Usually I do that via the U-Boot console, since I build my firmware with SPI command support for devices with SPI flash. With an added convenience command, it's just a "==> run mmc-fw-to-sf" to transfer firmware currently running from microSD. So everything is self-contained, no external components involved.

I'd also check that the RDP service is actually running and listening on the expected port. If SSH still works, you can verify the service status and firewall rules from there. That usually helps narrow down whether it's an RDP configuration issue or a network problem.

How do you write U-Boot to SPI NOR flash? Without a working driver upstream, the best I can think of now is just using the shipped U-Boot/Linux (Petitboot from the manufactor). If you want to make it from source, use the shipped cross-compiler on 64 bit PC, perhaps on an archived OS, or rewrite Makefiles. But that leaves the (for some tiny) 16 MB just for the bootloader, which doesn't even knows it's own bootdev. It seems the beforehand bootloader-loader doesn't look after SATA HDD, only SPI NOR or MMC SD. After all, just press a button to alternately load from removable card if one installed and failed to run from NOR. Did I miss a thing in device-tree? The regulator.patch is upstream, which keeps the drives spun-up while boot (at least MMC is powered). Thanks, yours duing.

So.... This is what I've came to with Gemini: /dts-v1/; /plugin/; / { compatible = "allwinner,sun8i-h3"; /* Target the SPI0 controller */ fragment@0 { target = <&spi0>; __overlay__ { status = "okay"; #address-cells = <1>; #size-cells = <0>; /* Disable default spidev to free the bus for the framebuffer */ spidev@0 { status = "disabled"; }; /* PCD8544 LCD Node */ pcd8544@0 { compatible = "philips,pcd8544"; reg = <0>; /* Use SPI Chip Select 0 (PC3) */ spi-max-frequency = <4000000>; /* Max SPI frequency for PCD8544 */ buswidth = <8>; /* Data/Command (DC) Pin Mapping */ /* PA6 -> Port A (0), Pin 6, Active High (0) */ dc-gpios = <&pio 0 6 0>; /* Reset (RST) Pin Mapping */ /* PA9 -> Port A (0), Pin 9, Active High (0) */ reset-gpios = <&pio 0 9 0>; /* Rotate display if needed (e.g., 0, 90, 180, 270) */ rotate = <0>; }; }; }; }; I've got /dev/fb0 to show up this way. Except... It's not usable at all. Can't even print out the console. So there was no point to begin with. What DOES work though, is a Python script using CircuitPython and Blinka: # SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT """ This demo will fill the screen with white, draw a black box on top and then print Hello World! in the center of the display This example is for use on (Linux) computers that are using CPython with Adafruit Blinka to support CircuitPython libraries. CircuitPython does not support PIL/pillow (python imaging library)! """ import board import busio import digitalio from PIL import Image, ImageDraw, ImageFont import adafruit_pcd8544 # Parameters to Change BORDER = 5 FONTSIZE = 10 spi = busio.SPI(board.SCK, MOSI=board.MOSI) dc = digitalio.DigitalInOut(board.PA6) # data/command cs = digitalio.DigitalInOut(board.PC3) # Chip select reset = digitalio.DigitalInOut(board.PA9) # reset display = adafruit_pcd8544.PCD8544(spi, dc, cs, reset) # Contrast and Brightness Settings display.bias = 4 display.contrast = 60 # Turn on the Backlight LED #backlight = digitalio.DigitalInOut(board.D13) # backlight #backlight.switch_to_output() #backlight.value = True # Clear display. display.fill(0) display.show() # Create blank image for drawing. # Make sure to create image with mode '1' for 1-bit color. image = Image.new("1", (display.width, display.height)) # Get drawing object to draw on image. draw = ImageDraw.Draw(image) # Draw a black background draw.rectangle((0, 0, display.width, display.height), outline=255, fill=255) # Draw a smaller inner rectangle draw.rectangle( (BORDER, BORDER, display.width - BORDER - 1, display.height - BORDER - 1), outline=0, fill=0, ) # Load a TTF font. font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", FONTSIZE) # Draw Some Text text = "It's working!" #(font_width, font_height) = font.getsize(text) left, top, right, bottom = font.getbbox(text) font_width, font_height = right - left, bottom - top draw.text( (display.width // 2 - font_width // 2, display.height // 2 - font_height // 2), text, font=font, fill=255, ) # Display image display.image(image) display.show() Using Nokia 5110 LCD library for CircuitPython Using CircuitPython on Orange Pi PC (apparently it's the same for OPi One) Unless /dev/fb0 on this things is even a little bit usable on the LCD, I guess I was running for circles because I was bored I've deleted the overlay altogether since it's probably useless in this case. But I think someone else could benefit from me posting all this here, I don't know. Either way, thank you for leading me along the way!

I'm not gonna explain all that. If you know the exact additions you need in the defconfig, post them here and I'll add them when I do my next PR. Which will probs be sometime this week.