1 files changed, 116 insertions, 0 deletions
diff --git a/sys/ddb/db_access.c b/sys/ddb/db_access.c
new file mode 100644
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--- /dev/null
+++ b/sys/ddb/db_access.c
@@ -0,0 +1,116 @@
+/* 
+ * Mach Operating System
+ * Copyright (c) 1991,1990 Carnegie Mellon University
+ * 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.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ */
+/*
+ * HISTORY
+ * $Log: db_access.c,v $
+ * Revision 1.1  1992/03/25  21:44:50  pace
+ * Initial revision
+ *
+ * Revision 2.3  91/02/05  17:05:44  mrt
+ * 	Changed to new Mach copyright
+ * 	[91/01/31  16:16:22  mrt]
+ * 
+ * Revision 2.2  90/08/27  21:48:20  dbg
+ * 	Fix type declarations.
+ * 	[90/08/07            dbg]
+ * 	Created.
+ * 	[90/07/25            dbg]
+ * 
+ */
+/*
+ *	Author: David B. Golub, Carnegie Mellon University
+ *	Date:	7/90
+ */
+#include "param.h"
+#include "proc.h"
+#include <machine/db_machdep.h>		/* type definitions */
+
+/*
+ * Access unaligned data items on aligned (longword)
+ * boundaries.
+ */
+
+extern void	db_read_bytes();	/* machine-dependent */
+extern void	db_write_bytes();	/* machine-dependent */
+
+int db_extend[] = {	/* table for sign-extending */
+	0,
+	0xFFFFFF80,
+	0xFFFF8000,
+	0xFF800000
+};
+
+db_expr_t
+db_get_value(addr, size, is_signed)
+	db_addr_t	addr;
+	register int	size;
+	boolean_t	is_signed;
+{
+	char		data[sizeof(int)];
+	register db_expr_t value;
+	register int	i;
+
+	db_read_bytes(addr, size, data);
+
+	value = 0;
+#if	BYTE_MSF
+	for (i = 0; i < size; i++)
+#else	/* BYTE_LSF */
+	for (i = size - 1; i >= 0; i--)
+#endif
+	{
+	    value = (value << 8) + (data[i] & 0xFF);
+	}
+	    
+	if (size < 4) {
+	    if (is_signed && (value & db_extend[size]) != 0)
+		value |= db_extend[size];
+	}
+	return (value);
+}
+
+void
+db_put_value(addr, size, value)
+	db_addr_t	addr;
+	register int	size;
+	register db_expr_t value;
+{
+	char		data[sizeof(int)];
+	register int	i;
+
+#if	BYTE_MSF
+	for (i = size - 1; i >= 0; i--)
+#else	/* BYTE_LSF */
+	for (i = 0; i < size; i++)
+#endif
+	{
+	    data[i] = value & 0xFF;
+	    value >>= 8;
+	}
+
+	db_write_bytes(addr, size, data);
+}
+