How to Fix Prohibitory Sign Errors on Dell Precision M3800 running macOS Big Sur

How to Resolve Boot loader USB Mapping Stalls on Haswell Workstations

When downgrading a Dell Precision M3800 (Intel Haswell i7-4702HQ) from Ventura to macOS Big Sur, the system may boot to the Apple logo and display a prohibitory ("no entry") symbol. This behaviour indicates that the OS is unable to load driver resources from the USB drive because of incorrect USB mapping in the EFI folder.

1. Prerequisites

• Hardware Specs: Dell Precision M3800, Intel i7-4702HQ, Intel HD 4600 iGPU, NVIDIA Quadro K1100M (must be disabled).
• Required Kexts: Lilu, VirtualSMC, WhateverGreen, AppleALC, USBInjectAll.

2. Compatibility Snapshot

• Big Sur Support: Intel Haswell and HD 4600 graphics are natively supported in Big Sur.
• USB Controller Changes: Big Sur uses different USB controller stack configurations compared to Ventura, making Ventura-mapped EFI folders incompatible.

3. Installation Preparation

1. Avoid BalenaEtcher: Do not use BalenaEtcher or third-party partition editors to copy files to your EFI partition. Instead, format your USB installer as GPT/FAT32, create a standard installer using createinstallmedia, and mount the EFI using a script or terminal.

4. EFI and config.plist Review

1. USB Configuration: Add USBInjectAll.kext or enable XhciPortLimit under Kernel -> Quirks in config.plist. This ensures the USB ports remain active during kernel load.
2. Disable NVIDIA GPU: Add -wegnoegpu to boot-args.

5. Post-Installation

1. Create USB Map: Perform a clean USB port map using Hackintool specifically for macOS Big Sur.

6. Troubleshooting

Reported Issue: Stuck at prohibitory symbol

1. USB 2.0 port: Plug the installer USB into a USB 2.0 port if the USB 3.0 ports drop offline during boot.
2. Clean config: Do not use generic configurations. Take your working Ventura config.plist and modify the SMBIOS to MacBookPro11,4 or MacBookPro11,5.

7. Dual Boot and Advanced Configuration

• Dual booting Windows and Big Sur is supported. Keep them on separate partitions.

8. Verification, Maintenance and Rollback

• Verify Fix: Ensure the Big Sur installer screen loads without displaying the prohibited sign.

9. References and Glossary

• Prohibitory Symbol: A screen displaying a circle with a slash, indicating macOS cannot locate a bootable system partition.