# Turning on HDMI video after boot



## mallniya (Jan 11, 2017)

Hello forum,

there is a problem with absence of signal when I try to connect an HDMI cable to my Intel NUC after it boots. When cable there in the first place -- it works.

Research shows that I'm not alone with this:
https://lists.freebsd.org/pipermail/freebsd-arm/2016-March/013575.html

Considering diff of /var/run/dmesg.boot without and with cable:


```
VT(vga): resolution 640x480                                   | VT(efifb): resolution 1920x1200
SMP: AP CPU #2 Launched!                                      <
Timecounter "TSC" frequency 1800070777 Hz quality 1000        | SMP: AP CPU #2 Launched!
                                                              > Timecounter "TSC" frequency 1800066298 Hz quality 1000
                                                              > ugen0.2: <vendor 0x0424 product 0x2514> at usbus0
                                                              > uhub1 on uhub0
                                                              > uhub1: <vendor 0x0424 product 0x2514, class 9/0, rev 2.00/b.b
                                                              > uhub1: MTT enabled
                                                              > uhub1: 4 ports with 4 removable, self powered
                                                              > Root mount waiting for: usbus0
                                                              > ugen0.3: <vendor 0x1a40 USB 2.0 Hub MTT> at usbus0
                                                              > uhub2 on uhub1
                                                              > uhub2: <vendor 0x1a40 USB 2.0 Hub MTT, class 9/0, rev 2.00/1.
                                                              > uhub2: MTT enabled
                                                              > uhub2: 4 ports with 4 removable, self powered
                                                              > Root mount waiting for: usbus0
                                                              > ugen0.4: <SIGMACHIP USB Keyboard> at usbus0
                                                              > ukbd0 on uhub2
                                                              > ukbd0: <SIGMACHIP USB Keyboard, class 0/0, rev 1.10/1.10, add
                                                              > kbd1 at ukbd0
                                                              > Root mount waiting for: usbus0
                                                              > ugen0.5: <A4TECH USB Device> at usbus0
                                                              > ukbd1 on uhub1
                                                              > ukbd1: <A4TECH USB Device, class 0/0, rev 1.10/1.91, addr 4>
                                                              > kbd2 at ukbd1
                                                              > uhid0 on uhub2
                                                              > uhid0: <SIGMACHIP USB Keyboard, class 0/0, rev 1.10/1.10, add
                                                              > ums0 on uhub1
                                                              > ums0: <A4TECH USB Device, class 0/0, rev 1.10/1.91, addr 4> o
                                                              > ums0: 16 buttons and [XYZT] coordinates ID=0
```

especially first line -- I would guess that if I can tweak efifb driver of VT instead of vga by force at boot time that will help.

Any thoughts? Thanks in advance.


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## aragats (Jan 12, 2017)

mallniya said:


> Research shows that I'm not alone with this


The post you refer to is about Raspberry Pi, it's completely different hardware (there is a known solution for that in Linux, not sure about FreeBSD).

In your case it's Intel HD Graphics 4000 (Ivy Bridge CPU), and it's supported by FreeBSD as per https://wiki.freebsd.org/Graphics.
Do you have in your /boot/loader.conf

```
i915kms_load="YES"
```


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## horseflesh (Jan 13, 2017)

Search led me to this thread, same problem: the display on Intel HD Graphics works fine if connected at boot, but if not, the display will not work.

I have a 3315u CPU, which is Broadwell. The chart on the wiki shows that it is not yet supported but it's clearly backwards compatible enough to operate with the Haswell driver.

Would it be better to put the directive in /boot/loader.conf or in /etc/rc.conf as _kld_list="i915kms"_ ?

Edit to add: I verified that loading the module in rc.conf does work for this Broadwell CPU. An HDMI monitor can now be attached after boot with success.


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## mallniya (Jan 14, 2017)

aragats, no HD Graphics 4000 in my NUCm it's Iris: http://www.intel.com/content/www/us/en/nuc/nuc-kit-nuc6i5syh.html
Also not sure i915kms is required, because there is no i915kms while `kldstat` from console with an HDMI.


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