Follow the documented procedure for how to prepare a bootable flash drive with the installer image.
On my MacOS system the process went as follows. Starting by listing all disks and trying to identify the usb thumb drive.
$ diskutil list /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *256.1 GB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_CoreStorage Untitled 255.2 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3 /dev/disk1 (internal, virtual): #: TYPE NAME SIZE IDENTIFIER 0: Apple_HFS Macintosh HD +254.8 GB disk1 Logical Volume on disk0s2 3E5B13F2-1D82-4CD2-8369-110D3B86D481 Unencrypted /dev/disk2 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: *8.1 GB disk2
The 8GB usb thumb drive is listed as /dev/disk2, this needs to be unmounted using the below command.
$ diskutil umount disk2 disk2 was already unmounted or it has a partitioning scheme so use "diskutil unmountDisk" instead
Now write the installer image to the usb thumb drive.
$ gzcat pfSense-CE-memstick-2.3.4-RELEASE-amd64.img.gz | sudo dd of=/dev/rdisk2 bs=1m Password: 0+10833 records in 0+10833 records out 709894144 bytes transferred in 68.655711 secs (10339914 bytes/sec) $
Boot from the usb stick, following the onscreen instructions and selecting the defaults.
Reboot and remove the usb flash drive, pfSense will now boot natively.
Once the system has started visit https://192.168.1.1 and follow the setup wizard.
After the setup wizard completes the configuration is reloaded and a login page is presented. Login using admin and the new password.
Once logged in the status dashboard is displayed.
Configure to taste.