Bringing back 32-bit apps to life

I have found out that 32-bit apps support in Catalina was disabled but not completely removed

Current state is enough to run some console 32-bit apps in catalina

to have it run this command:

sudo nvram boot-args=”no32exec=0″

if one wants more, like gui app, need to use some libs from mojave probably.

next is some output from console

$ uname -a

Darwin Macs-Mac-Pro.local 19.0.0 Darwin Kernel Version 19.0.0: Wed Sep 25 20:18:50 PDT 2019; root:xnu-6153.11.26~2/RELEASE_X86_64 x86_64

$ file EfiDecompress.macosx

EfiDecompress.macosx: Mach-O executable i386

$ ./EfiDecompress.macosx

EfiDecompress v1.1 -Efi File Decompress Utility

Copyright (c) 2005-2006 Intel Corporation. All rights reserved.

Usage: EfiDecompress Inputfile Outputfile

$ otool -L EfiDecompress.macosx


/usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)

/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.3)

$ file /usr/lib/libSystem.B.dylib

/usr/lib/libSystem.B.dylib: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit dynamically linked shared library x86_64] [i386:Mach-O dynamically linked shared library i386]

/usr/lib/libSystem.B.dylib (for architecture x86_64): Mach-O 64-bit dynamically linked shared library x86_64

/usr/lib/libSystem.B.dylib (for architecture i386): Mach-O dynamically linked shared library i386

$ nvram boot-args

boot-args no32exec=0


here is how one can try to run 32-bit gui app, can’t say it’s working very well

DYLD_ROOT_PATH=/Volumes/Macintosh\ SSD/ ./CrossOver


DYLD_ROOT_PATH should specify root volume for macos mojave


  1. October 16th, 2019 | 5:50 pm

    […] vous avez encore besoin de pouvoir excécuter du code 32 bit sous Catalina, il est possible de réactiver la compatibilité (limitée) par ligne de commande […]

  2. December 16th, 2019 | 9:48 am

    […] work on this version and they will have to settle at best for the Mojave in the future. But as was discovered Netkas, support for 32-bit is not totally removed from macOS Catalina, she is rather turned […]

  3. December 16th, 2019 | 10:06 am

    […] en esta versión y que tendrá que conformarse, en el mejor de Mojave en el futuro. Pero como fue descubierto Netkas, soporte para 32-bit no está totalmente eliminado de macOS Catalina, ella es más bien […]

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