Mac BootROM manual update

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • reformatt
    Badcaps Legend
    • Feb 2020
    • 1398
    • Australia

    #1

    Mac BootROM manual update

    So following on from this thread, I've been meaning to work out a way to update these boards manually without either having to pull the PROM or doing a reinstall of MAC OS. If I'm just fixing a board, I should be able to just update like you do on a PC laptop right? Well this is an Apple product......

    Firmware is well hidden in the installer. But once you've found it, you can just dump it on a memory stick or a spare SSD with Big Sur installed. Many thanks to StarterGo on GitHub for the pointers. I've done this for Macbook Air 820-3437 and 820-00165 boards, but other non T2 machines could be done similarly using the right firmware file.

    1. Download MAC OS installer via Terminal (firmware for 2013/14, and 2015/17 models are in this installer)

    softwareupdate --fetch-full-installer --full-installer-version 11.7.4

    Alternately, you can use Core Legacy Patcher GUI to download the installer.
    https://github.com/dortania/Opencore...tcher/releases

    2. From Applications folder, hold Control and select Install Mac OS Big Sur, Open Package Contents.

    3. Open Contents/SharedSupport/SharedSupport.dmg.

    4. Open SharedSupport from Desktop

    5. Open com_apple_MobileAsset_MacSoftware_Update

    6. Locate zip file in this folder and open it (will be long file name like cd4506......5C26.zip, should be around 11.5GB in size).

    7. Firmware located under AssetData/boot/EFI/EFIPayloads. Filename corresponds to each model

    MBA61.scap Macbook Air 2013/14 (820-3437)
    MBA71.fd Macbook Air 2015/17 (820-00165)

    8. Drag firmware file required to Desktop while holding Option key (copy)

    9. Check SIP status via Terminal
    csrutil status

    If enabled, you must reboot to Recovery Mode to disable, either CMD+R or external USB.

    10. Disable SIP. From Terminal, enter
    csrutil -disable

    11. Reboot back to MAC OS.

    12. From Terminal enter
    820-3437 boards:
    sudo /usr/sbin/bless -firmware ~/Desktop/MBA61.scap --verbose --recovery

    820-00165
    sudo /usr/sbin/bless -firmware ~/Desktop/MBA71.fd --verbose --recovery

    Enter password when prompted.

    13.Shut down the MAC i.e. power off (do not select reboot).

    14. Power on system, firmware update should complete and reboot.

    15. In MAC OS, confirm firmware has been updated.
    474.0.0.0 for 820-3437
    476.0.0.0 for 820-00165

    16. Reboot to recovery console, re-enable SIP via Terminal
    csrutil enable
  • alassane.dontavius
    Banned
    • Jan 2023
    • 28
    • USA

    #2
    Re: Mac BootROM manual update

    btw u can update T2 bridgeOS same way, if you have T2 on very old version of bridgeOS you can update to 7.2 offline instead of the latest bridgeos 7.4

    Comment

    • dellxps15
      Badcaps Legend
      • Feb 2014
      • 1585
      • italy

      #3
      Re: Mac BootROM manual update

      tnx man, tried it today and worked like charm

      Comment

      • reformatt
        Badcaps Legend
        • Feb 2020
        • 1398
        • Australia

        #4
        Re: Mac BootROM manual update

        Addendum to this guide. Very old BIOS versions don't recognize APFS formatted drives, hence Big Sur created above will not boot. Technically, you could just run Big Sur/Monterey installers to update, but this is a PITA. So need to create a MAC OS SSD with HFS+ formatting. Newer versions of MAC OS don't support that, but High Sierra does. The problem here is that the installer script auto converts the SSD from HFS+ to APFS during installation, but this can be overridden.

        Create a HFS+ (MAC OS Journaled) formatted High Sierra installation SSD

        1. Boot to Recovery mode via a High Sierra USB installer, with a spare SSD fitted to install High Sierra on.

        2. In Disk Utility, format the SSD as Mac OS Extended (Journaled), call it Macintosh HD.

        3. Open Terminal and disable SIP, otherwise following command will not work:

        csrutil disable

        Reboot the machine, and boot from the USB installer again.

        4. Open Terminal and run

        /Volumes/"Image Volume/Install macOS High Sierra.app"/Contents/Resources/startosinstall --volume /Volumes/Macintosh\ HD --converttoapfs NO --agreetolicense

        Syntax here is very important. If you get an error, check things like Volume or Volumes and spacing.

        5. Once the setup is complete, create a user account and password. Don't bother with any updates (don't think they work anymore from the outdated App store in this version anyway).

        6. Insert the Big Sur USB installer, and extract the firmware files as listed previously.

        7. Update firmware using the Bless commands as before:

        820-3437 boards:
        sudo /usr/sbin/bless -firmware ~/Desktop/MBA61.scap --verbose --recovery

        820-00165
        sudo /usr/sbin/bless -firmware ~/Desktop/MBA71.fd --verbose --recovery

        As of 15/11/2023, current firmware versions are:
        476.0.0.0 for 820-3437
        481.0.0.0 for 820-00165

        8. Re-enable SIP from recovery mode

        csrutil enable

        Comment

        • David Sage
          New Member
          • May 2025
          • 1
          • India

          #5
          Not working for MBP114

          Comment

          Related Topics

          Collapse

          • TheUser
            Thinkpad Docker G2 Type-C 40AS - Firmware Unknown
            by TheUser
            Hello to everyone ,

            This is my first post here, and i would like to share with you a small story in case you can help me.

            Docker Type-C Gen 2 - Model 40AS. Was given to me by a friend for free ,but with the problem that you cannot use the video output ports.

            All ports work , USB , Ethernet, Type C ... but HDMI + Display Port don't work

            I searched on reddit and google for problem similar to that, and a LOT of people had fixed this problem by updating the firmware. So i tried , i searched and found 1.1.13 utility and 1.1.20 utility that can help...
            02-10-2024, 02:07 PM
          • rumpumpel1
            ThinkPad X12 Detachable Gen 1: keyboard after firmware update without function
            by rumpumpel1
            Lenovo System Update offered me an update for the firmware of the Folio keyboard for my X12 Detachable Gen 1. The update got stuck and after 20 minutes I switched off the laptop. Since then, the keyboard and touchpad have been without function. Does anyone know how I can revive it?
            10-24-2024, 08:59 AM
          • dkneyle
            Sony KDL-46HX850 Can't upgrade/update firmware
            by dkneyle
            Diagnosed this TV as having a failed main board which I've replaced with one from a KDL 55HX850. They are (supposedly) the same board.

            Being 'Smart TV' it requires a firmware reboot when you swap out boards such as T-Con or main board. It starts with a black screen and flashing yellow and green LEDS, indicating it needs that firmware boot. The procedure described all over the web is to put the software into the root directory of a FAT32 formatted USB drive and it should load that up once plugged into USB1 port. But not for me. I can see the LED on the USB chip flash for about...
            09-25-2024, 10:44 PM
          • pp74
            Marantz NR1508 USB firmware update image
            by pp74
            Does anyone happen to have the latest firmware for the NR1508? Marantz took their update server down and customer support refuses to provide the image to flash over USB.


            Regards
            05-10-2025, 11:55 PM
          • Faluky
            firmware for Marantz SR5008 stuck in update loop
            by Faluky
            After an update it stopped playing audio and video, I have reset it as it says in the manual and tried to reinstall the firmware over the internet but logging failed each time and I tried to download the firmware to install it by usb but it does not appear on the official page, could you help me? Since it would be a shame to have to get rid of him, European version Thank you very much
            Best regards.

            Anyone got their hands on firmware for Marantz SR5008 stuck in update loop
            01-17-2023, 04:33 AM
          • Loading...
          • No more items.
          Working...