Include some rather simple CMAKE_TOOLCHAIN_FILE.

- Update the build.sh and fix some typos.
  + Don't add the OSX ones because I have not tested them and it won't
    even build anyway due to the libaio dependency. Needs to use POSIX AIO
    or something else.
- They are rather simple and all the magic happens in two lines.
  + First line tells cmake to get ready to compile FOR linux or darwin.
    It also sets CMAKE_CROSSCOMPILING to true which is the only way to
    let cmake known that we are using stuff not from the host.
  + CMAKE_C_COMPILER/CMAKE_CXX_COMPILER are basically used to detect
    the architecture of the target. Since I used generic cc/c++ the
    hardcoded -m32 is needed to ensure we get TARGET=i386. Also
    since I hardcode -m32 and use c++/cc it's to be noted that
    we can only do i386->i386 (trivial), amd64 -> i386, and x32->i386.
    .
    Using something like i586-linux-gnu-{gcc,g++} would also work and
    enable arm -> i386, etc but it's infeasible and impractical to do all
    the combinations. File is simple enough that a distro or user can
    create their own and cross compiling is rather tedious compared
    to using a chroot to compile it.
- I tested it in Debian with "dpkg-buildpackage -ai386" but installing the
  build dependencies was rather tedious.

build.sh

@@ -42,6 +42,7 @@ for ARG in "$@"; do
         --wx28        ) flags+=(-DWX28_API=TRUE) ;;
         --gtk3        ) flags+=(-DGTK3_API=TRUE) ;;
         --no-simd     ) flags+=(-DDISABLE_ADVANCE_SIMD=TRUE) ;;
+        --cross-multilib ) flags+=(-DCMAKE_TOOLCHAIN_FILE=cmake/linux-compiler-i386-multilib.cmake) ;;
         -D*           ) flags+=($ARG) ;;
 
         *)
@@ -54,17 +55,18 @@ for ARG in "$@"; do
             echo "--clean         : Do a clean build."
             echo "--extra         : Build all plugins"
             echo
-            echo "** Developper option **"
+            echo "** Developer option **"
             echo "--clang         : Build with Clang/llvm"
             echo "--asan          : Enable Address sanitizer"
             echo
             echo "--wx28          : Force wxWidget 2.8"
             echo "--glsl          : Replace CG backend of ZZogl by GLSL"
             echo "--egl           : Replace GLX by EGL (ZZogl plugins only)"
-            echo "--sdl2          : Build with SDL2 (crash if wx is linked to SDL1)"
+            echo "--sdl2          : Build with SDL2 (crashes if wx is linked to SDL1.2)"
             echo "--gles          : Replace openGL backend of GSdx by openGLES3.1"
+            echo "--cross-multilib: Build a 32bit PCSX2 on a 64bit machine using multilib."
             echo
-            echo "** Hardcode Developper option **"
+            echo "** Hardcode Developer option **"
             echo "--no-simd       : Only allow sse2"
             echo "--gtk3          : replace GTK2 by GTK3"
             exit 1

cmake/darwin-compiler-i386-clang.cmake

@@ -0,0 +1,20 @@
+# Tell cmake we are cross compiling and targeting darwin
+set(CMAKE_SYSTEM_NAME Darwin)
+set(CMAKE_SYSTEM_PROCESSOR i686)
+
+# Use clang and target i686-apple-darwin.
+set(CMAKE_C_COMPILER clang -m32)
+set(CMAKE_C_COMPILER_TARGET i686-apple-darwin)
+set(CMAKE_CXX_COMPILER clang++ -m32)
+set(CMAKE_CXX_COMPILER_TARGET i686-apple-darwin)
+
+# Enable clang
+set(USE_CLANG TRUE)
+
+# If given a CMAKE_FIND_ROOT_PATH then
+# FIND_PROGRAM ignores CMAKE_FIND_ROOT_PATH (probably can't run)
+# FIND_{LIBRARY,INCLUDE,PACKAGE} only uses the files in CMAKE_FIND_ROOT_PATH.
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

cmake/darwin-compiler-i386-generic.cmake

@@ -0,0 +1,15 @@
+# Tell cmake we are cross compiling and targeting darwin
+set(CMAKE_SYSTEM_NAME Darwin)
+set(CMAKE_SYSTEM_PROCESSOR i686)
+
+# Leave it generic since it could be clang, gnu, etc.
+set(CMAKE_C_COMPILER cc -m32)
+set(CMAKE_CXX_COMPILER c++ -m32)
+
+# If given a CMAKE_FIND_ROOT_PATH then
+# FIND_PROGRAM ignores CMAKE_FIND_ROOT_PATH (probably can't run)
+# FIND_{LIBRARY,INCLUDE,PACKAGE} only uses the files in CMAKE_FIND_ROOT_PATH.
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

cmake/linux-compiler-i386-multilib.cmake

@@ -0,0 +1,16 @@
+# Tell cmake we are cross compiling and targeting linux
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR i686)
+
+# It could be i?86-*linux-gnu, x86_64-*linux-gnu, x86_64-*linux-gnux32, etc.
+# Leave it generic to only support amd64 or x32 to i386 with any compiler.
+set(CMAKE_C_COMPILER cc -m32)
+set(CMAKE_CXX_COMPILER c++ -m32)
+
+# If given a CMAKE_FIND_ROOT_PATH then
+# FIND_PROGRAM ignores CMAKE_FIND_ROOT_PATH (probably can't run)
+# FIND_{LIBRARY,INCLUDE,PACKAGE} only uses the files in CMAKE_FIND_ROOT_PATH.
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)