Can pico be used as boot/bios keyboard?

[shuangg]

I tested under bois and it is not working

[ndt1896]

I also am curious about using the pico keyboard under BIOS/Boot menus.
Testing with the keyboard example directly from TinyUSB, I also had no luck: https://github.com/hathach/tinyusb/tree/master/examples/device/hid_composite/src

Tired on different laptops, desktops, and even rack-mount servers - no luck on any host. I wonder what it is about TinyUSB that makes it not work with BIOS usb drivers.

[guruthree]

It seems like proper USB keyboards have a special mode of some sort needed to work in the BIOS. From NicoHood/HID#34 it looks like the way the USB keyboard HID device is created needs to be adjusted along with some slight modification of USB reports.

I think this is controlled in TinyUSB via the TUD_HID_DESCRIPTOR call. Following the code back then it looks like in https://github.com/adafruit/Adafruit_TinyUSB_Arduino boot protocol support can be enabled via Adafruit_USBD_HID::setBootProtocol(true).

I think the code modification to enable this in pico-superkey-board would therefore be

diff --git a/pico-superkey-board.cpp b/pico-superkey-board.cpp
index b358495..5915abf 100644
--- a/pico-superkey-board.cpp
+++ b/pico-superkey-board.cpp
@@ -47,12 +47,14 @@ static bool loopTask(repeating_timer_t *rt){
 
 // Adafruit TinyUSB instance
 extern Adafruit_USBD_Device USBDevice;
+extern Adafruit_USBD_HID usb_hid;
 
 int main() {
     bi_decl(bi_program_description("A single superkey keyboard"));
     bi_decl(bi_program_feature("USB HID Device"));
 
     board_init(); // Sets up the onboard LED as an output
+    usb_hid.setBootProtocol(true);
     USBDevice.begin(); // Initialise Adafruit TinyUSB
 
     // Timer for regularly processing USB events
lines 1-19/19 (END)

but I don't have a good way of testing this right now.

[yohanes]

but I don't have a good way of testing this right now.

I can confirm that this small patch works, and I used this when setting up laptops for https://ioi2022.id/.

We needed to change a BIOS/UEFI setting: we wanted the F1-F12 key to act as function keys instead of media keys (which is the default on the laptops we got). We couldn't find any tool to change this setting, so I used this project to automate the change by sending a sequence of keys.

Thank you for this project.