Initial source

15 files changed, 597 insertions, 0 deletions

diff --git a/util/Makerules b/util/Makerules
new file mode 100644
index 00000000..0d6a2315
--- /dev/null
+++ b/util/Makerules
@@ -0,0 +1,32 @@
+#
+# Copyright (c) 1994 The University of Utah and
+# the Computer Systems Laboratory (CSL).  All rights reserved.
+#
+# Permission to use, copy, modify and distribute this software and its
+# documentation is hereby granted, provided that both the copyright
+# notice and this permission notice appear in all copies of the
+# software, derivative works or modified versions, and any portions
+# thereof, and that both notices appear in supporting documentation.
+#
+# THE UNIVERSITY OF UTAH AND CSS ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+# IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSS DISCLAIM ANY LIABILITY OF
+# ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+#
+# CSS requests users of this software to return to css-dist@cs.utah.edu any
+# improvements that they make and grant CSS redistribution rights.
+#
+#      Author: Bryan Ford, University of Utah CSS
+#
+ifndef _kernel_util_makerules_
+_kernel_util_makerules = yes
+
+
+# Old defines that I hope to phase out
+DEFINES += -DMACH_KERNEL
+
+
+# Include the makefile containing the generic rules.
+include $(GSRCDIR)/Makerules
+
+
+endif
diff --git a/util/about_to_die.c b/util/about_to_die.c
new file mode 100644
index 00000000..9b039ccb
--- /dev/null
+++ b/util/about_to_die.c
@@ -0,0 +1,34 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+/* Call this to declare intention to die,
+   before doing final printfs and such.
+   The default implementation does nothing,
+   but typical actions might be to restore the video mode
+   to a standard setting, or stop other processors.
+   Note that this might very well be called several times
+   before die() is finally called.  */
+void about_to_die(int exit_code)
+{
+}
+
diff --git a/util/config.h b/util/config.h
new file mode 100644
index 00000000..23b2bf63
--- /dev/null
+++ b/util/config.h
@@ -0,0 +1,23 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+/* This file is just an empty default config.h file.  */
diff --git a/util/cpu.c b/util/cpu.c
new file mode 100644
index 00000000..0e45ac4f
--- /dev/null
+++ b/util/cpu.c
@@ -0,0 +1,27 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+#include "cpu.h"
+
+struct cpu cpu[NCPUS];
+
diff --git a/util/cpu.h b/util/cpu.h
new file mode 100644
index 00000000..357f6d72
--- /dev/null
+++ b/util/cpu.h
@@ -0,0 +1,41 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+#ifndef	_UTIL_CPU_H_
+#define _UTIL_CPU_H_
+
+#include "cpus.h"
+
+
+/* There's one of these data structures per processor.  */
+struct cpu
+{
+#define cpu_sub(name) struct cpu_##name name;
+#include "cpu_subs.h"
+#undef cpu_sub
+int dummy;
+};
+
+extern struct cpu cpu[NCPUS];
+
+
+#endif _UTIL_CPU_H_
diff --git a/util/cpu_init.c b/util/cpu_init.c
new file mode 100644
index 00000000..c59824ba
--- /dev/null
+++ b/util/cpu_init.c
@@ -0,0 +1,40 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+#include "cpu.h"
+
+void cpu_init(struct cpu *cpu)
+{
+#define cpu_sub(name) cpu_##name##_init(cpu);
+#include "cpu_subs.h"
+#undef cpu_sub
+}
+
+void cpus_init()
+{
+	int n;
+
+	for (n = 0; n < NCPUS; n++)
+		cpu_init(&cpu[n]);
+}
+
diff --git a/util/cpu_subs.h b/util/cpu_subs.h
new file mode 100644
index 00000000..850ef38f
--- /dev/null
+++ b/util/cpu_subs.h
@@ -0,0 +1,23 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+/* This file is just a terminator for the set of cpu_subs.h headers.  */
diff --git a/util/cpus.h b/util/cpus.h
new file mode 100644
index 00000000..355ecdb1
--- /dev/null
+++ b/util/cpus.h
@@ -0,0 +1,27 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+/* Default cpus.h sets things up for a uniprocessor.  */
+#define NCPUS 1
+#undef MULTIPROCESSOR
+
diff --git a/util/debug.h b/util/debug.h
new file mode 100644
index 00000000..d61502b7
--- /dev/null
+++ b/util/debug.h
@@ -0,0 +1,81 @@
+/* 
+ * Copyright (c) 1995-1993 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+/*
+ *	File:	debug.h
+ *	Author:	Bryan Ford
+ *
+ *	This file contains definitions for kernel debugging,
+ *	which are compiled in on the DEBUG symbol.
+ *
+ */
+#ifndef _MACH_UTIL_DEBUG_H_
+#define _MACH_UTIL_DEBUG_H_
+
+#include <mach/macro_help.h>
+
+
+#ifdef DEBUG
+
+extern void panic(const char *fmt, ...);
+
+#define here() printf("@ %s:%d\n", __FILE__, __LINE__)
+#define message(args) ({ printf("@ %s:%d: ", __FILE__, __LINE__); printf args; printf("\n"); })
+
+#define otsan() panic("%s:%d: off the straight and narrow!", __FILE__, __LINE__)
+
+#define assert(v)							\
+	MACRO_BEGIN							\
+		if (!(v))						\
+			panic("%s:%d: failed assertion `"#v"'\n",	\
+				__FILE__, __LINE__);			\
+	MACRO_END
+
+#define do_debug(stmt) stmt
+
+#define debugmsg(args) \
+	({ printf("%s:%d: ", __FILE__, __LINE__); printf args; printf("\n"); })
+
+#define struct_id_decl		unsigned struct_id;
+#define struct_id_init(p,id)	((p)->struct_id = (id))
+#define struct_id_denit(p)	((p)->struct_id = 0)
+#define struct_id_verify(p,id) \
+	({ if ((p)->struct_id != (id)) \
+		panic("%s:%d: "#p" (%08x) struct_id should be "#id" (%08x), is %08x\n", \
+			__FILE__, __LINE__, (p), (id), (p->struct_id)); \
+	})
+
+#else !DEBUG
+
+#define otsan()
+#define assert(v)
+#define do_debug(stmt)
+#define debugmsg(args)
+
+#define struct_id_decl
+#define struct_id_init(p,id)
+#define struct_id_denit(p)
+#define struct_id_verify(p,id)
+
+#endif !DEBUG
+
+#endif _MACH_UTIL_DEBUG_H_
diff --git a/util/die.c b/util/die.c
new file mode 100644
index 00000000..c2eeeaf5
--- /dev/null
+++ b/util/die.c
@@ -0,0 +1,54 @@
+/* 
+ * Copyright (c) 1995-1994 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+#include <stdarg.h>
+
+/* Note: These routines are deprecated and should not be used anymore.
+   Use panic() instead.  */
+void die(const char *fmt, ...)
+{
+	int exit_code = fmt != 0;
+
+	about_to_die(exit_code);
+
+	if (fmt)
+	{
+		va_list vl;
+
+		va_start(vl, fmt);
+		vprintf(fmt, vl);
+		va_end(vl);
+
+		putchar('\n');
+
+		exit(exit_code);
+	}
+	else
+		exit(exit_code);
+}
+
+void die_no_mem(void)
+{
+	die("Not enough memory.");
+}
+
diff --git a/util/panic.c b/util/panic.c
new file mode 100644
index 00000000..2df88396
--- /dev/null
+++ b/util/panic.c
@@ -0,0 +1,48 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+void panic(const char *fmt, ...)
+{
+	int exit_code = fmt != 0;
+
+	about_to_die(exit_code);
+
+	if (fmt)
+	{
+		va_list vl;
+
+		va_start(vl, fmt);
+		vprintf(fmt, vl);
+		va_end(vl);
+
+		putchar('\n');
+
+		exit(exit_code);
+	}
+	else
+		exit(exit_code);
+}
+
diff --git a/util/phys_mem.h b/util/phys_mem.h
new file mode 100644
index 00000000..2e18a6bb
--- /dev/null
+++ b/util/phys_mem.h
@@ -0,0 +1,34 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+#ifndef _UTIL_PHYS_MEM_H_
+#define _UTIL_PHYS_MEM_H_
+
+#include <mach/machine/vm_types.h>
+
+
+/* This always holds the physical address
+   of the top of known physical memory.  */
+extern vm_offset_t phys_mem_max;
+
+
+#endif _UTIL_PHYS_MEM_H_
diff --git a/util/putchar.c b/util/putchar.c
new file mode 100644
index 00000000..18f0f06c
--- /dev/null
+++ b/util/putchar.c
@@ -0,0 +1,28 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+int putchar(int c)
+{
+	cnputc(c);
+}
+
diff --git a/util/puts.c b/util/puts.c
new file mode 100644
index 00000000..c0eec03e
--- /dev/null
+++ b/util/puts.c
@@ -0,0 +1,37 @@
+/* 
+ * Copyright (c) 1995 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+/* Simple puts() implementation that just uses putchar().
+   Note that our libc's printf() is implemented
+   in terms of only puts() and putchar(), so that's all we need.  */
+int puts(const char *s)
+{
+	while (*s)
+	{
+		putchar(*s);
+		s++;
+	}
+	putchar('\n');
+	return 0;
+}
+
diff --git a/util/ref_count.h b/util/ref_count.h
new file mode 100644
index 00000000..b6d34048
--- /dev/null
+++ b/util/ref_count.h
@@ -0,0 +1,68 @@
+/* 
+ * Copyright (c) 1995-1993 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+/*
+ *	File:	refcount.h
+ *
+ *	This defines the system-independent atomic reference count data type.
+ *	(This file will often be overridden
+ *	by better machine-dependent implementations.)
+ *
+ */
+
+#ifndef	_KERN_REF_COUNT_H_
+#define _KERN_REF_COUNT_H_
+
+#include <mach/macro_help.h>
+
+#include "simple_lock.h"
+
+
+struct ref_count {
+	decl_simple_lock_data(,lock)	/* lock for reference count */
+	int		count;		/* number of references */
+};
+
+#define ref_count_init(refcount, refs)			\
+	MACRO_BEGIN					\
+		simple_lock_init(&(refcount)->lock);	\
+		((refcount)->count = (refs));		\
+	MACRO_END
+
+#define ref_count_take(refcount)			\
+	MACRO_BEGIN					\
+		simple_lock(&(refcount)->lock);		\
+		(refcount)->count++;			\
+		simple_unlock(&(refcount)->lock);	\
+	MACRO_END
+
+#define ref_count_drop(refcount, func)			\
+	MACRO_BEGIN					\
+		int new_value;				\
+		simple_lock(&(refcount)->lock);		\
+		new_value = --(refcount)->count;	\
+		simple_unlock(&(refcount)->lock);	\
+		if (new_value == 0) { func; }		\
+	MACRO_END
+
+
+#endif _KERN_REF_COUNT_H_