[Keyboard] Add yr6095

[jiaxin96]

Description

Add yr6095 keyboard.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[sigprof]

@jiaxin96 This PR specifies the bootloader for the yandrstudio/yr6095 keyboard as stm32duino; however, boards recently purchased from https://www.aliexpress.us/item/3256804503651503.html apparently come with the uf2boot bootloader, therefore the firmware built from this code is not compatible with those PCBs.

Would you please prepare a PR to add support for the new revision of YR6095 PCBs with the uf2boot bootloader? Note that if any boards sold earlier were using the stm32duino bootloader, a new PCB revision will need to be added instead of just changing the bootloader type in place, so that any users of the older PCBs would still be able to build the firmware suitable for their boards.

[jiaxin96]

@jiaxin96 This PR specifies the bootloader for the yandrstudio/yr6095 keyboard as stm32duino; however, boards recently purchased from https://www.aliexpress.us/item/3256804503651503.html apparently come with the uf2boot bootloader, therefore the firmware built from this code is not compatible with those PCBs.

Would you please prepare a PR to add support for the new revision of YR6095 PCBs with the uf2boot bootloader? Note that if any boards sold earlier were using the stm32duino bootloader, a new PCB revision will need to be added instead of just changing the bootloader type in place, so that any users of the older PCBs would still be able to build the firmware suitable for their boards.

You can try to use the production branch of Y&R to build the firmware of YR6095 keyboard. Since the master branch of qmk upstream merged the uf2boot for stm32f103 just recently, and Y&R Studio used the modified uf2boot BootLoader of uf2boot for awhile now, so the code based on stm32duino was submitted to the master branch of QMK upstream first, and the precompiled Y&R uf2boot is here.

[sigprof]

@jiaxin96 Thanks for a fast answer.

Are the sources of that modified uf2boot bootloader available somewhere? I poked at the 8 MHz version that I could run on a bluepill, and apparently that bootloader uses a different RAM location for the bootloader command (0x20004ffc instead of 0x20004000), and also a different magic value to force entering the bootloader (0xF01669EF instead of 0x544F4F42). Because of those changes, the code for BOOTLOADER = uf2boot that is present in the recent QMK firmware won't work for your modified uf2boot version; however, the magic value is actually identical to the one used by the tinyuf2 bootloader, so BOOTLOADER = tinyuf2 may work after adding an appropriate .ld file which sets the address for _board_dfu_dbl_tap.

Also apparently the only way to force entering the bootloader if some firmware is present in the flash is to set that 0xF01669EF magic value from the firmware; this leaves the user without any simple way to recover the board after flashing a wrong firmware by mistake. Or is there any hidden way to trigger the bootloader even when the firmware does not work? Apparently the double tap reset support is not enabled in your bootloader.

[jiaxin96]

Regarding the adjustment items of BL, you can look at this repo. yr6095 uses a 16mhz crystal oscillator, and you need to pay attention to this when compiling and flashing firmware.