Below [1] is a script to cross-compile OpenSSL & OTP for aarch64-darwin.

A couple of notes however:

1. Wx cannot be cross-compiled yet:

   > ```
   > *********************************************************************
   > *********************************************************************
   > **********************  APPLICATIONS INFORMATION  *******************
   > *********************************************************************
   >
   > wx             : Cross compilation of the wx driver is not supported yet, wx will NOT be usable
   > ```

2. Erlang shell successfully starts:

       $ uname -sm
       Darwin arm64
       $ ./bin/erl
       Erlang/OTP 24 [erts-12.1.5] [source-df1294f108] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1]

       Eshell V12.1.5  (abort with ^G)
       1>

3. But crypto is not working yet:

       ./bin/erl
       Erlang/OTP 24 [erts-12.1.5] [source-df1294f108] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1]

       Eshell V12.1.5  (abort with ^G)
       1> crypto:start().
       =ERROR REPORT==== 29-Nov-2021::14:50:14.218776 ===
       Unable to load crypto library. Failed with error:
       "load_failed, Failed to load NIF library: 'dlopen(/Users/wojtek/Downloads/otp-24.1.7-aarch64-darwin/lib/crypto-5.0.4/priv/lib/crypto.so, 2): no suitable image found.  Did find:
               /Users/wojtek/Downloads/otp-24.1.7-aarch64-darwin/lib/crypto-5.0.4/priv/lib/crypto.so: mach-o, but wrong filetype
               /Users/wojtek/Downloads/otp-24.1.7-aarch64-darwin/lib/crypto-5.0.4/priv/lib/crypto.so: stat() failed with errno=35'"
       OpenSSL might not be installed on this system.

       =WARNING REPORT==== 29-Nov-2021::14:50:14.222040 ===
       The on_load function for module crypto returned:
       {error,{load_failed,"Failed to load NIF library: 'dlopen(/Users/wojtek/Downloads/otp-24.1.7-aarch64-darwin/lib/crypto-5.0.4/priv/lib/crypto.so, 2): no suitable image found.  Did find:\n\t/Users/wojtek/Downloads/otp-24.1.7-aarch64-darwin/lib/crypto-5.0.4/priv/lib/crypto.so: mach-o, but wrong filetype\n\t/Users/wojtek/Downloads/otp-24.1.7-aarch64-darwin/lib/crypto-5.0.4/priv/lib/crypto.so: stat() failed with errno=35'"}}

       ** exception error: undefined function crypto:start/0

[1] the script:

```
set -e

main() {
  export MAKEFLAGS=-j$(getconf _NPROCESSORS_ONLN)

  openssl_vsn=1.1.1l
  otp_vsn=$(cat OTP_VERSION)
  target=aarch64-darwin

  openssl_dir="$PWD/tmp/openssl-$openssl_vsn-$target"
  otp_dir="$PWD/tmp/otp-$otp_vsn-$target"

  mkdir -p tmp

  if [ ! -d "$openssl_dir" ]; then
    build_openssl $openssl_dir $openssl_vsn $target
  fi

  export PATH=$openssl_dir/bin:$PATH
  echo "openssl"
  file `which openssl`
  echo

  if [ ! -d $otp_dir ]; then
    build_otp $otp_dir $otp_vsn $target $openssl_dir
  fi

  (cd $otp_dir && ./Install -sasl $PWD)
  export PATH=$otp_dir/bin:$PATH
  echo "otp"
  file `which erlc`
  file $otp_dir/lib/crypto-*/priv/lib/crypto.so
  # erl +V
  # erl -noshell -eval 'ok = crypto:start(), io:format("crypto ok~n"), halt().'
  echo
}

build_openssl() {
  dir=$1
  vsn=$2
  target=$3

  if [ "$target" = "x86_64-darwin" ]; then
    openssl_target=darwin64-x86_64-cc
  fi
  if [ "$target" = "aarch64-darwin" ]; then
    openssl_target=darwin64-arm64-cc
  fi

  cd tmp

  if [ ! -d openssl-$vsn-src ]; then
    url=https://www.openssl.org/source/openssl-$vsn.tar.gz
      echo "downloading $url"
    curl --fail -LO $url
    tar -xf openssl-$vsn.tar.gz
    mv openssl-$vsn openssl-$vsn-src
  fi

  cd openssl-$vsn-src
  ./Configure \
    $openssl_target \
    --prefix=$dir
  make
  make install_sw
  cd ../..
}

build_otp() {
  dir=$1
  vsn=$2
  target=$3
  openssl_dir=$4
  cwd=$PWD

  # path to OTP git checkout. Comment-out if you want to download it.
  otp_src_dir=$HOME/src/otp

  if [ ! -d "$otp_src_dir" ]; then
    cd tmp
    url="https://github.com/erlang/otp/releases/download/OTP-${vsn}/otp_src_${vsn}.tar.gz"
    echo "downloading $url"
    curl --fail -LO $url
    tar -xf otp_src_${vsn}.tar.gz
    cd otp_src_${vsn}
  fi

  export ERL_TOP=`pwd`

  ./otp_build configure \
    --disable-dynamic-ssl-lib \
    --with-ssl=$openssl_dir \
    --xcomp-conf=xcomp/erl-xcomp-$target.conf

  ./otp_build boot -a
  ./otp_build release -a $dir
  cd $cwd
}

main
```