Pine64

https://pine64.com/product-category/quartz64/ reviewed at https://www.youtube.com/watch?v=edBU1h9S4dM $59 The Quartz64 model A SBC featuring the Rockchip RK3566 SoC. This SoC combines a quad-core, ARM Cortex-A55 CPU with a Mali-G52-2EE GPU. It is capable of driving a single 4K display at 60fps and the GPU uses the open source Panfrost driver. It also has the benefit of running very cool, even without a heatsink and under a sustained load. This SBC is equipped with 4GB LPDDR4 system memory, an optional eMMC module (up to 128GB) and microSD slot for booting. The board is equipped with a PCIe x1 open ended slot, 1x USB 3.0 type C Host share with 1x SATA 3.0 port, 3x USB 2.0 Host, Gigabit Ethernet, MiPi DSI interface, e-ink interface, eDP interface, touch Panel interface, MiPi CSI interface, as well as many other peripheral device interface such as UART, SPI, I2C, for makers to integrate with sensors and other peripherals.
=== sbc mipi ===
https://pine64.com/product/128mb-ox64-sbc-available-on-december-2-2022/ 128Mb Ox64 SBC , $8.00' The Ox64 Single Board Computer features a Bouffalo Lab BL808 RISC-V SoC with single 64-bit 480MHz RV64 C906 core and two 32-bit 320MHz RV32 E907 + 150MHz E902 cores, 728KB internal SRAM and 64MB internal PSRAM. This Ox64 is equipped with 128Mb (16MB) XSPI Flash, and micro-SD card slot. It is also equipped with 802.11 b/g/n Wifi, BLE 5.0 and Zigbee radios. A breadboard friendly form factor with wide range of GPIO includes USB, UART, I2C, SPI, ADC, DAC, MII (Ethernet), I2S (Audio) and MiPi-CSI Ports. The Ox64 is an affordable, simple, and versatile platform that will serve PINE64 community for years to come, also as a basis for maker type PINE64 devices support endless possible DIY applications. The 128Mb Ox64 SBC suitable for both Linux and RTOS development.
=== @MyGeekyHobby ===
https://www.youtube.com/watch?v=vPAk5sq_Ilc The video shows Pine64 Ox64 Single Board Computer. It also covers the basics of installing the firmware, loading, and booting Linux os. 
Pico firmware to support two serial ports is here: 
https://github.com/Kris-Sekula/Pine64_Ox64_SBC/tree/main/uart 
Flashing Instructions: 
https://github.com/openbouffalo/buildroot_bouffalo/releases 
Flashing software: 
https://dev.bouffalolab.com/download 
Other useful software: 
https://www.balena.io/etcher 
https://www.7-zip.org/ 
=== links ===
raspberry
risc