Recent updates to macOS Sequoia 15.4, Sonoma 14.7.5 and Ventura 13.7.5 brought firmware updates for some Macs, but not others. As I have now analysed those, and they’re reflected in the databases accessed by SilentKnight, and in my reference articles here (listed at the end), this article explains which are still being maintained by Apple.

Intel Macs without T2 chips

There are only two models of Mac without a T2 or Apple silicon chip whose firmware is still supported for updates: the iMac19,1 and 19,2, respectively the 2019 Retina 5K 27-inch and Retina 4K 21.5-inch. In this round of updates, they moved up to an EFI version of 2075.100.3.0.3, dated as recently as 3 March 2025. As they can run Sequoia, they’re expected to have continuing macOS security updates until at least the summer of 2027.

Older models of iMacs, MacBook Pros, and a single MacBook, remain with EFI firmware that was last updated in June 2024, and is unlikely ever to be updated any further. macOS support for them is expected to end when security updates for Ventura are discontinued at the end of the summer this year.

T2 Macs

For the 20 days between the release of 15.3.2 and 15.4, Intel Macs with T2 chips that were running Sequoia had a slightly more recent release of iBridge firmware. In 15.3.1, 14.7.4 and 13.7.4, that was 22.16.13051.0.0,0, but 15.3.2 brought version 22.16.13060.0.0,0. This is one of very few occasions in which T2 Macs running supported versions of macOS have had different firmware versions installed.

Thankfully, this last round of updates has rectified that, and all Macs with T2 chips should now be running 2075.101.2.0.0 (iBridge 22.16.14248.0.0,0). This is encouraging, not only for simplicity, but because it demonstrates that Apple is continuing to support not only the ‘Bridge’ Arm chip, but EFI as well. How much longer that will continue depends on whether there is Intel support in macOS 16, expected to be announced at WWDC in early June, and released in September or October this year.

At a minimum, macOS support for T2 Macs should last at least until summer 2027, and that should be extended to the following year if macOS 16 comes with Intel support.

Apple silicon Macs

All Apple silicon Macs should now be using iBoot version 11881.101.1, which was installed with these updates. The most recent MacBook Air and Mac Studio models with M4 family (or M3 Ultra) chips had their own update to 15.3.2, but 15.4 covers all current models in the single distribution, with the same firmware version.

There’s a growing number of reports of Apple silicon Macs experiencing problems updating to Sequoia 15.4, either on their internal SSD or on bootable external disks. This seems most likely in models with M1 family chips, and suggests that changes made in the installer might be responsible. As this doesn’t appear to affect 14.7.5 or 13.7.5 updates, it’s unlikely to lie in the firmware. There are several strategies you can adopt to work around this, including:

• Try updating in Safe mode. This is a longstanding function of Safe mode, described here.
• Start up in the correct paired Recovery system, and install Sequoia there. This should be attempted conservatively, without creating a fresh Data volume, but you must ensure that you have at least one complete backup ready in case anything goes wrong and the whole boot volume group has to be replaced.

Provided the Mac is already running at Full Security, there shouldn’t be any value in changing that. Performing a full Restore in DFU Mode isn’t as daunting as it might seem, but is a drastic solution requiring a recent second Mac, and full restore from your backup. If you’re getting to that stage, contact Apple Support who hopefully will now be only too familiar with these problems.

Summary

• Intel Macs without T2 chips: iMac19,1 and 19,2: EFI 2075.100.3.0.3; no change in other models.
• Intel Macs with T2 chips: 2075.101.2.0.0 (iBridge 22.16.14248.0.0,0).
• Apple silicon Macs: 11881.101.1.

Reference data

Which firmware should your Mac be using? (version 9, Sequoia)
Which firmware should your Mac be using? (version 8) – for Sonoma
Which firmware should your Mac be using? (version 7) – for Ventura

Good news: almost exactly three years after I reported that you couldn’t control what an Apple silicon MacBook Pro or Air does when you open its lid, Apple has addressed this.

Intel models

Since about 2016, Intel MacBook Air and Pro models may have an ‘auto boot’ feature, and either start up or wake from sleep when you open their lid. This behaviour is controlled by the AutoBoot setting in their NVRAM. If you want to disable auto boot startup, then open Terminal, type in the command
sudo nvram AutoBoot=%00
and authenticate with your admin password. When you next open the lid, that Mac won’t start up until you tell it to.

To disable that, and restore auto boot, enter the Terminal command
sudo nvram AutoBoot=%03
and authenticate again. It will also be restored if you reset NVRAM.

Apple silicon models

The procedure for Intel Macs doesn’t work in Apple silicon models, and the NVRAM setting that looked as if it might work, auto-boot, mustn’t be used as it can cause boot problems. Leave it well alone unless you fancy performing a full restore in DFU mode.

According to Apple’s recent support note, it’s now possible to change auto boot behaviour in MacBook Air and Pro models with Apple silicon chips using the BootPreference setting, when they’re running macOS Sequoia.

To disable auto boot when opening the lid or connecting to power, enter the Terminal command
sudo nvram BootPreference=%00
To disable auto boot when opening the lid, but for it still to work when connecting to power, enter the Terminal command
sudo nvram BootPreference=%01
To disable auto boot when connecting to power, but for it still to work when opening the lid, enter the Terminal command
sudo nvram BootPreference=%02

To restore normal auto boot behaviour, enter the Terminal command
sudo nvram -d BootPreference
to delete that setting in the NVRAM.

You can also list the contents of NVRAM with the command
nvram -p
which is helpful when you’re not sure what the setting is, or whether it has been removed from NVRAM altogether to return that Mac to its default behaviour.

Be particularly careful when making any changes to the NVRAM in an Apple silicon Mac: if you make a mistake there’s no easy way to reset the NVRAM, and your Mac could be taking a trip to DFU mode before it will work properly again.

Cleaning keys or trackpad

Auto boot only determines start up behaviour on opening the lid or connecting power. When the lid is open, pressing any key or using the touchpad will still cause the Mac to start up, so limiting use for cleaning its keys or touchpad. Apple recommends using compressed air, which shouldn’t start the Mac up, but if you prefer to use a dry cloth or isopropyl alcohol on a cloth (but never a water-based cleaner), then you may find it helpful to use KeyboardCleanTool to block key entry during cleaning.

Whatever you do, don’t let any water=based liquid near your Mac’s keyboard or other areas that could allow its ingress. Even small amounts of water can cause serious damage that can require expensive repairs. Like all laptops, MacBook Air and Pro models contain multiple water sensors, making that damage easy to detect. Water damage is included in AppleCare+, but will still cost you $299, and may not be covered by other insurance policies.