Corrupted EFI after windows update

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Level 1

4 points

Corrupted EFI after windows update

TL;DR - macos and recovery doesn't work, apparently after windows update, though the windows itself runs ok.

There was a minor windows update (installed via bootcamp) a short time before, but maybe it's not an issue, but somehow after restarting my laptop in order to boot into macos in went into infinite bootloop.

CMD+R fails, internet recovery (both options CMD+OPTION+R+(SHIFT)) fails either after the preparations stage (it just reboots again into int. rec. mode) or gives -2100 or -2003 errors after downloading something.

I did reset NVRAM and SMC, but it didn't make any difference.

The only way to do something is to boot into windows with the alt key.

I wonder if there is any way to fix the problem from windows - if it's got the means to break things, there's probably some way to fix something. Additional issues are the main partition in T2 encrypted with filevault and, of course, there is no way to boot externally, again, due to T2 chip.

An interesring detail is a presence of EFI partition (the 300 MB one) (img 1)

(img 5) These logs must have been created by the internet recovery utility. Here are some lines from there:

APFSStart:1608: Mounting with apfs_efi_osx_aligned-1934.121.2
efi_fusion_pairing:691: Container a18a0741-317e-4d84-bb28-8a11342fc619
efi_fusion_pairing:696: fusion uuid: 00000000-0000-0000-0000-000000000000
efi_container_create:933: LoadedImage->DeviceHandle = 0x7a499818
efi_container_create:995: Volume attached is internal
nx_dev_init:834: warning: superblock indicates jumpstart record but this driver was not loaded from that partition
nx_mount:1184:  initializing cache w/hash_size 256 and cache size 4096
nx_mount:1460: checkpoint search: largest xid 11472612, best xid 11472612 @ 177
er_state_obj_get_for_recovery:6457: No ER state object for volume Preboot - rolling is not happening, nothing to recover.
er_state_obj_get_for_recovery:6457: No ER state object for volume Recovery - rolling is not happening, nothing to recover.
er_state_obj_get_for_recovery:6457: No ER state object for volume VM - rolling is not happening, nothing to recover.
#[PW]
#[SSR|>] Starting Recovery at 07/26/2023  04:46.
#[SSR|RM] 2
#[SSR|>] Network recovery selected.
#[SSR|>] BridgeOSVersion 19.16.15071.0.0,0

Also all of these files end with repetition of line "#[SSR|N] 3" in any quantity (difference between the logs on the image above is only in amount of those lines)

\EFI\BOOT contains only windows' bootx64.efi; \EFI\APPLE\EXTENSIONS contains only Firmware.scap

Also I've seen a similar topic (https://discussions.apple.com/thread/7182666) and checked wether the APFS'S GUID was fine, and it was.

Any ides on how the bootloader was corrupted and how to solve the problem?

MacBook Pro — Илья

Posted on Jul 27, 2023 5:49 AM

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Answer 1

Jul 27, 2023 10:08 AM in response to grizabela

there isn't a lot you can do without Internet recovery, and that requires access to the Internet is some fashion.

If you have another Mac running 12.4 or later, you could try a Revive from the other computer over USB cable:

Revive or restore a Mac with Apple silicon using Apple Configurator - Apple Support

otherwise you will need to contact apple support and arrange a visit to the Genius Bar and have them help.

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Answer 2

Jul 27, 2023 6:50 AM in response to grizabela

Internet Recovery is in the computer's ROM, and is essentially incorruptible.

<< gives -2100 or -2003 errors after downloading something. >>

In Internet Recovery, these low negative thousands error messages indicate that your provided Wi-Fi Network is inadequate in some fashion, and cannot be used (for this purpose) in its current state.

Common problems include:

Hidden Network-name

required use of a proxy server to get Internet access

required use of a login page to get Internet access

Use of a login server or certificate to get Internet access

Use of PPPoE in the Mac to get Internet access (typically only applies to DSL)

Use of Fixed IP address rather than good old DHCP

Variance of the time by more than five minutes

Failure of Router to provide workable DNS server addresses, or providing 0.0.0.0 [may produce -2002f]

If you have an Ethernet port, you may in some cases be able to move your Mac close to the Router and connect to the Router using Ethernet.

The higher the number, the more obscure the problem.

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Answer 3

Jul 27, 2023 6:54 AM in response to grizabela

what model-year MacBook pro?

2018 and after use the T2 chip, so some of what was in ROM is moved to a normally-inaccessible portion of the boot drive.

Apple-silicon Macs use a completely different method, but they do not run regular Windows.

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Answer 4

Jul 27, 2023 11:02 AM in response to grizabela

Did you try simply holding Option key at startup?

this should invoke startup manger, draw a gray screen and look around for Bootable Volumes. if any are found within about five minutes, its Icon will appear.

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Answer 5

Jul 27, 2023 2:29 PM in response to grizabela

The initial "chime" sound is generated in software when your Mac passes the Power-On Self Test. If the chime occurs and/or startup continues, your Mac is working. The blank gray screen should light up. Then on to the disk Drive.

Accessing the Boot drive:

The solid Apple is not in the Mac's ROM at Cold start. The Apple logo can only appear when it is fetched in the first "blob" of software loaded from a 'magic' place on the boot drive, or re-run after a Restart. Then a whole lot of stuff is initialized, and the progress Bar moves part way across. After a cold start, seeing the solid Apple appear says your drive was properly able to produce the software that contains it.

If a prohibitory sign appears at this point, it indicates some fundamental part of MacOS is damaged or wrong version.

Mounting the Boot drive:

The next step requires a lot of files by name, so the File System is initialized, and the Boot Drive is Mounted. If the drive directory is damaged, the drive can not be Mounted, so your Mac begins one pass of Disk Utility Repair. This will take an additional about five minutes. During this process, the progress bar may be extended, and will grow by an additional amount not seen on a routine startup.

at the end of that process (which should not take more than about five minutes), it will attempt to Mount the drive again:

-- if the drive Mounts, boot-up continues.

-- if the drive cannot be Mounted, your Mac can do nothing more, so it powers off.

-- if the process stalls, this may indicate you have Bad Blocks on your Rotating Magnetic Boot drive (if so equipped). The re-reading of Bad blocks can take a very long time (on the order of a quarter minute for each Bad Block).

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Answer 6

grizabela Author

Level 1

4 points

Jul 27, 2023 7:52 AM in response to Grant Bennet-Alder

I've seen those recommendation. I've tried internet recovery in different places with different networks, even tried removing the password from my wifi network (there was no possibility to connect ethernet because I don't have a dongle good enough), but in the best case and very rare it would give me some kind of error instead of just rebooting.

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