Socram

@Socram Hello, it's definitely an rk322x. Despite the kernel is the same for rk322x and rk3288, the socs are profoundly different and so are the device trees. An image for rk322x would not boot on rk3288 and viceversa.
 
Anyway, you should run rk322x-config and use the appropriate led-conf for your board. AFAIR you should have two options: led-conf8 for h20 boards with two voltage regulators (better, looking at the board photos this should fit) and led-conf7 with r29/r2b/h20 boards with single voltage regulator (worse but more compatible).
 
You may go with led-conf8 first, see if it is stable under load. If not, go with led-conf7. Both the configs should make HDMI work

You're right! It's a RK3288. I thought it was a RK3228A because that's what the vendor advertised.
 
I realized the thing was actually replying to pings, removed the MicroSD, chrooted into the machine and created an user and enabled ssh, connected to it and sure enough:
[ 9.831684] rk3288-crypto 100a0000.cypto-controller: will run requests pump with realtime priority [ 9.831930] rk3288-crypto 100a0000.cypto-controller: Register ecb(aes) as ecb-aes-rk [ 9.832042] rk3288-crypto 100a0000.cypto-controller: Register cbc(aes) as cbc-aes-rk [ 9.832082] rk3288-crypto 100a0000.cypto-controller: Register ecb(des) as ecb-des-rk [ 9.832112] rk3288-crypto 100a0000.cypto-controller: Register cbc(des) as cbc-des-rk [ 9.832139] rk3288-crypto 100a0000.cypto-controller: Register ecb(des3_ede) as ecb-des3-ede-rk [ 9.832170] rk3288-crypto 100a0000.cypto-controller: Register cbc(des3_ede) as cbc-des3-ede-rk [ 9.832199] rk3288-crypto 100a0000.cypto-controller: Register sha1 as rk-sha1 [ 9.832232] rk3288-crypto 100a0000.cypto-controller: Register sha256 as rk-sha256 [ 9.832261] rk3288-crypto 100a0000.cypto-controller: Register md5 as rk-md5 I do see RK3288 references. Thanks for the tip!
armbian-hardware-monitor.zip
 
EDIT: No, I think this is actually a RK3229 based on the DTS. I also opened the device and, while I cannot read the specific part number because it is hidden under the heatsink, it's a plastic IC so it cannot be a RK3288 which was sold in a metal BGA package.
 
An except from the multitool dmesg log regarding the DRM:
[ 2.648953] [drm] Initialized drm 1.1.0 20060810 [ 2.656047] [drm] Rockchip DRM driver version: v1.0.1 [ 2.661464] rockchip-drm display-subsystem: devfreq is not set [ 2.668188] rockchip-drm display-subsystem: bound 20050000.vop (ops 0xb0d05b78) [ 2.676005] i2c i2c-0: of_i2c: modalias failure on /hdmi@200a0000/ports [ 2.682689] dwhdmi-rockchip 200a0000.hdmi: registered DesignWare HDMI I2C bus driver [ 2.690553] dwhdmi-rockchip 200a0000.hdmi: Detected HDMI TX controller v2.01a with HDCP (inno_dw_hdmi_phy) [ 2.701808] rockchip-drm display-subsystem: bound 200a0000.hdmi (ops 0xb0cfe0d8) [ 2.709310] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). [ 2.715950] [drm] No driver support for vblank timestamp query. [ 2.722040] rockchip-drm display-subsystem: failed to parse display resources [ 3.353464] rockchip-vop 20050000.vop: [drm:vop_crtc_enable] Update mode to 1920x1080p60, type: 11 [ 3.354145] dwhdmi-rockchip 200a0000.hdmi: HDMI infoframe: Auxiliary Video Information (AVI), version 2, length 13 [ 3.354154] dwhdmi-rockchip 200a0000.hdmi: colorspace: RGB [ 3.354161] dwhdmi-rockchip 200a0000.hdmi: scan mode: Underscan [ 3.354168] dwhdmi-rockchip 200a0000.hdmi: colorimetry: No Data [ 3.354174] dwhdmi-rockchip 200a0000.hdmi: picture aspect: 16:9 [ 3.354181] dwhdmi-rockchip 200a0000.hdmi: active aspect: Same as Picture [ 3.354188] dwhdmi-rockchip 200a0000.hdmi: itc: IT Content [ 3.354194] dwhdmi-rockchip 200a0000.hdmi: extended colorimetry: xvYCC 601 [ 3.354202] dwhdmi-rockchip 200a0000.hdmi: quantization range: Full [ 3.354209] dwhdmi-rockchip 200a0000.hdmi: nups: Unknown Non-uniform Scaling [ 3.354216] dwhdmi-rockchip 200a0000.hdmi: video code: 16 [ 3.354223] dwhdmi-rockchip 200a0000.hdmi: ycc quantization range: Full [ 3.354230] dwhdmi-rockchip 200a0000.hdmi: hdmi content type: Graphics [ 3.354236] dwhdmi-rockchip 200a0000.hdmi: pixel repeat: 0 [ 3.354245] dwhdmi-rockchip 200a0000.hdmi: bar top 0, bottom 0, left 0, right 0 [ 3.430974] Console: switching to colour frame buffer device 240x67 [ 3.598766] rockchip-drm display-subsystem: fb0: frame buffer device In the case of the latest version of Armbian:
[ 1.557514] inno-hdmi-phy 12030000.hdmi-phy: error -ENXIO: IRQ index 0 not found [ 1.558040] inno-hdmi-phy 12030000.hdmi-phy: phy_flag is: 0 [ 1.560579] rockchip-drm display-subsystem: bound 20050000.vop (ops 0xb1179c70) [ 1.560740] dwhdmi-rockchip 200a0000.hdmi: supply avdd-0v9 not found, using dummy regulator [ 1.561045] dwhdmi-rockchip 200a0000.hdmi: supply avdd-1v8 not found, using dummy regulator [ 1.561515] dwhdmi-rockchip 200a0000.hdmi: Detected HDMI TX controller v2.01a with HDCP (inno_dw_hdmi_phy2) [ 1.563057] dwhdmi-rockchip 200a0000.hdmi: registered DesignWare HDMI I2C bus driver [ 1.563492] rockchip-drm display-subsystem: bound 200a0000.hdmi (ops 0xb117d958) [ 1.564699] [drm] Initialized rockchip 1.0.0 20140818 for display-subsystem on minor 0 [ 1.564912] rockchip-drm display-subsystem: [drm] Cannot find any crtc or sizes [ 1.565125] rockchip-drm display-subsystem: [drm] Cannot find any crtc or sizes Seems it is unable to find the CRTC?
device-dtb-and-dts.zip multitool-dmesg.zip
 
EDIT 2: I can guarantee 100% this is a RK3228. Reading the eFuses:
root@multitool:~# cat /sys/bus/nvmem/devices/rockchip-efuse0/nvmem | od -tx1 -An 52 4b 23 82 81 f0 70 55 52 4b 58 32 32 30 33 33 00 00 00 00 0c 0e 26 05 00 04 01 00 00 78 00 00 Note bytes 0x02 and 0x03 are 0x23 0x82, which indicate a RK3228