pfSense documentation site ( “Installing pfSense”, “Writing Disk Images” and especially “ALIX BIOS Update Procedure”

PC Engine How to create a FreeDOS bootable CF card (LBA image) (

Mark Shroyer ALIX Board Setup (

What you need: A null modem, a CF card (and CF card reader), physdiskwrite and putty or something similar.

Depending on you need to update the ALIX BIOS, you will possibly also need an extra CF card (8 Mb (yes – MB, not GB) is enough) as re-sizing CF cards can be very tricky. ALIX BIOS needs to be on version 0.99h or higher before you can install pfSense.

Putty (
Win32 Disk Imager for backup.
Kingston CF Ultimate 266x - 16GB for the pfsense image. (2 GB card is minimum)
Physdiskwrite (
PC Engine update image: alixupdate_0.99h_freedos.img.gz.
pfSense image: pfSense-CE-2.3.2-RELEASE-4g-i386-nanobsd.img.gz (use newest)

Note regarding null modem: Used a DSUB9 female - DSUB9 female null modem cable. Possibly a problem for most, as serial port are not really standard. USB/serial null modem cables exist, but these I have not tested. Something to check out before you start.

Note regarding BIOS version: Using PC Engine BIOS version 0.99h. A newer version exist (ALIX tinyBIOS v0.99m (1/17/2014)). Should be preferable. See more at

0) Backup existing CF card.

If you are updating a running monowall installation or something similar, it is nice to be able to restore your functioning box, if things turn sour. Therefore start with writing a backup image of the existing CF card. Win32 Disk Imager is an option for that.

1) Update ALIX 2D board (the worst part)

You could start by trusting you luck, and simply downloading and write the pfSense image to the CF card. Insert the new card, connect null modem and power up: If the initial setup is running OK, then you are all set. No need for updating the board. If you get something like the screenshot below, you will have to update.

error booting pfSense

Alternative methods exist for updating the BIOS. If you do not feel like formatting your 16 GB CF card for 16 MB, these methods are worth looking at. Writing alixupdate_0.99h_freedos.img to the CF card, will on give you 16 MB total space no matter what size your card is, and re-formatting can be tricky.

a) Download the file from PC Engine ( The image include both FreeDOS and the BIOS update. Extract the zip file (alixupdate_0.99h_freedos.img)

b) Write alixupdate_0.99h_freedos.img to CF card.

Disclaimer: Writing the 16 MB image to the CF card, can result in permanently reducing the card for 16 MB. i.e. you are stuck with a 16MB CF card.

When using physdiskwrite be extremely careful. Physdiskwrite can (attempt to) overwrite any disk on your computer – including OS (Defualt physdiskwrite will not overwrite any disk larger that 2 GB without the -u parameter set). Therefore make a minor detour with diskpart.

1) Make sure you know the correct disk number of the CF card.
2) Clean the CF card (after you are 100% certain which disk is the CF card)

Do not do anything with diskpart, unless you feel really comfortable with it. Again; you can accidental delete you OS disk with diskpart. Windows disk manager can also show you the disk number for the CF card.

Detour with diskpart.

Disk # 2 is the CF card. If in doubt: Exit diskpart, remove CF card. Start diskpart again: The missing disk is your CF card. Errors with diskpart can be really, really tiresome and time consuming and worth avoiding.

Link for hints with diskpart:

With the correct disk number for the CF card, you can write the alixupdate_0.99h_freedos.img image to the CF disk (at long last …)

Copy both image file (alixupdate_0.99h_freedos.img ) and physdiskwrite.exe into same directory. Use an elevated command prompt (run CMD as administrator).

physdiskwrite must complete the write successfully.

c) Putty

Setup a serial connection, with 38400 baud, eight data bits, one stop bit, no parity, and XON/XOFF flow control.

Insert the CF card on ALIX. Connect null modem and connect power. During memory test press ‘S’ to access BIOS configuration. Follow the description by Mark Shroyer:

Press the number 1 to change the BIOS's serial console rate to 115200 baud (in order to make serial file transfers bearable, if necessary), L to enable LBA mode on the CF card, and then U to enable Ultra DMA. Also press E to enable PXE booting. Finally, press Q to quit. When prompted, confirm that you wish to persist these changes to flash.

Disconnect your serial terminal, then reconfigure your terminal software to communicate with the ALIX board at the new rate of 115200 baud. ( or (
After re-connecting putty run “” from the FreeDOS prompt, to reprogram flash. The update will complete shortly.

b) Write pfsense image.

Writing the pfSense image to a CF card, is very well documented in pfSense How-to documents, and basically the same steps you have just taken to write the FreeDOS image – except with a different image. PfSense How-to

psSense image must be 32-bit with serial console (not vga). If your CF card is larger than 2 GB, you can choose the 4 GB image (The 4 GB image was written fine to my 16 GB card).

Some patience is necessary: The initial pfSense configuration will take some time. Keep the putty session open to follow the install progress.

Run the basic wizard and start adding your rules and stuff.