Is there still something amiss in the M1 firmware?

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Style Pass

2021-06-18 08:00:07

Wonderful though the M1 Mac’s new Recovery system is, there’s a problem which has been plaguing a few users since the first of the new models shipped late last year. When in Recovery (or elsewhere) you erase your Mac’s internal storage to reinstall macOS, just when you start that reinstallation, up pops up the error message: “An error occurred while preparing the update. Failed to personalize the software update. Please try again.” I explained this, and linked to Apple’s support page, in this article on 26 November, almost seven months ago, yet users still encounter this in macOS 11.4 and in current beta-releases.

Perhaps inevitably, Apple neither explains what is going wrong, nor does it tell us how we can avoid this from happening, other than by avoiding erasing internal storage in this way. Neither does it make clear that the erasure doesn’t actually erase the whole disk, only its macOS container. This still leaves two other containers, with the ‘firmware’ and recoveryOS on them, which can only be completely erased when you boot your M1 in DFU mode and restore from an IPSW image, something Apple details in this article from the Configurator Help book.

The evidence from Apple’s advised solutions only strengthens the case that this is a continuing bug in the firmware or recoveryOS, or possibly in the Big Sur installer. It’s a serious bug too: although it occurs infrequently, solutions are quite technically challenging and the only way to recover that Mac.