From 81b46c478107687c427bacf91f67995d697b3571 Mon Sep 17 00:00:00 2001 From: Mikael Pettersson Date: Fri, 10 Jul 2020 21:51:17 +0200 Subject: [PATCH] sim: sim_kernel: add FIXME about improved syscall return convention --- erlang/apps/sim/src/sim_kernel.erl | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/erlang/apps/sim/src/sim_kernel.erl b/erlang/apps/sim/src/sim_kernel.erl index 569a845..ac54807 100644 --- a/erlang/apps/sim/src/sim_kernel.erl +++ b/erlang/apps/sim/src/sim_kernel.erl @@ -37,6 +37,10 @@ %% bits of EA, and the parameters in AC1 to AC7. %% A successful call clears the Overflow flag and returns a value in AC1. %% A failed call sets the Overflow flag and returns an error code in AC1. +%% [FIXME: Change to return success as 0 in AC0 and a value in AC1, and failure +%% as a non-zero errno in AC0 and -1 in AC1. A more common approach on Linux +%% is to signal failure by returning -errno, detectable by being >= -4095U, but +%% implementing that comparison on the PDP10 is fairly expensive.] %% System call numbers are from Linux' , and error codes %% are from Linux' .