I'm trying to read a push button on the 40-pin HAT of a UP Squared Pro 7000 (UPN-ADLN01) under Windows. The signal is correct on the pin (confirmed with a multimeter), but no software layer ever sees it change. The same C# code worked on another UP board (UP Xtreme i14).

Setup

• Board: UPN-ADLN01, BIOS [BIOS version]
• OS: Win 11 IOT, 64-bit
• UP Framework 24.09.10 (clean install; drivers: ACPI 11.5.15.822, Service 11.5.15.822, LED 11.6.14.247)
• BIOS HAT configuration: the pin is set to GPIO, direction Input

Circuit (active-high)

• Pin 1 (3.3V) -> button -> pin 7
• 10kΩ from pin 7 -> pin 9 (GND)
• Multimeter on pin 7: ~0V released, ~3.3V pressed. Also tried pin 15 with the same result.

What I've tested (all read-only while pressing the button)
1. EAPI directly (aaeonEAPI.dll, EApiGPIOGetLevel) polling all IDs 0–39, using ID = physical pin − 1. No ID changes on press.
2. UpNetlib UPGpioProvider + Windows.Devices.Gpio (.NET), opening physical pin − 1 as Input. Level never changes. InputPullUp is rejected with "Only support Output or Input Mode".
3. AAEON's UpNetGpioTestTool from win-demo-apps: pin 6 (= physical 7) reads Low, including while the button is held.

Software vs meter doesn't match on other pins either:

• Pin 29: software HIGH, meter 0.01V
• Pin 7 (button held): software LOW, meter 3.3V

The mapping itself looks right: EApiGPIOGetDirection fails only on the alt-function pins (3, 5, 8, 10, 11, 19, 21, 23, 24, 27, 28), which matches the header layout. So it looks like the header side isn't being passed through to the SoC for inputs.

I also cleaned up a mixed SDK install (24.09.10 and 24.12.27 had been installed over each other, and the 24.12.27 ACPI driver was left behind). The behaviour is the same on the clean 24.09.10 stack.

I found the linux-gpio thread "Up Squared Pro 7000 (UPN-ADLN01) broken BIOS?", where HAT pins were owned by ACPI/locked by the BIOS, and AAEON shared an engineering BIOS (UNASAM36) that fixed inputs on Linux.

Questions
1. Is this the same BIOS issue, and does that fix also apply to Windows?
3. Is there any other BIOS setting needed beyond GPIO + Input for the pin?
4. Which UP Framework version is recommended for this board? 24.09.10 doesn't include UpNetlib.dll, while 24.12.27 did.
5. Any recommendations in general?

Happy to run any tests or send logs. Thanks!

On the 7000 Pro, the x7425E's UART0 appears to be the one connected to pins 8 and 10 on the 40-pin header. I'm not really looking to use this as a general-purpose COM port like many of the answers I've been finding here and on the Wiki. Rather, I'm using the 7000 Pro to prototype firmware that will eventually run on a custom board that will have one of the SoC UARTs permanently wired to an on-board custom ASIC. That resource will be shared among multiple applications, and the framework of a UMDF2 or KMDF driver is perfectly suited to managing that.

While I have some Windows driver experience, I'm new to both ACPI and SerCx2.

After going into the BIOS CRB Setup > CRB Chipset > PCH-IO Configuration, enabling UART0 in ISH Configuration, and setting the UART0 Controller to "Communication Port (COM)" in SerialIo Configuration, and uninstalling the Intel UART controller driver (iaLPSS2_UART2_ADL_N.sys), I have both Mincomm and PuTTY able to echo characters through COM3 (alias "\?\ACPI#PNP0501#SERIALIOUART0#{86e0d1e0-8089-11d0-9ce4-08003e301f73}"). It looks like the system is well equipped for my development needs.

So, with Microsoft's SerCx2, I think the basic idea will be to change the UART0 Controller to simply "Enabled" and install Intel's UART controller driver, which I believe fulfills the controller part of the SerCx2 architecture, plugging into the SerCx2 framework that provides the API my peripheral driver will use.

As I understand it, I need to add a Device object in ACPI to represent the custom ASIC, and the hardware ID I declare there (_HID) is what I'll place in my driver's INF file to get it loaded when Windows starts.

The part eluding me at the moment is how to write my Device object's ASL to link the appropriate object representing UART0. The custom ASIC should look to Windows like a fixed non-PnP device attached through a UartSerialBus, I think.

Which object do I need to link to (\\_SB.PC00.UA00, maybe?) and what and how do I express this connection in ASL?

Thank you in advance.

F.