02-wifi-firmware.sh

Manages Broadcom BCM4377b Wi-Fi and BRCM4377 Bluetooth firmware for the MacBook Air 2020. Provides verification, backup, restore, and re-installation capabilities.

Usage

# Interactive menu
bash scripts/02-wifi-firmware.sh

# Direct subcommands
bash scripts/02-wifi-firmware.sh verify
bash scripts/02-wifi-firmware.sh backup
sudo bash scripts/02-wifi-firmware.sh restore
sudo bash scripts/02-wifi-firmware.sh install-pkg
bash scripts/02-wifi-firmware.sh guide

# Preview without changes
bash scripts/02-wifi-firmware.sh --dry-run
bash scripts/02-wifi-firmware.sh --help

Flag	Description
--dry-run	Preview all actions without modifying the system
--help	Show usage information and exit

Subcommands

Command	Root	Description
verify	No	Check that all required firmware files are present and test Wi-Fi/BT interfaces
backup	No	Copy firmware files to ~/.config/firmware-backup/brcm/ with a manifest
restore	Yes	Restore firmware from the backup directory and reload brcmfmac
install-pkg	Yes	Download and install the apple-bcm-firmware package from the arch-mact2 mirror
guide	No	Display the macOS firmware extraction guide for fresh installs

Firmware Files

The MacBook Air 2020 (board ID: fiji) requires:

File	Purpose
brcmfmac4377b3-pcie.apple,fiji.bin	Wi-Fi firmware binary
brcmfmac4377b3-pcie.apple,fiji.clm_blob	Wi-Fi regulatory data
brcmfmac4377b3-pcie.apple,fiji.txcap_blob	Wi-Fi TX power caps
brcmbt4377b3-apple,formosa.bin	Bluetooth firmware
brcmbt4377b3-apple,formosa.ptb	Bluetooth patch RAM

All files live in /lib/firmware/brcm/.

Backup Location

Backups are stored at ~/.config/firmware-backup/brcm/ with a MANIFEST.txt listing file sizes and backup date.

Files Modified

Path	Purpose
/lib/firmware/brcm/brcmfmac4377*	Wi-Fi firmware (restore/install-pkg)
/lib/firmware/brcm/brcmbt4377*	Bluetooth firmware (restore/install-pkg)
~/.config/firmware-backup/brcm/	Backup directory (backup)

Prerequisites

• curl (for install-pkg)
• Internet connectivity (for install-pkg)
• Backup must exist before running restore

Source

View the full source on GitHub.