Install El Capitan with VirtualBox on OS X

I am creating an El Capitan Virtual Box on my Mac. This is the process I take. I pressed some keys (it says any) as shown in second image, but I get nowhere. What should I do to move from here?

1. I double click the "El Capitan" option

   

2. This is the screen that opens next.

   

3. This is how I specified the elcap.dmg. This is the dmg file of Install OS X El Capitan.app

   

Nothing is happening. What am I doing wrong?

The dmg file (Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg) is no bootable image.

To create a bootable file use the following script. You may have to modify some paths (i.e. the user name in the last line and the path to Install OS X El Capitan.app (and the inner InstallESD.dmg file) in the 6th line):

#!/bin/bash  

# Create bootable El Capitan ISO

# Mount the installer image  
hdiutil attach "/Applications/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg" -noverify -nobrowse -mountpoint /Volumes/esd

# Create empty cdr image  
hdiutil create -o ElCapitan.cdr -size 8000m -layout SPUD -fs HFS+J

# Mount the cdr image  
hdiutil attach ElCapitan.cdr.dmg -noverify -nobrowse -mountpoint /Volumes/iso

# Restore Base System to the cdr image 
asr restore -source /Volumes/esd/BaseSystem.dmg -target /Volumes/iso -noprompt -noverify -erase

# Remove Package link and replace with actual files  
rm /Volumes/OS\ X\ Base\ System/System/Installation/Packages

# Copy Base System  
cp -rp /Volumes/esd/Packages /Volumes/OS\ X\ Base\ System/System/Installation
cp -rp /Volumes/esd/BaseSystem.chunklist /Volumes/OS\ X\ Base\ System/
cp -rp /Volumes/esd/BaseSystem.dmg /Volumes/OS\ X\ Base\ System/

# Unmount the installer image  
hdiutil detach /Volumes/esd

# Unmount the cdr image  
hdiutil detach /Volumes/OS\ X\ Base\ System

# Convert the cdr to ISO/CD master 
hdiutil convert ElCapitan.cdr.dmg -format UDTO -o ElCapitan.iso

# Rename the ISO and move it to the desktop  
mv ElCapitan.iso.cdr $HOME/Desktop/ElCapitan.iso

# Clean up temporary file
rm ElCapitan.cdr.dmg

Paste the content in a text editor to a new document as plain text and save it as prepare_elcapitan_cdr.sh on your desktop.

Open Terminal, chmod the script and execute it:

chmod +x ~/Desktop/prepare_elcapitan_cdr.sh
cd ~/Desktop
./prepare_elcapitan_cdr.sh

Detach elcap.dmg from the VM. Use the final ElCapitan.iso as installer iso and attach it to the virtual SATA Port 1. You can delete the ElCapitan.cdr.dmg file.

I tested klanomoath's accepted answer to this question using a Mac mini (2018) running macOS Catalina Version 10.15.4. I needed to make the following changes.

• I downloaded InstallMacOSX.dmg from the Apple website How to upgrade to OS X El Capitan. The file was placed in my Downloads folder. After downloading, the file needs to be opened with the Finder Application.

• The first command in klanomoath's answer is given below.

  # Create bootable El Capitan ISO
  
  # Mount the installer image  
  hdiutil attach "/Applications/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg" -noverify -nobrowse -mountpoint /Volumes/esd
  

   
  This above command needs to be replaced with the commands given below. A temporary folder named El Capitan will be created in your Downloads folder.

  # Create bootable El Capitan ISO
  
  # Extract the files from the downloaded file
  hdiutil attach "$HOME"/Downloads/InstallMacOSX.dmg
  rm -rf /tmp/El\ Capitan
  pkgutil --expand /Volumes/Install\ OS\ X/InstallMacOSX.pkg /tmp/El\ Capitan
  diskutil eject Install\ OS\ X
  cd /tmp/El\ Capitan
  
  # Mount the installer image  
  hdiutil attach InstallMacOSX.pkg/InstallESD.dmg  -noverify -nobrowse -mountpoint /Volumes/esd
  

   

• The last two commands in klanomoath's answer are given below.

  # Rename the ISO and move it to the desktop  
  mv ElCapitan.iso.cdr $HOME/Desktop/ElCapitan.iso
  
  # Clean up temporary file
  rm ElCapitan.cdr.dmg
  

   
  These above commands need to be replaced with the commands given below.

  # Rename the ISO and move it to the Downloads folder  
  mv ElCapitan.iso.cdr "$HOME"/Downloads/ElCapitan.iso
  
  # Clean up temporary folder
  cd "$HOME"
  rm -r /tmp/El\ Capitan
  

   

• When executing the command, you may an error message similar to the one given below. The question System hangs when creating bootable disk drive addresses this error.

  asr: Couldn't personalize volume /Volumes/OS X Base System
  

   

• I needed to enter the following command before starting the the virtual machine named El Capitan.

  Note: I needed to enter these commands, because El Capitan can not be installed on a 2018 Mac mini. If El Capitan can be installed on your Mac, then you probably do not need to enter these commands.

  VBoxManage setextradata "El Capitan" "VBoxInternal/Devices/efi/0/Config/DmiSystemProduct" "Macmini6,2"
  VBoxManage setextradata "El Capitan" "VBoxInternal/Devices/efi/0/Config/DmiSystemVersion" "1.0"
  VBoxManage setextradata "El Capitan" "VBoxInternal/Devices/efi/0/Config/DmiBoardProduct" "Mac-F65AE981FFA204ED"
  VBoxManage setextradata "El Capitan" "VBoxInternal/Devices/smc/0/Config/DeviceKey" "ourhardworkbythesewordsguardedpleasedontsteal(c)AppleComputerInc"
  VBoxManage setextradata "El Capitan" "VBoxInternal/Devices/smc/0/Config/GetKeyFromRealSMC" 1
  VBoxManage modifyvm "El Capitan" --cpuidset 00000001 000106e5 06100800 0098e3fd bfebfbff
  

   

References

forums.virtualbox.org