Author Archives: gonzo

FreeBSD, BBB and 4DCAPE-43T

Short demo of FreeBSD running on Beaglebone Black with 4DCAPE-43T


I used vendor-provided am335x-boneblack-4dcape-43t.dts file to generate dtb, you can download compiled blob here. The system running on demo is gpiokeys branch of my git repo: . Patch against -head is here.

If you’re interested only in LCD screen – it’s supported by -head but you’ll need to either add device gpiobacklight to BEAGLEBONE kernel config or enable LCD backlight manually using gpioctl: gpioctl -f /dev/gpioc1 18 1. gpiokeys is somewhat more complex thing and still WIP, there are some pieces missing in HEAD I had to hack around to make them work. And I haven’t started research on touchscreen yet.

FDT overlays in FreeBSD

FDT overlay is an extension to FDT format that lets user to modify base FDT run-time: add new nodes, add new properties to existing nodes or modify existing properties. It’s useful when you have base board and some extension units like cape/shield for Pi/BBB or loadable FPGA logic for Zynq. I will not go into details you can find internals described on Adafruit or Raspberry Pi websites.

When dealing with overlays there are two options where to handle them: loader or kernel. Managing overlays at kernel level gives more flexibility but requires more related logic, e.g. re-init pinmux after applying overlay, re-run newbus probe/attach. On the other hand loader-level support is quite straightforward and involves nothing but DTB modifications and it’s a natural first step to adding FDT overlays to FreeBSD.

Proposed solution is to add fdt_overlays variable that contains coma-separated list of dtbo files, e.g.: “bbb-no-hdmi.dtbo,bbb-4dcape-43.dtbo”. This variable can be defined either as a loader(8) variable or as a u-boot env variable. During the boot ubldr load base DTB and right before passing control to the kernel it would go through files, load them from /boot/dtb/ direсtory on root partition and apply to the base blob. Final DTB would be passed to kernel.

You can find patch and review comments to it on Differential site: D3180. It contains:
- Extension to dtc to generate dynamic symbols and fixup info.
- ubldr fdt_overlays support

As Warner Losh mentioned it’s not clear yet how to deal with dynamic symbols support patch. It’s not part of official dtc tree though it’s accepted by RPi and BBB communities.

HDMI progress and 4DCAPE-43 support for Beaglebone Black

HDMI support for Beaglebone Black is stable now and supports reading EDID, you can get the path here. Before committing it I’d like to make interoperability between HDMI framer and FB/LCD drivers as generic as possible and for this I need at least one more system with working HDMI to find common patterns. For this purpose I picked up i.MX6-based Hummingboard and now try to get video output working on it. There is some minor progress but it seems before getting to HDMI/IPU I need to do some work on clock management part of the system. So it’s going to be some time before I see first pixels on my monitor.

I also got 4DCAPE-43, neat Beaglebone Black LCD cape by 4D Systems. Patch (download here) for it is pretty minimal: VT support in kernel config, panel info and pins configuration in dts, and one improvement in GPIO driver (setting default values for OUT GPIO pins). None of the other features except reset button work yet but getting GPIO keyboard working would be an interesting project by itself.

Here is the picture of cape in action:


HDMI support for Beaglebone Black: first milestone

Today for the first time I’ve got stable and correctly positioned output on HDMI monitor connected to BeagleBone Black. It involved fixing bug in AM335x LCDC controller, fixing bug in I2C controller, and a lot of experiments with register-pushing. Code requires major clean-up and is not ready for the tree yet. I’ll post patch when it’s in readable form.


Qt5 for FreeBSD/Pi

Build SD card image using crochet-freebsd with option VideoCore enabled. Mount either SD card itself of image to build host

mount /dev/mmcsd0s2a /pi

Checkout Qt5 sources and patch them

cd /src
git clone git:// qt5
cd qt5
git checkout 5.4.0
./init-repository --module-subset=$MODULES

fetch -q -o - | patch -p1

Configure, build and install Qt5 to SD card

./configure -platform unsupported/freebsd-clang -no-openssl -opengl es2 -device freebsd-rasp-pi-clang -device-option CROSS_COMPILE=/usr/armv6-freebsd/usr/bin/ -sysroot /pi/ -no-gcc-sysroot -opensource -confirm-license -optimized-qmake -release -prefix /usr/local/Qt5 -no-pch -nomake tests -nomake examples -plugin-sql-sqlite

gmake -j `sysctl -n hw.ncpu`
sudo gmake install

You need BSD-specific plugins to enable mouse and keyboard input in EGLFS mode

cd /src/
git clone
cd qt5-bsd-input
sudo gmake install

Build application you’d like run and install it. I use one of the examples here

cd /src/qt5/qtbase/examples/opengl/cube
sudo gmake install

Unmount SD card, boot Pi, make sure vchiq is loaded

root@raspberry-pi:~ # kldload

Start application

root@raspberry-pi:~ # /usr/local/Qt5/examples/opengl/cube/cube -plugin bsdkeyboard -plugin bsdsysmouse

If you see something like this:

EGL Error : Could not create the egl surface: error = 0x3003

Or this:

QOpenGLFramebufferObject: Framebuffer incomplete attachment.

It means you need to increase GPU memory by setting gpu_mem in config.txt. Amount depends on framebuffer resolution. 128Mb works for me on 1920×1080 display.

bsdsysmouse plugin uses /dev/sysmouse by default, so you either should have moused running or specify actual mouse device, e.g.:

root@raspberry-pi:~ # cube -plugin bsdkeyboard -plugin bsdsysmouse:/dev/ums0

bsdkeyboard uses STDIN as input device, so if you’re trying to start app from serial console it should be something like this:

root@raspberry-pi:~ # cube -plugin bsdkeyboard -plugin bsdsysmouse < /dev/ttyv0

Update on ioquake/ARM for FreeBSD: controls support added

I’ve update ioquake binaries and pushed respective changes to github. New version has support for mouse and keyboard so you can actually play Quake3 on FreeBSD/Pi alas without sound. It should run out of the box on normal console. Make sure you have moused running or specify mouse device by setting Q_MOUSE_DEV environment variable, e.g.:

env Q_MOUSE_DEV=/dev/ums0 ioquake3.arm +set s_initsound 0

Audio on Raspberry Pi

With stable VCHIQ driver next obvious target was to add VCHIQ-based audio support. So let me introduce to you: vchiq_audio, first take. It’s part of vchiq-freebsd repo so if you use Crochet to build SD card image just enable option VideoCore in config file and module will be automatically included.

From shell run kldload vchiq_audio and you’re good to do. I believe that audio output is picked up automatically by VideoCore so if you have HDMI connected it’s probably going to be HDMI. I do not have device to confirm this. Adding knob to control audio output (auto, headphones, HDMI) is on my ToDo list.

Quality is not ideal though. From quick tests it seems to work fine on system with rootfs on NFS but there are audio drops on SD-based system while playing mp3 over NFS. I’m going to debug and stresstest it more thoroughly next week.

Short instruction on how to install mpg321 package on RPi:

env PACKAGESITE= SIGNATURE_TYPE=none pkg bootstrap

mkdir -p /usr/local/etc/pkg/repos
cd /usr/local/etc/pkg/repos
echo 'FreeBSD: { enabled: no }' > FreeBSD.conf

cat > chips.ysv.conf <<__EOF__
chips.ysv: {
  url: "",
  mirror_type: "http",
  signature_type: "none",
  enabled: yes

pkg install mpg321

RaspberryPi, FreeBSD and ioquake3

After New Year I got back to hacking the VCHIQ stuff (thanks to adrian@ for prodding). Since last time I touched NetBSD folks got it merged to main tree, syncing with latest upstream code and fixing some stupid bugs in my codebase. So I partially merged things back, spent some time on fixing more bugs introduced by yours truly, merged userland bits from latest Broadcom’s bits (and fixing some bugs introduced by them). And as a result VCHIQ got stable enough to run ioquake3d on raspberry pi. Well, you can’t play it because there is no sound and no mouse support and keyboard support is severely crippled but you can navigate menus and watch demoes.

Here is short summary of how to get it running:

  • Get latest HEAD that includes r276794
  • Get latest crochet-freebsd
  • Create configuration file for RasspberryPi, make sure that it’s configured for 2Gb SD card and has VideoCore enabled. i.e. it contains:
    option ImageSize 1950mb # for 2 Gigabyte card
    option VideoCore
  • Build RPi image and flash to SD card
  • mount FreeBSD partition, e.g. mount /dev/mmcsd0s2a /mnt
  • Copy Quake3 PAK files to /baseq3 directory on SD card
  • Download and copy *.so files to /baseq3 and ioqake3.arm to /usr/bin on SD card
  • Unmount FreeBSD partition and mount boot partiotion, e.g. mount_msdosfs /dev/mmcsd0s1 /mnt
  • Edit config.txt and change gpu_mem value to 64
  • Unmount SD card and boot it on your Pi
  • Load vchiq module: kldload vchiq
  • Start Quake3: ioqake3.arm +set s_initsound 0

Keyboard support is really broken. TAB and ENTER works, so you can navigate menus. But that’s pretty much it.

ioquake3 codebase with my minor changes located here:
I provide pre-compiled binaries because for some reason ioquake3 built with xdev tools crash in qsort (libc incompatibilities?) so I use make buildenv to build it.

And here is photo of demo in action (there are RaspberryPi and ZedBoard on it too, yay!)
Photo Jan 07

State of FreeBSD/MIPS emulation

A week ago Adrian Chadd asked me to take a loot at FreeBSD/MIPS emulation. So last week I’ve been busy tidying up stuff in that department and looking up bits of information on various emulators. This morning I finally committed last changeset so now is the time to write up summary.


There are two widely used MIPS emulatoes that FreeBSD supports: QEMU and GXemul. Both of them support numerous MIPS devices but we’re interested in only two.

MALTA is more or less standard for MIPS emulation and supported by both emulators. QEMU supports 32 and 64 bit variants with both big and little-endian byte order. So four modes in total. Also for MALTA machine QEMU provides PCNet NIC emulation.

GXemul supports 32 and 64 bit modes of MALTA but only for little-endian byte order. Big-endian byte order is not supported due to incomplete PCI controller implementation. No NIC support for MALTA machine. Also Gxemul provides so-called oldtestmips emulation mode: generic implementation of abstract MIPS machine with very simplified NIC/disk devices. In theory it should be faster then actual hardware emulation but I haven’t got around to benchmarking yet. oldtestmips can be run in 32 and 64 bit mode, but only big-endian byte order is supported.

Disk images

I used raw disk images created by makefs(8) utility. The advantage of raw disk image is that they can be used with both emulators. qemu provides more options in this area but they’re out of scope of this article. I created four images for my tests: disk.img, disk64.img, diskel.img, and disk64el.img. 32-bit big-endian, 64-bit big-endian, 32-bit little-endian, 64-bit big-endian. The process looks somewhat like this script:

set -e

export TARGET=mips
export TARGET_ARCH=mips
export SRCCONF=/dev/null
export SRCROOT=/src/FreeBSD/head
export MAKEOBJDIRPREFIX=/src/FreeBSD/obj/head
export DESTDIR=/src/FreeBSD/tftproot/$TARGET_ARCH
make -C $SRCROOT buildworld

sudo -E mkdir -p /src/FreeBSD/tftproot/$TARGET_ARCH

# modify /etc/fstab and /etc/rc.conf in $DESTDIR

# Create 512Mb disk image with big-endian UFS
# For TARGET_ARCH set to mipsel or mips64el use "-B le" switch 
sudo -E makefs -M 538968064 -B be /src/FreeBSD/disk.img $DESTDIR

Change TARGET_ARCH and disk image name accordingly for mipsel/mip64/mips64el targets.


As of QEMU 1.6.0 there is one known problem with it: NIC emulation does not work in big-endian mode. See this patch for fix and details. Also, amount of memory limited to 128Mb. Use MALTA kernel config for 32-bit mode and MALTA64 for 64-bit mode.

Command lines for various modes/byte orders are:

qemu-system-mips -M malta -kernel /path/to/mips.mips/MALTA/.../kernel -hda /src/FreeBSD/disk.img -nographic
qemu-system-mips64 -M malta -kernel /path/to/mips.mips64/.../MALTA64/kernel -hda /src/FreeBSD/disk64.img -nographic
qemu-system-mipsel -M malta -kernel /path/to/mips.mipsel/.../MALTA/kernel -hda /src/FreeBSD/diskel.img -nographic
qemu-system-mips64el -M malta -kernel /path/to/mips.mips64el/.../MALTA64/kernel -hda /src/FreeBSD/disk64el.img -nographic


GXemul requires two patches for proper FreeBSD/MIPS emulation. First one implements rdhwr op for reg 29 required by TLS support. The second one fixes UDP packet checksum calculation and required for proper functioning of emulated DHCP server. Both of these patches have been committed upstream but there were no GXemul release after that so they’re not available as part of emulators/gxemul port.

As with QEMU kernel configs for MALTA are MALTA and MALTA64. And since only little-endian byte order is supported command lines for this emulation mode are:

gxemul -e malta -C 4Kc -d /home/gonzo/FreeBSD/diskel.img /path/to/mips.mipsel/.../MALTA/kernel
gxemul -e malta -d /home/gonzo/FreeBSD/disk64el.img /path/to/mips.mips64el/.../MALTA64/kernel

For oldtestmips emulation mode is other way around, only big-endian. And to make things more complicated it’s GXEMUL kernel config for 64-bit and GXEMUL32 for 32-bit. So here you are:

gxemul -M 256 -E oldtestmips -d /home/gonzo/FreeBSD/disk64.img /path/to/mips.mips64/.../GXEMUL/kernel
gxemul -M 256 -C 4Kc -E oldtestmips -d /home/gonzo/FreeBSD/disk.img /path/to/mips.mips/.../GXEMUL32/kernel

Maximum amount of memory set could be set by -M command-line switch for oldtestmips emulation is 256M. Otherwise physical memory would overlap with memory-mapped regions reserved by devices. There are some preliminary work to work around this limitation but no results yet.

Update on FreeBSD/armv6 in QEMU

QEMU support in FreeBSD/armv6 regressed since I tried it last time few months back. Changes in FreeBSD kernel and in QEMU itself revealed bugs that were masked by previous behaviour.

In FreeBSD it was r248467: the way memory/IO resources are activated on FDT bus has been changed and it triggered bug in versatile_pci.c

The other issue is more complex. It seems that PCI IRQ routing in QEMU was out of sync with real hardware. So after commit 66a96d7018b9cbabb73c9b87b62a37e4cc46580a IRQ numbers assigned to PCI devices by FreeBSD kernel by default were invalid. Authors of QEMU eventually added compatibility knob to fall back to previous logic. So if you’re using QEMU 1.5 or later add this option to your command line:

-global versatile_pci.broken-irq-mapping=1

USB driver for FreeBSD/Beaglebone

It took me two months but I finally got back to hacking on musb driver for FreeBSD (the one that is used in TI AM335x-based devices like Beaglebone or Beaglebone Black). Previous revision turned out not to be ready for production. Here is the new one: beaglebone-usb-20130626.diff. I adopted it to latest HEAD, fixed numerous bugs, added support for SPLIT transactions and USB suspend/resume signalling. There is some cleaning-up to do but unless something major comes up the plan is to commit it over next few days.

Raspberry Pi console

Quick hint. If you did not disable “device sc” in kernel config all the message from kernel go to video console. But if something bad happened after kernel started and before framebuffer driver is activated all you’ll see would be “Kernel args: (null)” message on serial console which is not very helpful. So in order to debug this problem and have kernel boot messages on both monitor and serial port without recompiling kernel just add following line to /boot/loader.rc on SD card:

set boot_multicons="YES"

Work in Progress: LCD driver for AM335x evaluation module

I’m trying to wrap up some project I started working on quite some time ago and this is first chunk of clean-up.

Patch contains:

  • Kernel config for AM335x EVM
  • dts file for AM335x EVM with TFT panel info
  • LCD controller driver with some functionality missing: only 24/32 bit depth and only TFT mode is supported
  • Really simple PWM driver. LCD backlight is controlled through eCAS submodule of PWMSS0 module.

I tested it only on evaluation module, although I think with proper panel/pinmux configuration it should work with BeagleBone’s LCD caps too.
Parts missing: adjusting clock to proper pixel frequency, proper allocation of framebuffer memory.

FDT driver skeleton generator

Writing new driver for FDT-based device always involves several simple steps:

  • writing generic newbus driver skeleton
  • Checking for compatibility of node in probe routine
  • Allocate memory/IRQ resources in attach routine

I can’t say for other developers but I just copy existing driver, remove all device-specific stuff and rewrite generic stuff. Which is less time-consuming then writing it from scratch but time-consuming it is. Being huge fan of automation of any kind I decided to let computer do all this dumb work and leave creative part (copy-pasting registers definition from spec to code) to myself. the result is this script.

Developer feeds driver description in YAML format to the script and gets driver skeleton that requires minimal amount of editing to get it compiled. Driver description includes author name, prefix for macroses, prefix for newbus method-functions, FDT compatibility string, driver name and number of IRQ/MEMORY resources. A minute saved is a minute earned.

YAML example:

AUTHOR: Oleksandr Tymoshenko <[email protected]>
PREFIX: am335x_pwm
DRIVER: am335x_pwm
FDT_COMPATIBLE: ti,am335x-pwm

Netbooting ARM/MIPS devices: ubldr

As it was mentioned in previous post U-Boot can boot FreeBSD kernel directly but this approach doesn’t allow a great deal of control over boot process: there is no way to set tunables’ values or pre-load module. Controlling this stuff requires more knowledge of FreeBSD internal data structures and its boot process then U-Boot holds.

On i386 and other Tier1 architectures this task is handled by the loader(8) program. It’s last stage boot loader (e.g. it’s supposed to pass control to FreeBSD kernel only), highly customizable and scriptable. loader(8) relies on one of the previous stages boot loader to access resources like disks, console, network. For i386 it’s BTX and BIOS.

ubldr is implementation of loader(8) for ARM on top of U-Boot. Original code was developed by Semihalf back in 2008 and has been being improved by them and FreeBSD Community since then. Despite it has been around for almost 5 years amount of documentation is shockingly low. I found only these slides from BSDCan 2008.

One of the nice feature U-Boot provides is API for stand-alone process. If you don’t need full-blown operating system running on your hardware but still want access to SD card/network/console you can request them from U-Boot via syscall-like API that turns boot loader into quasi-OS. Some bits of information on this topic can be found in api/README file in U-Boot sources: here.

ubldr uses U-Boot API to enumerate devices that might be used as a boot source: block (e.g. SD card) or network. For network device it will use BOOTP to try to obtain network/boot data and then mount directory over NFS. For block device it will inspect partition table and try to find suitable partition to use as a root device. Once root is mounted ubldr will perform standard loader(8) magic: get loader-related config from /boot/ directory and act on it.

There is no dedicated top-level build target for ubldr so getting it compiled is a little bit tricky. You need to perform whole buildworld cycle before compiling ubldr. Build script would look something like this:

export SRCROOT=/src/FreeBSD/head
export MAKESYSPATH=$SRCROOT/share/mk
export TARGET=arm
export TARGET_ARCH=armv6
export MAKEOBJDIRPREFIX=/src/FreeBSD/obj

make -C $SRCROOT buildworld

buildenv=`make -C $SRCROOT buildenvvars`

eval $buildenv make -C $SRCROOT/sys/boot clean
eval $buildenv make -C $SRCROOT/sys/boot obj
eval $buildenv make -C $SRCROOT/sys/boot UBLDR_LOADADDR=0x2000000 all

Meaning of UBLDR_LOADADDR is the same as KERNPHYSADDR in previous post.

ubldr is ELF executable and can be used with bootelf command. Typical boot log is something like this:

## Starting application at 0x02000054 ...
Consoles: U-Boot console  
Compatible API signature found @7b662a8
Number of U-Boot devices: 2

FreeBSD/armv6 U-Boot loader, Revision 1.2
(gonzo@bsdbox, Fri Apr 19 18:52:33 PDT 2013)
DRAM:    128MB

Device: disk

Device: net

/boot/kernel/kernel data=0x3ae624+0x2128c syms=[0x4+0x71ca0+0x4+0x44075]
Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [/boot/kernel/kernel]...               
Waiting for Ethernet connection... done.
Using DTB provided by U-Boot.
Kernel entry at 0x100100...
Kernel args: (null)
KDB: debugger backends: ddb
KDB: current backend: ddb
Copyright (c) 1992-2013 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.

Netbooting ARM/MIPS devices: kinds of kernel and u-boot

U-Boot is a boot loader. Its task is to get kernel into memory and pass control to it. I will cover only parts of it related to netboot.

kernel or kernel.bin

But before we start loading something we need to know what to load. In previous post I mentioned that there are kernel, kernel.bin, and ubldr files. Let’s get into details. First of all: ubldr requires its own post. So there will be one more covering just ubldr. Now kernel and kernel.bin.

kernel is ELF executable. It means that it’s a self-contained file with all the information required to layout its bits in memory. e.g.: this data in file should be copied to address A, and N bytes at address B should be set to zero, code intry point is address X. All this auxiliary information is stored alongside to raw code and data. U-boot (or any other bootloader) reads it, lays out data/code accordingly and passes control to entry point. U-Boot’s command for it is bootelf.

Now, bootelf or ELF support in general is not always available in boot loaders. In this case we load ELF on host machine. Technically it’s called “convert to binary format” but essentially what objcopy utility does is it simulates loading of ELF file into memory and dumps memory region from the lowest address that belongs to loaded executable to the highest one into the kernel.bin file. No auxiliary information is saved – only raw code and data. Without this information it’s users responsibility to point which address this memory dump should be loaded at and where to start execution.

That’s theory in a nutshell. Back to practice.


Network initialization routine depends on the board you’re working with. If the ethernet card connected to board over USB (like on Raspberry Pi or Pandaboard) you might need to initialize USB first:

U-Boot> usb start
(Re)start USB...
USB0:   Core Release: 2.80a
scanning bus 0 for devices... 3 USB Device(s) found
       scanning usb for storage devices... 0 Storage Device(s) found
       scanning usb for ethernet devices... 1 Ethernet Device(s) found

At this point you can either get network settings via DHCP or set them manually.
Manual control over network is performed by setting U-Boot environment variables:

U-Boot> setenv ipaddr
U-Boot> setenv netmask
U-Boot> setenv gatewayip

DHCP also provides information about TFTP server and boot file, we can set them manually too:

U-Boot> setenv bootfile kernel
U-Boot> setenv serverip

And now load it

U-Boot> tftpboot 0x8000

and boot

U-Boot> bootelf 0x8000

By default tftpboot and bootelf would use loadaddr env variable if it’s set so you can combine last two commands to

U-Boot> setenv loadaddr 0x8000
U-Boot> tftpboot
U-Boot> bootelf

With DHCP everything above is combined into three commands:

U-Boot> setenv loadaddr 0x8000
U-Boot> dhcp
U-Boot> bootelf

If you’re booting ELF loadaddr can be any valid address because bootelf will relocate kernel to proper location. Valid range for addresses depends on the board in use.

With kernel.bin though you have to specify specific value as a loadaddr. Usually it’s KERNPHYSADDR option in kernel config file for ARM and KERNLOADADDR value for MIPS. U-Boot commands sequence would look like:

U-Boot> setenv bootfile kernel.bin
U-Boot> setenv loadaddr 0x00100000
U-Boot> dhcp
U-Boot> go 0x00100000

uImage, ubldr

This is basic stuff I’ve been using for several years in my development environment. There are more options though: u-boot application images and bootm command and ubldr. Former is well-documented on Internet and about latter I’ll post some information soon.

Netbooting ARM/MIPS devices: server setup

I was asked to share details about my root-over-NFS setup so here they are. I decided to split how-to in two posts: server/kernel part and u-boot part.

Usual components in the setup are:

  • DHCP server
  • TFTP server
  • NFS server
  • NAT (optional)

DHCP server

I use net/isc-dhcp42-server as a server. Sample dhcpd.conf:

option root-opts code 130 = string; # NFS / mount options
log-facility local7;

subnet netmask {
        server-name "";
        option subnet-mask;
        option broadcast-address;
        option domain-name-servers;
        option domain-name "";
        option routers;

group {
        host pandaboard {
                hardware ethernet 0E:60:33:B1:46:01;
                filename "kernel.PANDA.bin";
                option root-path "/src/FreeBSD/nfs/armv6";
                option root-opts "nolockd";

        host rpi {
                hardware ethernet b8:27:eb:f6:08:83;
                filename "ubldr";
                option root-path "/src/FreeBSD/nfs/rpi";
                option root-opts "nolockd";

Config is pretty self-explanatory. I use google’s nameserver but you can change it to your very own DNS server. Difference between various filename “…” will be explained later.

dhcpd should be enabled in rc.conf(5)


TFTP server

TFTP server provides access to all files described in filename “…” options so it’s better to keep them together. By default it’s /tftpboot directory but I have whole drive dedicated to FreeBSD development environment and mounted under /src/FreeBSD mountpoint. So I keep everything there and my TFTP server root is /src/FreeBSD/tftpboot. TFTP server is standard FreeBSD’s one and config line in inetd.conf(8) looks like:

tftp    dgram   udp     wait    root    /usr/libexec/tftpd      tftpd -l -s /src/FreeBSD/tftpboot

inted should be enabled in rc.conf(5)


NFS Server

NFS server is not just one daemon but several services combined. So rc.conf(5) part of config looks like this:


Filesystems that are exported via NFS listed in exports(5). Mine contains following:

# Mind mount points obj and nfs are different
/usr/ports -maproot=0 -network
/src/FreeBSD/head /src/FreeBSD/nfs/rpi /src/FreeBSD/nfs/armv6 /src/FreeBSD/nfs/am335x -maproot=0 -network

Note that you can join several directories into one line only if they belong to the same mount point.


If you’re planning on building ports on the device – you’ll need internet access on it. All my devices are restricted to one LAN with laptop acting as a gateway. I use pf(4) for NATing. Config:


nat on $ext_if from $rede to any -> ($ext_if)

and rc.conf(5)



Kernel config

FreeBSD kernel should be properly configured in order to be suitable for mounting root over NFS:

options         NFSCL
options         NFSCLIENT # NFS v3
options         NFS_ROOT
options         BOOTP_NFSROOT
options         BOOTP_COMPAT
options         BOOTP
options         BOOTP_NFSV3
options         BOOTP_WIRED_TO=ue0

BOOTP_WIRED_TO value is SoC-specific. If you do not have full control over your DHCP server (e.g. it’s cable modem) and can’t specify root-path/root-opts you still can hardcode root location by removing BOOTP_NFSROOT and adding

options         ROOTDEVNAME=\"nfs:192.168.10:/src/FreeBSD/nfs/rpi\"


Depending on your boot sequence installation consists of one or two steps.

Normal system installation, e.g.:

sudo -E make TARGET_ARCH=armv6 DESTDIR=/src/FreeBSD/nfs/rpi -DDB_FROM_SRC installworld
sudo -E make TARGET_ARCH=armv6 DESTDIR=/src/FreeBSD/nfs/rpi -DDB_FROM_SRC distribution

And installing kernel copying kernel to tftpboot directory:

sudo -E make TARGET_ARCH=armv6 DESTDIR=/src/FreeBSD/nfs/rpi -DDB_FROM_SRC installkernel
cp /src/FreeBSD/nfs/rpi/boot/kernel/kernel /src/FreeBSD/tftpboot/kernel.RPI 

In some cases you’d want to use kernel.bin instead of kernel (more on it in next post) so second step would look like

sudo -E make TARGET_ARCH=armv6 DESTDIR=/src/FreeBSD/nfs/rpi -DDB_FROM_SRC KERNEL_EXTRA_INSTALL=kernel.bin installkernel
cp /src/FreeBSD/nfs/rpi/boot/kernel/kernel.bin /src/FreeBSD/tftpboot/kernel.RPI.bin

And if you’re going to use ubldr, there is no need to copy installed kernel anywhere.

More details on different types of binaries and boot process in the next post

Netbooting Hackberry A10 (Allwinner A10)

Last few weeks I’ve been acting as a reviewer for Ganbold Tsagaankhuu’s port of FreeBSD for Cubieboard so in order to provide more valuable input and less naysaying I decided to get A10-based device to test his changes. So I ordered Hackberry from I’m not great fan of pushing SD cards back and forth so first thing I do with my SoCs is get them netbooting. That’s where fun begins.

Long story short – I had to get latest official u-boot, merge network driver (sunxi_wemac) from hno’s u-boot and add some GPIO magic to emac initialization. Namely – configure pin H19 (emac_power) as function 1 and set its value to 1. Only then I got net-related commands working properly.

If you’re interested in building your own bootable SD card: fetch these files. uEnv.txt and boot.scr are tailored to my needs so you might want to change them. does all the job, just make sure you use proper device name for SD card.