The Zidoo X9S is a TV box, shipping with Android pre-installed.
- Realtek RTD1295 SoC
- 4x ARM Cortex-A53 CPU
- ARM Mali-T820 MP3 GPU
- 2 GB RAM
- 16 GB eMMC
- Micro SD slot
- 2x USB 2.0, 1x USB 3.0
- 1x 1 Gb Ethernet
- Realtek RTL8821AU Wifi module
- 1x HDMI out, 1x HDMI in
- SPDIF, AV out
The bottom plate can easily be unscrewed.
A male 2 mm connector is available below the board, between USB 3.0 and SATA connectors; the pins are also accessible from the top. Hints on which female connector to use welcome!
With a standard 0.1" TTL UART USB adapter, RX and TX can be plugged inside the connector and for space reasons GND elsewhere (e.g., via male-male cable to the USB connector in the corner).
The device first boots into a v2012.07 based AArch32 U-Boot. To get to a prompt, press space or ESC.
The default boot command, bootr, boots into a v2015.07 based AArch64 U-Boot with no timeout for pressing a key.
To get to a prompt in the second U-Boot, you can instead enter b2ndbc at the prompt of the first U-Boot.
tftp $kernel_loadaddr uImage tftp $fdt_loadaddr rtd1295-zidoo-x9s.dtb tftp $rootfs_loadaddr initrd.cpio.gz fdt addr $fdt_loadaddr fdt resize env set bootcmd "" b2ndbc
Following that in aarch64 U-Boot:
setenv bootargs "earlycon initrd=$rootfs_loadaddr,0x$filesize" bootm $kernel_loadaddr - $fdt_loadaddr
The uImage must use 0x00280000 as load address, or the Image needs to be built with patched
TEXT_OFFSET (default: 0x80000) to boot successfully.
Mainline U-Boot does not yet contain support for this SoC or device.
The v4.13-rc1 kernel added initial support for this SoC and device, but needs additional DT tweaks to get serial working beyond earlycon.