Clean up start of erl_prim_loader

The 'init' module fetches command line parameters and passes them
to erl_prim_loader:start/3.

The code can be simplified if 'init' calls a new
erl_prim_loader:start/0 function that itself fetches the necessary
command line parameters. Also remove the documentation for the start()
function, since it there is no way that it can be usefully called by
a user application.

While we are at it, also get rid of '-id' command line parameter,
which is fetched and stored but never actually used.

3 files changed, 56 insertions, 100 deletions

diff --git a/erts/doc/src/erl_prim_loader.xml b/erts/doc/src/erl_prim_loader.xml
index db4f132609..6fdec8c89e 100644
--- a/erts/doc/src/erl_prim_loader.xml
+++ b/erts/doc/src/erl_prim_loader.xml
@@ -50,36 +50,9 @@
      <c>-loader_debug</c> are also experimental</p></warning>
 
   </description>
-  <datatypes>
-    <datatype>
-      <name name="host"/>
-    </datatype>
-  </datatypes>
 
   <funcs>
     <func>
-      <name name="start" arity="3"/>
-      <fsummary>Start the Erlang low level loader</fsummary>
-      <desc>
-        <p>Starts the Erlang low level loader. This function is called
-          by the <c>init</c> process (and module). The <c>init</c>
-          process reads the command line flags <c>-id <anno>Id</anno></c>,
-          <c>-loader <anno>Loader</anno></c>, and <c>-hosts <anno>Hosts</anno></c>. These are
-          the arguments supplied to the <c>start/3</c> function.</p>
-        <p>If <c>-loader</c> is not given, the default loader is
-          <c>efile</c> which tells the system to read from the file
-          system.</p>
-        <p>If <c>-loader</c> is <c>inet</c>, the <c>-id <anno>Id</anno></c>,
-          <c>-hosts <anno>Hosts</anno></c>, and <c>-setcookie Cookie</c> flags must
-          also be supplied. <c><anno>Hosts</anno></c> identifies hosts which this
-          node can contact in order to load modules. One Erlang
-          runtime system with a <c>erl_boot_server</c> process must be
-          started on each of hosts given in <c><anno>Hosts</anno></c> in order to
-          answer the requests. See <seealso
-          marker="kernel:erl_boot_server">erl_boot_server(3)</seealso>.</p>
-      </desc>
-    </func>
-    <func>
       <name name="get_file" arity="1"/>
       <fsummary>Get a file</fsummary>
       <desc>
@@ -189,17 +162,12 @@
         <p>Specifies which other Erlang nodes the <c>inet</c> loader
           can use. This flag is mandatory if the <c>-loader inet</c>
           flag is present. On each host, there must be on Erlang node
-          with the <c>erl_boot_server</c> which handles the load
-          requests. <c>Hosts</c> is a list of IP addresses (hostnames
+          with the <seealso
+          marker="kernel:erl_boot_server">erl_boot_server(3)</seealso>
+	  which handles the load requests.
+	  <c>Hosts</c> is a list of IP addresses (hostnames
           are not acceptable).</p>
       </item>
-      <tag><c>-id Id</c></tag>
-      <item>
-        <p>Specifies the identity of the Erlang runtime system. If
-          the system runs as a distributed node, <c>Id</c> must be
-          identical to the name supplied with the <c>-sname</c> or
-          <c>-name</c> distribution flags.</p>
-      </item>
       <tag><c>-setcookie Cookie</c></tag>
       <item>
         <p>Specifies the cookie of the Erlang runtime system. This flag
diff --git a/erts/preloaded/src/erl_prim_loader.erl b/erts/preloaded/src/erl_prim_loader.erl
index a8d1e4df76..041b54ee0d 100644
--- a/erts/preloaded/src/erl_prim_loader.erl
+++ b/erts/preloaded/src/erl_prim_loader.erl
@@ -42,7 +42,7 @@
 -include("inet_boot.hrl").
 
 %% Public
--export([start/3, set_path/1, get_path/0, get_file/1,
+-export([start/0, set_path/1, get_path/0, get_file/1,
          list_dir/1, read_file_info/1, read_link_info/1, get_cwd/0, get_cwd/1]).
 
 %% Used by erl_boot_server
@@ -64,9 +64,8 @@
 -record(state, 
         {loader            :: 'efile' | 'inet',
          hosts = []        :: [host()], % hosts list (to boot from)
-         id,                      % not used any more?
          data              :: 'noport' | port(), % data port etc
-         timeout           :: timeout(),         % idle timeout
+         timeout           :: timeout(),	 % idle timeout
 	 %% Number of timeouts before archives are released
 	 n_timeouts        :: non_neg_integer(),
          prim_state        :: prim_state()}).    % state for efile code loader
@@ -102,26 +101,13 @@ debug(#prim_state{debug = Deb}, Term) ->
 %%% Interface Functions. 
 %%% --------------------------------------------------------
 
--spec start(Id, Loader, Hosts) ->
+-spec start() ->
 	    {'ok', Pid} | {'error', What} when
-      Id :: term(),
-      Loader :: atom() | string(),
-      Hosts :: Host | [Host],
-      Host :: host(),
       Pid :: pid(),
       What :: term().
-start(Id, Pgm, Hosts) when is_atom(Hosts) ->
-    start(Id, Pgm, [Hosts]);
-start(Id, Pgm0, Hosts) ->
-    Pgm = if
-              is_atom(Pgm0) ->
-                  atom_to_list(Pgm0);
-              true ->
-                  Pgm0
-          end,
+start() ->
     Self = self(),
-    Pid = spawn_link(fun() -> start_it(Pgm, Id, Self, Hosts) end),
-    register(erl_prim_loader, Pid),
+    Pid = spawn_link(fun() -> start_it(Self) end),
     receive
         {Pid,ok} ->
             {ok,Pid};
@@ -129,26 +115,40 @@ start(Id, Pgm0, Hosts) ->
             {error,Reason}
     end.
 
-%% Hosts must be a list of form ['1.2.3.4' ...]
-start_it("inet", Id, Pid, Hosts) ->
+start_it(Parent) ->
     process_flag(trap_exit, true),
-    ?dbg(inet, {Id,Pid,Hosts}),
+    register(erl_prim_loader, self()),
+    Loader = case init:get_argument(loader) of
+		 {ok,[[Loader0]]} ->
+		     Loader0;
+		 error ->
+		     "efile"
+	     end,
+    case Loader of
+	"efile" -> start_efile(Parent);
+	"inet" -> start_inet(Parent)
+    end.
+
+%% Hosts must be a list of form ['1.2.3.4' ...]
+start_inet(Parent) ->
+    Hosts = case init:get_argument(hosts) of
+		{ok,[Hosts0]} -> Hosts0;
+		_ -> []
+	    end,
     AL = ipv4_list(Hosts),
     ?dbg(addresses, AL),
     {ok,Tcp} = find_master(AL),
-    init_ack(Pid),
+    init_ack(Parent),
     PS = prim_init(),
     State = #state {loader = inet,
                     hosts = AL,
-                    id = Id,
                     data = Tcp,
                     timeout = ?IDLE_TIMEOUT,
 		    n_timeouts = ?N_TIMEOUTS,
                     prim_state = PS},
-    loop(State, Pid, []);
+    loop(State, Parent, []).
 
-start_it("efile", Id, Pid, _Hosts) ->
-    process_flag(trap_exit, true),
+start_efile(Parent) ->
     {ok, Port} = prim_file:start(),
     %% Check that we started in a valid directory.
     case prim_file:get_cwd(Port) of
@@ -159,15 +159,14 @@ start_it("efile", Id, Pid, _Hosts) ->
 	    erlang:display(Report),
 	    exit({error, invalid_current_directory});
 	_ ->
-	    init_ack(Pid)
+	    init_ack(Parent)
     end,
     PS = prim_init(),
     State = #state {loader = efile,
-                    id = Id,
                     data = Port,
                     timeout = infinity,
                     prim_state = PS},
-    loop(State, Pid, []).
+    loop(State, Parent, []).
 
 init_ack(Pid) ->
     Pid ! {self(),ok},
@@ -1262,11 +1261,7 @@ string_split2(_, _Ext, _RevBase, _RevTop, SaveFile, SaveExt, SaveTop) ->
 
 %% Parse list of ipv4 addresses 
 ipv4_list([H | T]) ->
-    IPV = if is_atom(H) -> ipv4_address(atom_to_list(H));
-             is_list(H) -> ipv4_address(H);
-             true -> {error,einal}
-          end,
-    case IPV of
+    case ipv4_address(H) of
         {ok,IP} -> [IP | ipv4_list(T)];
         _ -> ipv4_list(T)
     end;
diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl
index b5c1d46e60..197bc5fde8 100644
--- a/erts/preloaded/src/init.erl
+++ b/erts/preloaded/src/init.erl
@@ -23,7 +23,6 @@
 %% a local file or distributed from another erlang node.
 %% 
 %% Flags:
-%%        -id Identity   : identity of the system.
 %%        -boot File     : Absolute file name of the boot script.
 %%        -boot_var Var Value
 %%                       : $Var in the boot script is expanded to
@@ -693,17 +692,15 @@ sleep(T) -> receive after T -> ok end.
 %%% The loader shall run for ever!
 %%% -------------------------------------------------
 
-start_prim_loader(Init,Id,Pgm,Nodes,Path,{Pa,Pz}) ->
-    case erl_prim_loader:start(Id,Pgm,Nodes) of
-	{ok,Pid} when Path =:= false ->
-	    InitPath = append(Pa,["."|Pz]),
-	    erl_prim_loader:set_path(InitPath),
-	    add_to_kernel(Init,Pid),
-	    Pid;
+start_prim_loader(Init, Path0, {Pa,Pz}) ->
+    Path = case Path0 of
+	       false -> Pa ++ ["."|Pz];
+	       _ -> Path0
+	   end,
+    case erl_prim_loader:start() of
 	{ok,Pid} ->
 	    erl_prim_loader:set_path(Path),
-	    add_to_kernel(Init,Pid),
-	    Pid;
+	    add_to_kernel(Init, Pid);
 	{error,Reason} ->
 	    erlang:display({"cannot start loader",Reason}),
 	    exit(Reason)
@@ -717,13 +714,6 @@ add_to_kernel(Init,Pid) ->
 	    ok
     end.
 
-prim_load_flags(Flags) ->
-    PortPgm = get_flag(loader, Flags, <<"efile">>),
-    Hosts = get_flag_list(hosts, Flags, []),
-    Id = get_flag(id, Flags, none),
-    Path = get_flag_list(path, Flags, false),
-    {PortPgm, Hosts, Id, Path}.
-
 %%% -------------------------------------------------
 %%% The boot process fetches a boot script and loads
 %%% all modules specified and starts spec. processes.
@@ -736,12 +726,10 @@ do_boot(Flags,Start) ->
 
 do_boot(Init,Flags,Start) ->
     process_flag(trap_exit,true),
-    {Pgm0,Nodes,Id,Path} = prim_load_flags(Flags),
     Root = get_root(Flags),
+    Path = get_flag_list(path, Flags, false),
     {Pa,Pz} = PathFls = path_flags(Flags),
-    Pgm = b2s(Pgm0),
-    _Pid = start_prim_loader(Init,b2a(Id),Pgm,bs2as(Nodes),
-			     bs2ss(Path),PathFls),
+    start_prim_loader(Init, bs2ss(Path), PathFls),
     BootFile = bootfile(Flags,Root),
     BootList = get_boot(BootFile,Root),
     LoadMode = b2a(get_flag(mode, Flags, false)),
@@ -854,11 +842,18 @@ eval_script([{kernel_load_completed}|T], #es{load_mode=Mode}=Es0) ->
 	     _ -> Es0#es{prim_load=false}
 	 end,
     eval_script(T, Es);
-eval_script([{primLoad,Mods}|T], #es{prim_load=PrimLoad}=Es)
+eval_script([{primLoad,[Mod]}|T], #es{prim_load=true}=Es) ->
+    %% Common special case (loading of error_handler). Nothing
+    %% to gain by parallel loading.
+    File = atom_to_list(Mod) ++ objfile_extension(),
+    {ok,Full} = load_mod(Mod, File),
+    init ! {self(),loaded,{Mod,Full}}, % Tell init about loaded module
+    eval_script(T, Es);
+eval_script([{primLoad,Mods}|T], #es{init=Init,prim_load=PrimLoad}=Es)
   when is_list(Mods) ->
     case PrimLoad of
 	true ->
-	    load_modules(Mods);
+	    load_modules(Mods, Init);
 	false ->
 	    %% Do not load now, code_server does that dynamically!
 	    ok
@@ -878,12 +873,12 @@ eval_script([], #es{}) ->
 eval_script(What, #es{}) ->
     exit({'unexpected command in bootfile',What}).
 
-load_modules([Mod|Mods]) ->
+load_modules([Mod|Mods], Init) ->
     File = concat([Mod,objfile_extension()]),
     {ok,Full} = load_mod(Mod,File),
-    init ! {self(),loaded,{Mod,Full}},  %% Tell init about loaded module
-    load_modules(Mods);
-load_modules([]) ->
+    Init ! {self(),loaded,{Mod,Full}},	%Tell init about loaded module
+    load_modules(Mods, Init);
+load_modules([], _) ->
     ok.
 
 make_path(Pa, Pz, Path, Vars) ->
@@ -1244,8 +1239,6 @@ concat([S|T]) ->
 concat([]) ->
     [].
 
-append(L, Z) -> L ++ Z.
-
 append([E]) -> E;
 append([H|T]) ->
     H ++ append(T);