From b44534221fe11e7aaabd6e3f60361285e1fc8e40 Mon Sep 17 00:00:00 2001
From: Mikael Pettersson <mikpelinux@gmail.com>
Date: Wed, 8 Jul 2020 13:44:14 +0200
Subject: [PATCH] sim: handle exit_group() syscall, exit with simulated
 program's exit status

---
 erlang/apps/sim/src/sim.erl        |  5 ++++-
 erlang/apps/sim/src/sim_core.erl   | 13 ++++++++-----
 erlang/apps/sim/src/sim_kernel.erl |  8 ++++++--
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/erlang/apps/sim/src/sim.erl b/erlang/apps/sim/src/sim.erl
index 68b9e6e..4bb07a3 100644
--- a/erlang/apps/sim/src/sim.erl
+++ b/erlang/apps/sim/src/sim.erl
@@ -147,7 +147,10 @@ version() ->
 do_sim(#options{exe = Exe, argv = Argv}) ->
   case sim_loader:load(Exe, Argv, simenv()) of
     {ok, {Mem, PC, SP, Argc, ArgvPtr, Envp}} ->
-      sim_core:run(Mem, PC, SP, Argc, ArgvPtr, Envp);
+      case sim_core:run(Mem, PC, SP, Argc, ArgvPtr, Envp) of
+        {ok, Status} -> halt(Status band 8#377);
+        {error, _Reason} = Error -> Error
+      end;
     {error, _Reason} = Error -> Error
   end.
 
diff --git a/erlang/apps/sim/src/sim_core.erl b/erlang/apps/sim/src/sim_core.erl
index 1e0b051..d7b7ba6 100644
--- a/erlang/apps/sim/src/sim_core.erl
+++ b/erlang/apps/sim/src/sim_core.erl
@@ -26,6 +26,7 @@
 
 -export([ run/6
         , next_pc/2
+        , get_ac/2
         , set_ac/3
         , set_flag/2
         , format_error/1
@@ -40,7 +41,7 @@
           SP :: word(),
           Argc :: word(),
           Argv :: word(),
-          Envp :: word()) -> ok | {error, {module(), term()}}.
+          Envp :: word()) -> {ok, integer()} | {error, {module(), term()}}.
 run(Mem, PC, SP, Argc, Argv, Envp) ->
   PCSection = (PC bsr 18) band ((1 bsl 12) - 1),
   PCOffset = PC band ((1 bsl 18) - 1),
@@ -63,12 +64,14 @@ run(Mem, PC, SP, Argc, Argv, Envp) ->
 %% faults (especially page faults) that may occur at various points, without
 %% creating recursion in the simulator.
 
--spec run(#core{}, sim_mem:mem()) -> {#core{}, sim_mem:mem(), ok | {error, {module(), term()}}}.
+-spec run(#core{}, sim_mem:mem())
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
 run(Core, Mem) ->
   insn_fetch(Core, Mem).
 
 %% Sequential control flow: increment PC but stay in current section.
--spec next_pc(#core{}, sim_mem:mem()) -> {#core{}, sim_mem:mem(), ok | {error, {module(), term()}}}.
+-spec next_pc(#core{}, sim_mem:mem())
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
 next_pc(#core{pc_offset = PCOffset} = Core, Mem) ->
   PCOffset1 = (PCOffset + 1) band ((1 bsl 18) - 1),
   insn_fetch(Core#core{pc_offset = PCOffset1}, Mem).
@@ -212,7 +215,7 @@ global_indirect_word(Core, Mem, IR, MB, I) ->
 %% Instruction Dispatch ========================================================
 
 -spec dispatch(#core{}, sim_mem:mem(), IR :: word(), #ea{})
-      -> {#core{}, sim_mem:mem(), ok | {error, {module(), term()}}}.
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
 dispatch(Core, Mem, IR, EA) ->
   %% Dispatch on the opcode (top 9 bits).
   case IR bsr 4 of
@@ -230,7 +233,7 @@ handle_MOVEI(Core, Mem, IR, #ea{offset = E}) ->
 %% Page Fault Handling =========================================================
 
 -spec page_fault(#core{}, sim_mem:mem(), word(), atom(), term(), fun())
-      -> {#core{}, sim_mem:mem(), ok | {error, {module(), term()}}}.
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
 page_fault(Core, Mem, Address, Op, Reason, Cont) ->
   %% This should trap to kernel mode, but for now we treat all faults as fatal.
   PC = (Core#core.pc_section bsl 18) bor Core#core.pc_offset,
diff --git a/erlang/apps/sim/src/sim_kernel.erl b/erlang/apps/sim/src/sim_kernel.erl
index 8f86a58..569a845 100644
--- a/erlang/apps/sim/src/sim_kernel.erl
+++ b/erlang/apps/sim/src/sim_kernel.erl
@@ -41,12 +41,16 @@
 %% are from Linux' <asm-generic/errno.h>.
 
 -spec handle_JSYS(#core{}, sim_mem:mem(), IR :: word(), #ea{})
-      -> {#core{}, sim_mem:mem(), ok | {error, {module(), term()}}}.
-handle_JSYS(Core, Mem, _IR, #ea{offset = Nr} = _EA) ->
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_JSYS(Core, Mem, _IR, #ea{offset = Nr}) ->
   case Nr of
+    94 -> handle_exit_group(Core, Mem);
     _ -> return_errno(Core, Mem, ?ENOSYS)
   end.
 
+handle_exit_group(Core, Mem) ->
+  {Core, Mem, {ok, sim_core:get_ac(Core, 1)}}.
+
 return_errno(Core0, Mem, Errno) ->
   Core1 = sim_core:set_ac(Core0, 1, Errno),
   Core2 = sim_core:set_flag(Core1, ?PDP10_PF_OVERFLOW),