v2.3 USB Mass Storage and No-Flash/RAM-only apps

Plug your Pico into your PC after(*) entering the menu, and the SD card will show up as a flash drive!

Apps compiled with the pico-sdk no-flash attribute will be run directly from RAM without affecting the app loaded into the flash. Good for small utilities!

Both the bootloader and the UI need to be installed when upgrading to this version.

(* Not kidding, start the menu before inserting the cable, or things will not work. You have been warned!)

V2.2 - minor fixes, diagnostic tool

Just bundling a few minor tweaks that have been waiting on the main branch for a while.

Since the bootloader can't show a useful message if something is wrong, I've also added a simple diagnostic tool.

If you can't get the bootloader menu to show up, flashing and running this tool should show you what is wrong. All steps need to show "PASS" for the bootloader to be able to bring up the menu.

V2.1 - Bugfixes, improvements

Entering the menu can now be done by holding F1 or F5 in addition to the existing Up, whichever is more convenient. (BOOTSEL is now also on F3.) The keyboard routine is also more robust and less likely to misinterpret a bad keypress.

The low level SD card driver has been replaced, so cards other than the Lexar that comes with the PicoCalc should now work as well.

The bootloader drops into BOOTSEL instead of the application when the menu is requested but it fails to load. At least it will make it clearer when something is wrong.

Error messages for UF2s that are bad or for the wrong platform are improved. It will also stay in the menu instead of automatically rebooting, so another option can be selected.

Ejecting and reinserting the SD card while in the menu should now work properly instead of throwing an error and rebooting.

Pico 2 support!

UF2 Loader now supports both pico 1 and pico 2 boards (and W versions).

Copy BOOT2040.uf2 and BOOT2350.uf2 to the SD card, put any UF2 apps in the pico1-apps and pico2-apps folders as desired, and flash the appropriate bootloader_*.uf2 to your board.

Minor revision v1.1

Added the ability for an application to detect the bootloader by reading the 8 bytes at the very end of the flash area.

UF2 loader initial release

Initial release with transparent UF2 support for Pico 1