MFC r303818, r303833, r303941, r304478, r304481, r304483, r304484, r304554,

    r304555, r304556, r304557, r304558, r304559, r304561, r304563, r304564,
    r304565, r304615, r304742, r304743, r304744, r304745, r304748, r304886,
    r304991, r305928, r305938, r305987, r306185:

  Bring CloudABI support back in sync with HEAD.

  - Add support for running 32-bit executables on amd64, armv6 and i386.

  - As these new architectures require the use of the vDSO, merge back
    vDSO support for 64-bit executables running on amd64 and arm64 as
    well. This has the advantage that support for vDSO-less execution
    can be phased out when 11.0 becomes unsupported, as opposed to 11.x.

  This change has been tested by running the cloudlibc unit tests on all
  supported architectures, which seems to work fine.

1 files changed, 29 insertions, 11 deletions

diff --git a/share/man/man4/cloudabi.4 b/share/man/man4/cloudabi.4
index e7a5653..a387c77 100644
--- a/share/man/man4/cloudabi.4
+++ b/share/man/man4/cloudabi.4
@@ -1,4 +1,4 @@
-.\" Copyright (c) 2015 Nuxi, https://nuxi.nl/
+.\" Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
@@ -22,17 +22,25 @@
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
-.Dd October 22, 2015
+.Dd September 22, 2016
 .Dt CLOUDABI 4
 .Os
 .Sh NAME
 .Nm cloudabi ,
+.Nm cloudabi32 ,
 .Nm cloudabi64
 .Nd CloudABI support
 .Sh SYNOPSIS
-Support for 64-bit CloudABI executables can be compiled into the kernel
+Support for 32-bit CloudABI executables can be compiled into the kernel
 by adding this line to the kernel configuration file:
 .Bd -ragged -offset indent
+.Cd "options COMPAT_CLOUDABI32"
+.Ed
+.Pp
+Similarly,
+support for 64-bit CloudABI executables can be enabled by adding this
+line:
+.Bd -ragged -offset indent
 .Cd "options COMPAT_CLOUDABI64"
 .Ed
 .Pp
@@ -40,6 +48,7 @@ CloudABI support can also be loaded at boot time from
 .Xr loader.conf 5 :
 .Bd -literal -offset indent
 cloudabi_load="YES"
+cloudabi32_load="YES"
 cloudabi64_load="YES"
 .Ed
 .Sh DESCRIPTION
@@ -52,19 +61,21 @@ and hardened against security exploits.
 .Pp
 Support for CloudABI on
 .Fx
-consists of two separate kernel modules.
+consists of three separate kernel modules.
 The
 .Nm cloudabi
 kernel module implements all of the system calls that do not depend on
-data structures that differ between architectures.
+data structures that differ between hardware architectures.
 .Pp
 The
+.Nm cloudabi32
+and
 .Nm cloudabi64
-kernel module provides implementations of all of the machine-dependent
-system calls.
-It assumes that pointers stored in data structures provided as system
-call arguments are 64 bits in size.
-It also provides the image activator that loads and starts 64-bit ELF
+kernel modules provide implementations of all of the machine-dependent
+system calls,
+assuming that pointers stored in data structures are either 32 bits or
+64 bits in size.
+These modules also provide the image activators that load and start ELF
 executables.
 .Pp
 Though the
@@ -72,8 +83,12 @@ Though the
 module can be loaded on any architecture supported by
 .Fx ,
 the
+.Nm cloudabi32
+module is only available on amd64, armv6 and i386.
+The same holds for the
 .Nm cloudabi64
-module is only available for amd64 and arm64.
+module,
+which is only available for amd64 and arm64.
 .Pp
 A full cross compilation toolchain for CloudABI is available in the
 .Pa devel/cloudabi-toolchain
@@ -93,6 +108,9 @@ restricted set of resources.
 .Xr linux 4 ,
 .Xr elf 5
 .Pp
+CloudABI for FreeBSD:
+.Pa https://nuxi.nl/cloudabi/freebsd/ .
+.Pp
 cloudlibc on GitHub:
 .Pa https://github.com/NuxiNL/cloudlibc .
 .Pp