forked from jappel/VersaMCU
Julian Appel
f60a29137c
Hardware-tested the UF2 bootloader end to end on a real VersaPad v2 board. Found and fixed a real bug: the bootloader's jump into the app (__set_MSP -> SCB->VTOR -> bx) hard-faulted on every standalone boot, even with the debugger fully disconnected; identical register/VTOR values injected directly by a halted debugger ran fine, which pointed at the missing __DSB()/__ISB() barriers ARM's own guidance requires for this exact pattern. Also fixed a USB PID collision (0x0011 is Adafruit's own Gemma M0 bootloader PID, misidentified by Windows as a Circuit Playground COM port instead of exposing VERSABOOT). This board has no dedicated reset/boot button, so add a hardware boot entry that doesn't need one: holding the bottom-right Cherry MX key (key_id 24) during reset/power-on drives its matrix row and reads its column directly in the bootloader, before the app is even validated. Also corrected the app-side flash_with_bootloader.ld (was missing the NVM carve-out flash_without_bootloader.ld already has) and boards/versapad.json (wrong flash/RAM size, wrong MCU macro, stale PID), and enabled the previously-commented-out env:versapad_usb. Documented findings in bootloader/README.md, bootloader/TESTING.md, and doc/09_known_limitations.md. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
29 lines
1 KiB
INI
29 lines
1 KiB
INI
; VersaPad v2 – PlatformIO Configuration
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; Custom SAMD21G17D board (custom PCB)
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; Programmer: Atmel-ICE via SWD (kein Bootloader nötig)
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[common]
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platform = atmelsam
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framework = arduino
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board_build.variants_dir = ${PROJECT_DIR}/variants
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lib_deps = adafruit/Adafruit NeoPixel
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build_flags =
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-DUSB_PRODUCT='"VersaPad v2"'
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-DUSB_MANUFACTURER='"Custom"'
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-DUSB_VID=0x239A
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-DUSB_PID=0x0042
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-DCRYSTALLESS
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; ── Atmel-ICE via SWD (Hauptkonfiguration) ────────────────────────────────────
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[env:versapad]
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extends = common
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board = versapad_nobl
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upload_protocol = custom
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extra_scripts = upload_openocd.py
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debug_tool = openocd
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; ── USB SAM-BA (nur wenn Bootloader geflasht ist) ─────────────────────────────
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[env:versapad_usb]
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extends = common
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board = versapad
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upload_protocol = sam-ba
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