diff --git a/Makefile b/Makefile
index cdea9a2..280db78 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,8 @@ CFLAGS = -Wall -g
 
 BISON = bison
 
-DTC_OBJS = dtc.o livetree.o flattree.o data.o treesource.o fstree.o \
+DTC_OBJS = dtc.o flattree.o fstree.o data.o livetree.o \
+		srcpos.o treesource.o \
 		dtc-parser.tab.o lex.yy.o
 
 DEPFILES = $(DTC_OBJS:.o=.d)
diff --git a/dtc-lexer.l b/dtc-lexer.l
index 93f3268..45f66ef 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l
@@ -20,6 +20,7 @@
 
 %option noyywrap nounput yylineno
 
+%x INCLUDE
 %x CELLDATA
 %x BYTESTRING
 %x MEMRESERVE
@@ -32,8 +33,9 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 
 %{
 #include "dtc.h"
-
 #include "dtc-parser.tab.h"
+#include "srcposstack.h"
+
 
 /*#define LEXDEBUG	1*/
 
@@ -49,7 +51,27 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 
 %%
 
+#[ \t]*include		BEGIN(INCLUDE);
+
+<INCLUDE>[ \t]*		/* whitespace before file name */
+<INCLUDE>\"[^"\n]*\"	{
+			yytext[strlen(yytext) - 1] = 0;
+			if (!push_input_file(yytext + 1)) {
+				/* Some unrecoverable error.*/
+				exit(1);
+			}
+			BEGIN(INITIAL);
+		}
+
+
+<<EOF>>		{
+			if (!pop_input_file()) {
+				yyterminate();
+			}
+		}
+
 \"[^"]*\"	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("String: %s\n", yytext);
 			yylval.data = data_copy_escape_string(yytext+1,
@@ -59,6 +81,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 "/memreserve/"	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("Keyword: /memreserve/\n");
 			BEGIN(MEMRESERVE);
@@ -66,6 +89,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <MEMRESERVE>[0-9a-fA-F]+ {
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			if (yyleng > 2*sizeof(yylval.addr)) {
 				fprintf(stderr, "Address value %s too large\n",
@@ -78,12 +102,14 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <MEMRESERVE>";"	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("/MEMRESERVE\n");
 			BEGIN(INITIAL);
 			return ';';
 		}
 <CELLDATA>[bodh]# {
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			if (*yytext == 'b')
 				yylval.cbase = 2;
@@ -98,6 +124,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <CELLDATA>[0-9a-fA-F]+	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			yylval.str = strdup(yytext);
 			DPRINT("Cell: '%s'\n", yylval.str);
@@ -105,6 +132,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <CELLDATA>">"	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("/CELLDATA\n");
 			BEGIN(INITIAL);
@@ -112,6 +140,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <CELLDATA>\&{REFCHAR}*	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("Ref: %s\n", yytext+1);
 			yylval.str = strdup(yytext+1);
@@ -119,6 +148,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <BYTESTRING>[0-9a-fA-F]{2} {
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			yylval.byte = strtol(yytext, NULL, 16);
 			DPRINT("Byte: %02x\n", (int)yylval.byte);
@@ -126,6 +156,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 <BYTESTRING>"]"	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("/BYTESTRING\n");
 			BEGIN(INITIAL);
@@ -135,6 +166,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 ,		{ /* Technically this is a valid property name,
 		     but we'd rather use it as punctuation, so detect it
 		     here in preference */
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("Char (propname like): %c (\\x%02x)\n", yytext[0],
 				(unsigned)yytext[0]);
@@ -142,6 +174,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 {PROPCHAR}+	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("PropName: %s\n", yytext);
 			yylval.str = strdup(yytext);
@@ -149,6 +182,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 		}
 
 {PROPCHAR}+(@{UNITCHAR}+)? {
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("NodeName: %s\n", yytext);
 			yylval.str = strdup(yytext);
@@ -157,6 +191,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 
 
 [a-zA-Z_][a-zA-Z0-9_]*:	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("Label: %s\n", yytext);
 			yylval.str = strdup(yytext);
@@ -167,6 +202,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 <*>{WS}+	/* eat whitespace */
 
 <*>"/*"([^*]|\*+[^*/])*\*+"/"	{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			DPRINT("Comment: %s\n", yytext);
 			/* eat comments */
@@ -175,6 +211,7 @@ REFCHAR		({PROPCHAR}|{UNITCHAR}|[/@])
 <*>"//".*\n	/* eat line comments */
 
 <*>.		{
+			yylloc.filenum = srcpos_filenum;
 			yylloc.first_line = yylineno;
 			switch (yytext[0]) {
 				case '<':
diff --git a/dtc-parser.y b/dtc-parser.y
index a8902fc..39d9dac 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -23,6 +23,7 @@
 
 %{
 #include "dtc.h"
+#include "srcpos.h"
 
 int yylex(void);
 void yyerror(char const *);
@@ -178,7 +179,13 @@ label:		DT_LABEL	{ $$ = $1; }
 
 void yyerror (char const *s)
 {
-	fprintf (stderr, "%s at line %d\n", s, yylloc.first_line);
+	const char *fname = srcpos_filename_for_num(yylloc.filenum);
+
+	if (strcmp(fname, "-") == 0)
+		fname = "stdin";
+
+	fprintf(stderr, "%s:%d %s\n",
+		fname, yylloc.first_line, s);
 }
 
 
diff --git a/dtc.c b/dtc.c
index 051a68b..a009605 100644
--- a/dtc.c
+++ b/dtc.c
@@ -19,6 +19,7 @@
  */
 
 #include "dtc.h"
+#include "srcpos.h"
 
 char *join_path(char *path, char *name)
 {
@@ -61,21 +62,6 @@ void fill_fullpaths(struct node *tree, char *prefix)
 		fill_fullpaths(child, tree->fullpath);
 }
 
-static FILE *dtc_open_file(char *fname)
-{
-	FILE *f;
-
-	if (streq(fname, "-"))
-		f = stdin;
-	else
-		f = fopen(fname, "r");
-
-	if (! f)
-		die("Couldn't open \"%s\": %s\n", fname, strerror(errno));
-
-	return f;
-}
-
 static void usage(void)
 {
 	fprintf(stderr, "Usage:\n");
@@ -166,8 +152,7 @@ int main(int argc, char *argv[])
 		inform, outform, arg);
 
 	if (streq(inform, "dts")) {
-		inf = dtc_open_file(arg);
-		bi = dt_from_source(inf);
+		bi = dt_from_source(arg);
 	} else if (streq(inform, "fs")) {
 		bi = dt_from_fs(arg);
 	} else if(streq(inform, "dtb")) {
diff --git a/dtc.h b/dtc.h
index e3e2863..7ed3df2 100644
--- a/dtc.h
+++ b/dtc.h
@@ -223,7 +223,7 @@ struct boot_info *dt_from_blob(FILE *f);
 /* Tree source */
 
 void dt_to_source(FILE *f, struct boot_info *bi);
-struct boot_info *dt_from_source(FILE *f);
+struct boot_info *dt_from_source(const char *f);
 
 /* FS trees */
 
diff --git a/srcpos.c b/srcpos.c
new file mode 100644
index 0000000..352b0fe
--- /dev/null
+++ b/srcpos.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 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
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *                                                                   USA
+ */
+
+#include "dtc.h"
+#include "srcpos.h"
+
+
+/*
+ * Record the complete unique set of opened file names.
+ * Primarily used to cache source position file names.
+ */
+#define MAX_N_FILE_NAMES	(100)
+
+const char *file_names[MAX_N_FILE_NAMES];
+static int n_file_names = 0;
+
+/*
+ * Like yylineno, this is the current open file pos.
+ */
+
+int srcpos_filenum = -1;
+
+
+
+FILE *dtc_open_file(const char *fname)
+{
+	FILE *f;
+
+	if (lookup_file_name(fname, 1) < 0)
+		die("Too many files opened\n");
+
+	if (streq(fname, "-"))
+		f = stdin;
+	else
+		f = fopen(fname, "r");
+
+	if (! f)
+		die("Couldn't open \"%s\": %s\n", fname, strerror(errno));
+
+	return f;
+}
+
+
+
+/*
+ * Locate and optionally add filename fname in the file_names[] array.
+ *
+ * If the filename is currently not in the array and the boolean
+ * add_it is non-zero, an attempt to add the filename will be made.
+ *
+ * Returns;
+ *    Index [0..MAX_N_FILE_NAMES) where the filename is kept
+ *    -1 if the name can not be recorded
+ */
+
+int lookup_file_name(const char *fname, int add_it)
+{
+	int i;
+
+	for (i = 0; i < n_file_names; i++) {
+		if (strcmp(file_names[i], fname) == 0)
+			return i;
+	}
+
+	if (add_it) {
+		if (n_file_names < MAX_N_FILE_NAMES) {
+			file_names[n_file_names] = strdup(fname);
+			return n_file_names++;
+		}
+	}
+
+	return -1;
+}
+
+
+const char *srcpos_filename_for_num(int filenum)
+{
+	if (0 <= filenum && filenum < n_file_names) {
+		return file_names[filenum];
+	}
+
+	return 0;
+}
+
+
+const char *srcpos_get_filename(void)
+{
+	return srcpos_filename_for_num(srcpos_filenum);
+}
diff --git a/srcpos.h b/srcpos.h
new file mode 100644
index 0000000..d591e7e
--- /dev/null
+++ b/srcpos.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 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
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *                                                                   USA
+ */
+
+/*
+ * Augment the standard YYLTYPE with a filenum index into an
+ * array of all opened filenames.
+ */
+
+#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED
+typedef struct YYLTYPE {
+    int first_line;
+    int first_column;
+    int last_line;
+    int last_column;
+    int filenum;
+} YYLTYPE;
+
+#define YYLTYPE_IS_DECLARED	1
+#define YYLTYPE_IS_TRIVIAL	1
+#endif
+
+
+#define YYLLOC_DEFAULT(Current, Rhs, N)					\
+    do									\
+      if (YYID (N))							\
+	{								\
+	  (Current).first_line   = YYRHSLOC (Rhs, 1).first_line;	\
+	  (Current).first_column = YYRHSLOC (Rhs, 1).first_column;	\
+	  (Current).last_line    = YYRHSLOC (Rhs, N).last_line;		\
+	  (Current).last_column  = YYRHSLOC (Rhs, N).last_column;	\
+	  (Current).filenum      = YYRHSLOC (Rhs, N).filenum;		\
+	}								\
+      else								\
+	{								\
+	  (Current).first_line   = (Current).last_line   =		\
+	    YYRHSLOC (Rhs, 0).last_line;				\
+	  (Current).first_column = (Current).last_column =		\
+	    YYRHSLOC (Rhs, 0).last_column;				\
+	  (Current).filenum      = YYRHSLOC (Rhs, 0).filenum;		\
+	}								\
+    while (YYID (0))
+
+
+
+
+extern int srcpos_filenum;
+
+extern int push_input_file(const char *filename);
+extern int pop_input_file(void);
+
+extern FILE *dtc_open_file(const char *fname);
+extern int lookup_file_name(const char *fname, int add_it);
+extern const char *srcpos_filename_for_num(int filenum);
+const char *srcpos_get_filename(void);
+
diff --git a/srcposstack.h b/srcposstack.h
new file mode 100644
index 0000000..a95a179
--- /dev/null
+++ b/srcposstack.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 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
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *                                                                   USA
+ */
+
+#include "srcpos.h"
+
+
+/*
+ * This code should only be included into the lexical analysis.
+ * It references global context symbols that are only present
+ * in the generated lex.yy,c file.
+ */
+
+#ifdef FLEX_SCANNER
+
+
+/*
+ * Stack of nested include file contexts.
+ */
+
+struct incl_file {
+	int filenum;
+	FILE *file;
+	YY_BUFFER_STATE yy_prev_buf;
+	int yy_prev_lineno;
+	struct incl_file *prev;
+};
+
+struct incl_file *incl_file_stack;
+
+
+/*
+ * Detect infinite include recursion.
+ */
+#define MAX_INCLUDE_DEPTH	(100)
+
+static int incl_depth = 0;
+
+
+
+int push_input_file(const char *filename)
+{
+	FILE *f;
+	struct incl_file *incl_file;
+
+	if (!filename) {
+		yyerror("No include file name given.");
+		return 0;
+	}
+
+	if (incl_depth++ >= MAX_INCLUDE_DEPTH) {
+		yyerror("Includes nested too deeply");
+		return 0;
+	}
+
+	f = dtc_open_file(filename);
+
+	incl_file = malloc(sizeof(struct incl_file));
+	if (!incl_file) {
+		yyerror("Can not allocate include file space.");
+		return 0;
+	}
+
+	/*
+	 * Save current context.
+	 */
+	incl_file->yy_prev_buf = YY_CURRENT_BUFFER;
+	incl_file->yy_prev_lineno = yylineno;
+	incl_file->filenum = srcpos_filenum;
+	incl_file->file = yyin;
+	incl_file->prev = incl_file_stack;
+
+	incl_file_stack = incl_file;
+
+	/*
+	 * Establish new context.
+	 */
+	srcpos_filenum = lookup_file_name(filename, 0);
+	yylineno = 1;
+	yyin = f;
+	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
+
+	return 1;
+}
+
+
+int pop_input_file(void)
+{
+	struct incl_file *incl_file;
+
+	if (incl_file_stack == 0)
+		return 0;
+
+	fclose(yyin);
+
+	/*
+	 * Pop.
+	 */
+	--incl_depth;
+	incl_file = incl_file_stack;
+	incl_file_stack = incl_file->prev;
+
+	/*
+	 * Recover old context.
+	 */
+	yy_delete_buffer(YY_CURRENT_BUFFER);
+	yy_switch_to_buffer(incl_file->yy_prev_buf);
+	yylineno = incl_file->yy_prev_lineno;
+	srcpos_filenum = incl_file->filenum;
+	yyin = incl_file->file;
+
+	/*
+	 * Free old state.
+	 */
+	free(incl_file);
+
+	if (YY_CURRENT_BUFFER == 0)
+		return 0;
+
+	return 1;
+}
+
+#endif	/* FLEX_SCANNER */
diff --git a/treesource.c b/treesource.c
index e9bbaa5..c067b20 100644
--- a/treesource.c
+++ b/treesource.c
@@ -19,6 +19,7 @@
  */
 
 #include "dtc.h"
+#include "srcpos.h"
 
 extern FILE *yyin;
 extern int yyparse(void);
@@ -26,11 +27,12 @@ extern void yyerror(char const *);
 
 struct boot_info *the_boot_info;
 
-struct boot_info *dt_from_source(FILE *f)
+struct boot_info *dt_from_source(const char *fname)
 {
 	the_boot_info = NULL;
 
-	yyin = f;
+	push_input_file(fname);
+
 	if (yyparse() != 0)
 		return NULL;