A program for installing macOS without using an installation flash drive.

[Sergey_Galan]

4 minutes ago, jlrycm said:

@Sergey_Galan when you say that SIP must be disabled to install in a separate volume, can I install it if the SIP defined for that separate volume is <01000000>? Is there data loss when choosing to install in a separate volume?

You can restore the system to a separate disk (i.e. save the data), you can install a clean system on a formatted apfs partition. This works with SIP 67080000, I haven't checked what exactly needs to be disabled in SIP yet.

[jlrycm]

7 minutes ago, Sergey_Galan said:

You can restore the system to a separate disk (i.e. save the data), you can install a clean system on a formatted apfs partition. This works with SIP 67080000, I haven't checked what exactly needs to be disabled in SIP yet.

@Sergey_Galan Thanks. I was planning to test your app which sounds amazing but wanted to confirm first the level of SIP to be disabled. I’m using an universal EFI that loads both Sequoia and Tahoe where SIP is defined as 01000000 and would test reinstalling Tahoe in the SATA SSD that I’m using for testing.

Edited July 20, 2025 by jlrycm

[Sergey_Galan]

Updated the topic title with screenshots and a new revision. I think it's a working option. Avoid the red ones if you don't understand what awaits you. I mean the "Install macOS on system volume" option.

[LockDown]

Progress now working! 

Thanks @Sergey_Galan

[Mirone]

@Sergey_Galan I tested the app the first time, it restarted before finishing the process, and when I tried to boot from the installed disk, the system didn't start. On the second attempt, though, it worked well. What bothered me was having to type my password in a 'Secure Text Field'. Either way, thanks for the good work on the app!

[Sergey_Galan]

13 hours ago, Mirone said:

@Sergey_Galan I tested the app the first time, it restarted before finishing the process, and when I tried to boot from the installed disk, the system didn't start. On the second attempt, though, it worked well.

As soon as you click the "Install" button, control is transferred to the startosinstall utility, perhaps it crashed, I slightly increased the time before rebooting using the "--rebootdelay 10" option, I hope this will not happen again.

The password is written and stored in the keychain, delivered to the script by reading from the keychain:

passwordIncorrect()
{
echo "STOP! Incorrect password!"
exit 1
}

password()
{
passMacInstal=Mac-$(ioreg -rd1 -c IOPlatformExpertDevice | awk '/IOPlatformUUID/' | cut -f2 -d"=" | tr -d '" ' | rev | cut -f4-5 -d '-' | tr -d -)
/usr/bin/security find-generic-password -wl ${passMacInstal} 2>/dev/null
}

#Verifying root from Administrator.
password | sudo -S >/dev/null 2>&1 echo "" || passwordIncorrect
sudo -S "$1"/Contents/Resources/startosinstall --volume /Volumes/"$2" --agreetolicense --nointeraction --rebootdelay 10

The ${passMacInstal} variable is the unique login created.

For now this is it, in the future I might change something))

I updated the version, I hope the startosinstall utility won't let me down again)))

Edited July 21, 2025 by Sergey_Galan

[Sergey_Galan]

17 hours ago, Mirone said:

@Sergey_Galan I tested the app the first time, it restarted before finishing the process, and when I tried to boot from the installed disk, the system didn't start. On the second attempt, though, it worked well. What bothered me was having to type my password in a 'Secure Text Field'. Either way, thanks for the good work on the app!

I did it like this 

 

 

Made an update to the topic.

[Mirone]

As it should be, good job!

[LockDown]

Hi @Sergey_Galan

Why not popup an error message if SIP is enabled instead of the progress bar goes to 100% (doesnt make sense) in a matter or 2-3sec then says nothing untill you check the log.

You can even alert it once the app is launched

Edited August 8, 2025 by LockDown

[Sergey_Galan]

11 minutes ago, LockDown said:

Hi @Sergey_Galan

Why not popup an error message if SIP is enabled instead of the progress bar goes to 100% (doesnt make sense) in a matter or 2-3sec then says nothing untill you check the log.

You can even alert it once the app is launched

Installing the system on another partition goes through a check. If SIP is enabled, the process will not start. For original Mac computers this is enough, for Hackintosh it is necessary to investigate which positions must be "disabled"
I don't want to do this yet, to be honest))) This program is not so popular)))

[Sergey_Galan]

On 8/8/2025 at 4:50 PM, LockDown said:

Hi @Sergey_Galan

Why not popup an error message if SIP is enabled instead of the progress bar goes to 100% (doesnt make sense) in a matter or 2-3sec then says nothing untill you check the log.

You can even alert it once the app is launched

I think this will make it clear.

 

[Anto65]

Just completed a clean install and configuration of 26 B9, on the same disk , already made an RDR image  😛
Successfully executed with MacOS Install.app v1.0.3  
v1.0.8 still doesn't work here. 🤷‍♂️

 

Spoiler

 

Edited September 3, 2025 by Anto65

[jm26200]

hi  all  

 

I wanted to test ur tool and everything went well until the end but unfortunately without EFI partition !!

 

🤔

[jm26200]

Thanks, my friend @eSaF

Yes, I know this EFI partition is mandatory, but isn't the tool from Sir Sery_Galand's developer capable of doing it?
Because in the end, there's a reboot, but no EFI partition on the external SSD.

 

regards

Edited September 8, 2025 by jm26200

[LockDown]

54 minutes ago, jm26200 said:

Because in the end, there's a reboot, but no EFI partition on the external SSD.

 

regards

its for real macs

[Sergey_Galan]

On 9/3/2025 at 2:42 PM, Anto65 said:

Just completed a clean install and configuration of 26 B9, on the same disk , already made an RDR image  😛
Successfully executed with MacOS Install.app v1.0.3  
v1.0.8 still doesn't work here. 🤷‍♂️

 

  Reveal hidden contents

 

Oh yeah, thanks for finding this out.
v1.0.9 I changed it a little:
 

"Install macOS" mode
It is possible to install/update macOS on the system or on a prepared partition in APFS format. To install macOS, you must disable SIP.

 

"Clean install of macOS on system volume" mode
Installing macOS on the system volume will destroy all your data.
It is not necessary to disable SIP.

 

     

 

 

Edited November 14, 2025 by Sergey_Galan

[Anto65]

 

 

1.0.8 wouldn't even start, but this one works great with a clean install on both , the system drive (I'm writing from there) and another disk.
If I may, I'd add a "refresh" button/option for scanning disks... Thanks.

 

Spoiler

       

 

     

 

[Sergey_Galan]

15 minutes ago, Anto65 said:

If I may, I'd add a "refresh" button/option for scanning disks... Thanks.

After the first click on the button with disks, the list is updated, with the second click we see the updated list.
But if you feel discomfort and need for a refresh button, it is not difficult to make.
I will do it in the next issue. 🔄

[Anto65]

OK, since I had already opened the app and then prepared the disk, when I clicked on the disks button the new ones did not appear... I did not try with the second click... if it works then it is not necessary 👍

 

... I'm trying the "Update" option now. 🙂 ... Fine 

Edited September 8, 2025 by Anto65

[Sergey_Galan]

MacOS Install-v1.1.0 (added to the title)

Changes:
When starting, the program searches for the Mac OS installer in the programs folder. The program is sensitive only to the Mac OS installer.
And other fixes.

[Anto65]

Great!

When the app finished downloading the installer to the disk, It couldn't restart because I had another app open.
I thought I had to start over, but instead I restarted and the macOS installer was present in the GUI... the installation started.
There might be a way to prevent it from restarting once it's finished by keeping another app open.

 

Edit : 

 

Hmmm, I think there's a problem , it installing on the current disk (Thaoe) and not the one I selected (Tahoe-26).

When selecting the disk, even if I select Tahoe-26, it always returns to Tahoe, which is the disk where the OS is installed.

 

Works great on MacOS Install-1.0.9

 

Spoiler

 

https://limewire.com/d/WSGY4#ydff2krh80

 

Edited September 12, 2025 by Anto65

[Sergey_Galan]

On 9/12/2025 at 12:21 PM, Anto65 said:

 

Hmmm, I think there's a problem , it installing on the current disk (Thaoe) and not the one I selected (Tahoe-26).

When selecting the disk, even if I select Tahoe-26, it always returns to Tahoe, which is the disk where the OS is installed.

Thanks, I fixed it.

MacOS Install-v1.1.1.zip

[Anto65]

First Post 😉

[Anto65]

4 hours ago, Sergey_Galan said:

Thanks, I fixed it.

MacOS Install-v1.1.1.zip

 

Everything is ok with this version 👍

[PippoX0]

Nice tool