macOS Sonoma Boot Failure Issue Identified

The Asahi Linux team has identified two bugs that may result in boot failures in macOS Sonoma and macOS Ventura (version 13.6). While all Mac models may encounter upgrade-related boot failures, MacBook Pro models with the ProMotion display are particularly affected. Users experiencing this issue will not lose data but will need to perform DFU recovery from another Mac.

When upgrading to macOS Sonoma or macOS Ventura 13.6, machines utilize the previously installed OS for System Recovery. However, the Asahi Linux team has discovered that older versions of recoveryOS are not fully compatible with Apple's latest firmware. If a bug, update process, or boot process causes macOS Sonoma to enter recoveryOS, the recovery environment may fail to boot, resulting in a black screen. (As macOS Ventura 13.6 shares the same firmware as macOS Ventura, it is also impacted by this issue.)

All Macs are susceptible to the recoveryOS bug. However, users of MacBook Pro models with the ProMotion display face an additional issue. If the default ProMotion refresh rate setting is not used in macOS Sonoma or Ventura 13.6, the ability to boot into previous macOS installations will be lost. This is because System Recovery relies on the previously-installed OS version, and any interaction with System Recovery during booting or updating will result in boot failure.

Moreover, Asahi Linux users are at an added risk from the ProMotion display bug. If they fulfill the aforementioned criteria and attempt to boot Asahi Linux, they will encounter boot failure. This is because Asahi Linux behaves similarly to older versions of macOS.

Please refrain from installing the macOS Sonoma or macOS Ventura 13.6 updates until Apple addresses these issues. If you have already updated, please wait for a fix to be released. MacBook Pro owners with a ProMotion display should ensure that they are using the default refresh rate setting. If you experience boot failure, try booting into recoveryOS and performing a DFU recovery from another Mac. The latest Asahi Linux installer now includes a recoveryOS diagnostic tool. If desired, you can exit the Asahi installation process after using this tool.

We have contacted Apple for further information and will update this article if they respond.

Source: Asahi Linux

Editor's P/S

As a Gen Z fan, I am deeply concerned about the macOS Sonoma boot failure issue, particularly its impact on MacBook Pro models with the ProMotion display. This issue not only causes significant inconvenience for users but also puts their data at risk. The fact that older versions of recoveryOS are not fully compatible with Apple's latest firmware is a major oversight that should have been addressed before the release of macOS Sonoma.

Furthermore, the additional issue faced by users of MacBook Pro models with the ProMotion display, where the ability to boot into previous macOS installations is lost if the default ProMotion refresh rate setting is not used, is unacceptable. This issue effectively prevents users from downgrading their operating system or using alternative operating systems like Asahi Linux.