unix: drop the 32bit build

Makefile

@@ -13,11 +13,7 @@ FIRMWARE_BUILD_DIR    = $(BUILD_DIR)/firmware
 UNIX_BUILD_DIR        = $(BUILD_DIR)/unix
 
 UNAME_S := $(shell uname -s)
-ifeq ($(UNAME_S),Darwin)
-UNIX_PORT_OPTS ?= TREZOR_X86=0
-else
-UNIX_PORT_OPTS ?= TREZOR_X86=1
-endif
+UNIX_PORT_OPTS ?=
 CROSS_PORT_OPTS ?=
 
 ifeq ($(DISPLAY_ILI9341V), 1)

SConscript.unix

@@ -274,11 +274,6 @@ env.Replace(
     MPY_TOOL='$PYTHON vendor/micropython/tools/mpy-tool.py',
     MPY_CROSS='vendor/micropython/mpy-cross/mpy-cross', )
 
-if int(ARGUMENTS.get('TREZOR_X86', '0')):
-    env.Append(
-        CCFLAGS='-m32',
-        LINKFLAGS='-m32', )
-
 #
 # Micropython version
 #

docs/build.md

@@ -18,21 +18,20 @@ make vendor
 Install the required packages, depending on your operating system.
 * __Debian/Ubuntu__:
   ```sh
-  sudo dpkg --add-architecture i386
   sudo apt-get update
-  sudo apt-get install scons libsdl2-dev:i386 libsdl2-image-dev:i386 gcc-multilib
+  sudo apt-get install scons libsdl2-dev libsdl2-image-dev
   ```
 * __Fedora__:
   ```sh
-  sudo yum install scons SDL2-devel.i686 SDL2_image-devel.i686
+  sudo yum install scons SDL2-devel SDL2_image-devel
   ```
 * __OpenSUSE__:
   ```sh
-  sudo zypper install scons libSDL2-devel-32bit libSDL2_image-devel-32bit
+  sudo zypper install scons libSDL2-devel libSDL2_image-devel
   ```
 * __Arch__:
   ```sh
-  sudo pacman -S gcc-multilib scons lib32-sdl2 lib32-sdl2_image
+  sudo pacman -S scons sdl2 sdl2_image
   ```
 * __Mac OS X__:
   ```sh