <<time_t>> value.
+
+PORTABILITY
+ANSI C requires <<mktime>>.
+
+<<mktime>> requires no supporting OS subroutines.
+*/
+
+#include "local.h"
+#include <stdlib.h>
+#include <sys/_tz_structs.h>
+#include <time.h>
+
+#define TZ_LOCK
+#define TZ_UNLOCK
+#define _tzset_unlocked()
+#define YEAR_BASE	1900
+
+#define _SEC_IN_MINUTE 60L
+#define _SEC_IN_HOUR 3600L
+#define _SEC_IN_DAY 86400L
+
+static const int DAYS_IN_MONTH[12] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+#define _DAYS_IN_MONTH(x) ((x == 1) ? days_in_feb : DAYS_IN_MONTH[x])
+
+static const int _DAYS_BEFORE_MONTH[12] =
+{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
+
+#define _ISLEAP(y) (((y) % 4) == 0 && (((y) % 100) != 0 || (((y)+1900) % 400) == 0))
+#define _DAYS_IN_YEAR(year) (_ISLEAP(year) ? 366 : 365)
+
+static void
+validate_structure (struct tm *tim_p)
+{
+  div_t res;
+  int days_in_feb = 28;
+
+  /* calculate time & date to account for out of range values */
+  if (tim_p->tm_sec < 0 || tim_p->tm_sec > 59)
+    {
+      res = div (tim_p->tm_sec, 60);
+      tim_p->tm_min += res.quot;
+      if ((tim_p->tm_sec = res.rem) < 0)
+	{
+	  tim_p->tm_sec += 60;
+	  --tim_p->tm_min;
+	}
+    }
+
+  if (tim_p->tm_min < 0 || tim_p->tm_min > 59)
+    {
+      res = div (tim_p->tm_min, 60);
+      tim_p->tm_hour += res.quot;
+      if ((tim_p->tm_min = res.rem) < 0)
+	{
+	  tim_p->tm_min += 60;
+	  --tim_p->tm_hour;
+        }
+    }
+
+  if (tim_p->tm_hour < 0 || tim_p->tm_hour > 23)
+    {
+      res = div (tim_p->tm_hour, 24);
+      tim_p->tm_mday += res.quot;
+      if ((tim_p->tm_hour = res.rem) < 0)
+	{
+	  tim_p->tm_hour += 24;
+	  --tim_p->tm_mday;
+        }
+    }
+
+  if (tim_p->tm_mon < 0 || tim_p->tm_mon > 11)
+    {
+      res = div (tim_p->tm_mon, 12);
+      tim_p->tm_year += res.quot;
+      if ((tim_p->tm_mon = res.rem) < 0)
+        {
+	  tim_p->tm_mon += 12;
+	  --tim_p->tm_year;
+        }
+    }
+
+  if (_DAYS_IN_YEAR (tim_p->tm_year) == 366)
+    days_in_feb = 29;
+
+  if (tim_p->tm_mday <= 0)
+    {
+      while (tim_p->tm_mday <= 0)
+	{
+	  if (--tim_p->tm_mon == -1)
+	    {
+	      tim_p->tm_year--;
+	      tim_p->tm_mon = 11;
+	      days_in_feb =
+		((_DAYS_IN_YEAR (tim_p->tm_year) == 366) ?
+		 29 : 28);
+	    }
+	  tim_p->tm_mday += _DAYS_IN_MONTH (tim_p->tm_mon);
+	}
+    }
+  else
+    {
+      while (tim_p->tm_mday > _DAYS_IN_MONTH (tim_p->tm_mon))
+	{
+	  tim_p->tm_mday -= _DAYS_IN_MONTH (tim_p->tm_mon);
+	  if (++tim_p->tm_mon == 12)
+	    {
+	      tim_p->tm_year++;
+	      tim_p->tm_mon = 0;
+	      days_in_feb =
+		((_DAYS_IN_YEAR (tim_p->tm_year) == 366) ?
+		 29 : 28);
+	    }
+	}
+    }
+}
+
+time_t
+mktime (struct tm *tim_p)
+{
+  time_t tim = 0;
+  long days = 0;
+  int year, isdst=0;
+  __tzinfo_type *tz = __gettzinfo ();
+
+  /* validate structure */
+  validate_structure (tim_p);
+
+  /* compute hours, minutes, seconds */
+  tim += tim_p->tm_sec + (tim_p->tm_min * _SEC_IN_MINUTE) +
+    (tim_p->tm_hour * _SEC_IN_HOUR);
+
+  /* compute days in year */
+  days += tim_p->tm_mday - 1;
+  days += _DAYS_BEFORE_MONTH[tim_p->tm_mon];
+  if (tim_p->tm_mon > 1 && _DAYS_IN_YEAR (tim_p->tm_year) == 366)
+    days++;
+
+  /* compute day of the year */
+  tim_p->tm_yday = days;
+
+  if (tim_p->tm_year > 10000 || tim_p->tm_year < -10000)
+      return (time_t) -1;
+
+  /* compute days in other years */
+  if ((year = tim_p->tm_year) > 70)
+    {
+      for (year = 70; year < tim_p->tm_year; year++)
+	days += _DAYS_IN_YEAR (year);
+    }
+  else if (year < 70)
+    {
+      for (year = 69; year > tim_p->tm_year; year--)
+	days -= _DAYS_IN_YEAR (year);
+      days -= _DAYS_IN_YEAR (year);
+    }
+
+  /* compute total seconds */
+  tim += (time_t)days * _SEC_IN_DAY;
+
+  TZ_LOCK;
+
+  _tzset_unlocked ();
+
+  if (_daylight)
+    {
+      int tm_isdst;
+      int y = tim_p->tm_year + YEAR_BASE;
+      /* Convert user positive into 1 */
+      tm_isdst = tim_p->tm_isdst > 0  ?  1 : tim_p->tm_isdst;
+      isdst = tm_isdst;
+
+      if (y == tz->__tzyear || __tzcalc_limits (y))
+	{
+	  /* calculate start of dst in dst local time and
+	     start of std in both std local time and dst local time */
+          time_t startdst_dst = tz->__tzrule[0].change
+	    - (time_t) tz->__tzrule[1].offset;
+	  time_t startstd_dst = tz->__tzrule[1].change
+	    - (time_t) tz->__tzrule[1].offset;
+	  time_t startstd_std = tz->__tzrule[1].change
+	    - (time_t) tz->__tzrule[0].offset;
+	  /* if the time is in the overlap between dst and std local times */
+	  if (tim >= startstd_std && tim < startstd_dst)
+	    ; /* we let user decide or leave as -1 */
+          else
+	    {
+	      isdst = (tz->__tznorth
+		       ? (tim >= startdst_dst && tim < startstd_std)
+		       : (tim >= startdst_dst || tim < startstd_std));
+ 	      /* if user committed and was wrong, perform correction, but not
+ 	       * if the user has given a negative value (which
+ 	       * asks mktime() to determine if DST is in effect or not) */
+ 	      if (tm_isdst >= 0  &&  (isdst ^ tm_isdst) == 1)
+		{
+		  /* we either subtract or add the difference between
+		     time zone offsets, depending on which way the user got it
+		     wrong. The diff is typically one hour, or 3600 seconds,
+		     and should fit in a 16-bit int, even though offset
+		     is a long to accomodate 12 hours. */
+		  int diff = (int) (tz->__tzrule[0].offset
+				    - tz->__tzrule[1].offset);
+		  if (!isdst)
+		    diff = -diff;
+		  tim_p->tm_sec += diff;
+		  tim += diff;  /* we also need to correct our current time calculation */
+		  int mday = tim_p->tm_mday;
+		  validate_structure (tim_p);
+		  mday = tim_p->tm_mday - mday;
+		  /* roll over occurred */
+		  if (mday) {
+		    /* compensate for month roll overs */
+		    if (mday > 1)
+			  mday = -1;
+		    else if (mday < -1)
+			  mday = 1;
+		    /* update days for wday calculation */
+		    days += mday;
+		    /* handle yday */
+		    if ((tim_p->tm_yday += mday) < 0) {
+			  --year;
+			  tim_p->tm_yday = _DAYS_IN_YEAR(year) - 1;
+		    } else {
+			  mday = _DAYS_IN_YEAR(year);
+			  if (tim_p->tm_yday > (mday - 1))
+				tim_p->tm_yday -= mday;
+		    }
+		  }
+		}
+	    }
+	}
+    }
+
+  /* add appropriate offset to put time in gmt format */
+  if (isdst == 1)
+    tim += (time_t) tz->__tzrule[1].offset;
+  else /* otherwise assume std time */
+    tim += (time_t) tz->__tzrule[0].offset;
+
+  TZ_UNLOCK;
+
+  /* reset isdst flag to what we have calculated */
+  tim_p->tm_isdst = isdst;
+
+  /* compute day of the week */
+  if ((tim_p->tm_wday = (days + 4) % 7) < 0)
+    tim_p->tm_wday += 7;
+
+  return tim;
+}
diff --git a/src/libc/newlib/src/time/month_lengths.c b/src/libc/newlib/src/time/month_lengths.c
new file mode 100644
index 0000000..03fac2f
--- /dev/null
+++ b/src/libc/newlib/src/time/month_lengths.c
@@ -0,0 +1,14 @@
+/*
+ * month_lengths.c
+ *
+ * Array __month_lengths[] is (indirectly) needed by tzset(), mktime(),
+ * gmtime() and localtime(). To break any dependencies, this array is moved to
+ * separate source file.
+ */
+
+#include "local.h"
+
+const int __month_lengths[2][MONSPERYEAR] = {
+  {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
+  {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
+} ;
diff --git a/src/libc/newlib/src/time/tzcalc_limits.c b/src/libc/newlib/src/time/tzcalc_limits.c
new file mode 100644
index 0000000..00044a5
--- /dev/null
+++ b/src/libc/newlib/src/time/tzcalc_limits.c
@@ -0,0 +1,76 @@
+/*
+ * tzcalc_limits.c
+ * Original Author: Adapted from tzcode maintained by Arthur David Olson.
+ * Modifications:
+ * - Changed to mktm_r and added __tzcalc_limits - 04/10/02, Jeff Johnston
+ * - Fixed bug in mday computations - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru>
+ * - Fixed bug in __tzcalc_limits - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru>
+ * - Moved __tzcalc_limits() to separate file - 05/09/14, Freddie Chopin <freddie_chopin@op.pl>
+ */
+
+#include "local.h"
+
+int
+__tzcalc_limits (int year)
+{
+  int days, year_days, years;
+  int i, j;
+  __tzinfo_type *const tz = __gettzinfo ();
+
+  if (year < EPOCH_YEAR)
+    return 0;
+
+  tz->__tzyear = year;
+
+  years = (year - EPOCH_YEAR);
+
+  year_days = years * 365 +
+    (years - 1 + EPOCH_YEARS_SINCE_LEAP) / 4 -
+    (years - 1 + EPOCH_YEARS_SINCE_CENTURY) / 100 +
+    (years - 1 + EPOCH_YEARS_SINCE_LEAP_CENTURY) / 400;
+
+  for (i = 0; i < 2; ++i)
+    {
+      if (tz->__tzrule[i].ch == 'J')
+	{
+	  /* The Julian day n (1 <= n <= 365). */
+	  days = year_days + tz->__tzrule[i].d +
+	    (isleap(year) && tz->__tzrule[i].d >= 60);
+	  /* Convert to yday */
+	  --days;
+	}
+      else if (tz->__tzrule[i].ch == 'D')
+	days = year_days + tz->__tzrule[i].d;
+      else
+	{
+	  const int yleap = isleap(year);
+	  int m_day, m_wday, wday_diff;
+	  const int *const ip = __month_lengths[yleap];
+
+	  days = year_days;
+
+	  for (j = 1; j < tz->__tzrule[i].m; ++j)
+	    days += ip[j-1];
+
+	  m_wday = (EPOCH_WDAY + days) % DAYSPERWEEK;
+
+	  wday_diff = tz->__tzrule[i].d - m_wday;
+	  if (wday_diff < 0)
+	    wday_diff += DAYSPERWEEK;
+	  m_day = (tz->__tzrule[i].n - 1) * DAYSPERWEEK + wday_diff;
+
+	  while (m_day >= ip[j-1])
+	    m_day -= DAYSPERWEEK;
+
+	  days += m_day;
+	}
+
+      /* store the change-over time in GMT form by adding offset */
+      tz->__tzrule[i].change = (time_t) days * SECSPERDAY +
+      tz->__tzrule[i].s + tz->__tzrule[i].offset;
+    }
+
+  tz->__tznorth = (tz->__tzrule[0].change < tz->__tzrule[1].change);
+
+  return 1;
+}
diff --git a/src/libc/newlib/src/time/tzvars.c b/src/libc/newlib/src/time/tzvars.c
new file mode 100644
index 0000000..aabf3c4
--- /dev/null
+++ b/src/libc/newlib/src/time/tzvars.c
@@ -0,0 +1,9 @@
+#include <time.h>
+#include <sys/_tz_structs.h>
+
+/* Global timezone variables.  */
+
+/* Default timezone to GMT */
+char *_tzname[2] = {"GMT", "GMT"};
+int _daylight = 0;
+long _timezone = 0;