diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 92a1237..cb90a87 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -14895,7 +14895,7 @@ useful if you have some other way of getting the stub to the target
 system, and you can put it somewhere in memory where it won't get
 clobbered by the download.
 
-@item target sim
+@item target sim @r{[}@var{simargs}@r{]} @r{...}
 @cindex built-in simulator target
 Builtin CPU simulator.  @value{GDBN} includes simulators for most architectures.
 In general,
@@ -17291,6 +17291,25 @@ well as the Angel monitor.
 Show the setting of RDI heartbeat packets.
 @end table
 
+@table @code
+@item target sim @r{[}@var{simargs}@r{]} @r{...}
+The @value{GDBN} ARM simulator accepts the following optional arguments.
+
+@table @code
+@item --swi-support=@var{type}
+Tell the simulator which SWI interfaces to support.
+@var{type} may be a comma separated list of the following values.
+The default value is @code{all}.
+
+@table @code
+@item none
+@item demon
+@item angel
+@item redboot
+@item all
+@end table
+@end table
+@end table
 
 @node M32R/D
 @subsection Renesas M32R/D and M32R/SDI
diff --git a/gdb/remote-sim.c b/gdb/remote-sim.c
index 9f1adc7..96b45de 100644
--- a/gdb/remote-sim.c
+++ b/gdb/remote-sim.c
@@ -889,7 +889,7 @@ init_gdbsim_ops (void)
 {
   gdbsim_ops.to_shortname = "sim";
   gdbsim_ops.to_longname = "simulator";
-  gdbsim_ops.to_doc = "Use the compiled-in simulator.";
+  gdbsim_ops.to_doc = "Use the compiled-in simulator.  Any arguments will be passed on to the simulator.";
   gdbsim_ops.to_open = gdbsim_open;
   gdbsim_ops.to_close = gdbsim_close;
   gdbsim_ops.to_detach = gdbsim_detach;