System Extensions in Big Sur
Don't install Big Sur until you make sure your
USB/Serial connection will work!
for Legacy System Extensions started to appear on reboot after
installing macOS 10.15.4
These extensions are provided by the manufacturers (FTDI,
Silicon Labs etc.) of internal and external USB/Serial adapters
(UARTS) and are needed for CAT control of all serial port
(non-LAN) based radios, rotor controllers, etc.
intends to eventually prohibit kernel extensions for security
reasons and replace the functionality with DriverKit extensions
running in user space.
UART manufacturers have announced their intention to support
Apple's migration from Kernel Extensions to DriverKit Extensions.
Many UARTs are already supported automatically by Apple supplied
Driver Kit extensions in the Big Sur beta.
As Apple System Extensions and DriverKit adds functionality,
kernel extensions with matching functionality will not load.
Status October 1,
2020 macOS Version 11.0 Beta 9 (20A5384c). Updated
as more information becomes available.
are not sure that your device will be supported please do not
upgrade your Mac to Big Sur without being able to fall back to
your current version of macOS.
The Big Sur beta DriverKit currently supports the
following devices without the end user having to install any
All devices tested so far including...
- CP2102 (IC-7300, IC-9700, TS-590 etc.)
All devices tested so far.
The Big Sur beta does not currently support the following
- Disable SIP (not usually recommended
- proceed with caution).
- Shutdown Mac
- Hold <command> R during startup
until Apple Logo
- Run Terminal from Utilities menu
- csrutil disable
- Install SiLabs driver
Tested here with Yaesu
may not be possible when Big Sur is officially released.
- Use an FTDI based UART cable with
the Radio's back panel RS-232 DB-9 serial CAT port.
Tested here with Yaesu FT-991 and Prolific, FTDI