Index: sys/ddb/db_command.c
===================================================================
--- sys/ddb/db_command.c
+++ sys/ddb/db_command.c
@@ -481,11 +481,13 @@
 		db_disable_pager();
 
 	    db_lex_wspace = ((cmd->flag & CS_LEX_SPACE) != 0);
+	    db_lex_hex = ((cmd->flag & CS_LEX_HEX) != 0);
 	    db_cmd_radix = -1;
 
 	    (*cmd->fcn)(addr, have_addr, count, modif);
 
 	    db_lex_wspace = false;
+	    db_lex_hex = false;
 	    db_cmd_radix = -1;
 
 	    if (dopager)
Index: sys/ddb/db_lex.h
===================================================================
--- sys/ddb/db_lex.h
+++ sys/ddb/db_lex.h
@@ -45,6 +45,7 @@
 int	 db_read_token(void);
 void	 db_unread_token(int t);
 
+extern bool		db_lex_hex;
 extern bool		db_lex_wspace;
 extern db_expr_t	db_tok_number;
 #define	TOK_STRING_SIZE		120
@@ -86,5 +87,7 @@
 #define	tQUESTION	33
 #define	tBIT_NOT	34
 #define	tWSPACE		35
+#define	tCOLON		36
+#define	tCOLONCOLON	37
 
 #endif /* !_DDB_DB_LEX_H_ */
Index: sys/ddb/db_lex.c
===================================================================
--- sys/ddb/db_lex.c
+++ sys/ddb/db_lex.c
@@ -42,6 +42,7 @@
 #include <ddb/ddb.h>
 #include <ddb/db_lex.h>
 
+bool		db_lex_hex;
 bool		db_lex_wspace;
 
 static char	db_line[DB_MAXLINE];
@@ -183,13 +184,16 @@
 	    return (tWSPACE);
 	}
 
-	if (c >= '0' && c <= '9') {
+	if ((c >= '0' && c <= '9') ||
+	   (db_lex_hex &&
+	   ((c >= 'a' && c <= 'f') ||
+	   (c >= 'A' && c <= 'F')))) {
 	    /* number */
 	    int	r, digit = 0;
 
 	    if (db_cmd_radix != -1)
 		r = db_cmd_radix;
-	    else if (c > '0')
+	    else if (c != '0')
 		r = db_radix;
 	    else {
 		c = db_read_char();
@@ -318,6 +322,12 @@
 		}
 		db_unread_char(c);
 		return (tEXCL);
+	    case ':':
+		c = db_read_char();
+		if (c == ':')
+			return (tCOLONCOLON);
+		db_unread_char(c);
+		return (tCOLON);
 	    case ';':
 		return (tSEMI);
 	    case '&':
Index: sys/ddb/ddb.h
===================================================================
--- sys/ddb/ddb.h
+++ sys/ddb/ddb.h
@@ -122,6 +122,7 @@
 				 * at end */
 #define	CS_LEX_SPACE	0x4	/* Switch the lexer to explicitly yield
 				   whitespace (tWSPACE) during cmd. */
+#define	CS_LEX_HEX	0x8	/* Allow numbers starting with a-f */
 #define	CS_SET_DOT	0x100	/* set dot after command */
 	struct command_table *more; /* another level of command */
 	LIST_ENTRY(command) next; /* next entry in the command table */