tockloader: fix address-truthiness bugs around a valid 0x0 - #142
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Several places in the codebase distinguish "no address given/known" from "an address was given/known" using plain truthiness (`if addr:`) on a value that is `None` when unset. That conflates "unset" with an address of exactly `0x0`, which is a normal, valid flash and/or app base address (e.g. any Cortex-M board, or Tock's qemu_arm_mps2 boards). Fix all of these to check `is not None` instead: - `main.py` `command_local_board_set()`: an explicit `--app-address 0x0`/`--flash-address 0x0` was validated but then silently omitted from the status output, making it look like the flag was ignored. - `flash_file.py` `set_local_board()`: the same values were then silently dropped from the persisted `local-board` TOML config, discarding the deliberate setting entirely. - `flash_file.py` `FlashFile.get_flash_address()`: a stored `flash_address == 0` was reported as `None` (unknown) instead of `0`. - `board_interface.py` `BoardInterface.get_apps_start_address()`: a configured `app_address == 0` was ignored in favor of querying the board's `appaddr` attribute (or returning `None` if that's absent). - `tockloader.py` `_get_apps_start_address()`: a cached value of `0`, an explicit `--app-address 0x0` on any command (not just `local-board set`), or a channel-reported address of `0` were all treated as "unknown" and silently overridden by lower-priority defaults. - `tockloader.py` `_get_flash_start_address()`: a channel-reported flash address of `0` was treated as "unknown" and replaced with the function's own hardcoded `0` default -- harmless today only because that default happens to also be `0`. - `tockloader.py` `_get_memory_start_address()`: same cached-value pattern as above, for the app RAM start address. Verified with `local-board set zerotest --arch cortex-m3 --app-address 0x0 --flash-address 0x0`: both values now appear in the status output and are correctly persisted as `0` (not omitted) in the TOML config. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KTQ6pWrckM3jp9vfBo4bhk
bradjc
approved these changes
Sep 2, 2026
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Update
ifchecks around addresses to explicitly compare toNone, so that an address of0x0doesn't accidentally evaluate asFalse.Claude's essay
Several places in the codebase distinguish "no address given/known" from "an address was given/known" using plain truthiness (
if addr:) on a value that isNonewhen unset. That conflates "unset" with an address of exactly0x0, which is a normal, valid flash and/or app base address (e.g. any Cortex-M board, or Tock's qemu_arm_mps2 boards). Fix all of these to checkis not Noneinstead:main.pycommand_local_board_set(): an explicit--app-address 0x0/--flash-address 0x0was validated but then silently omitted from the status output, making it look like the flag was ignored.flash_file.pyset_local_board(): the same values were then silently dropped from the persistedlocal-boardTOML config, discarding the deliberate setting entirely.flash_file.pyFlashFile.get_flash_address(): a storedflash_address == 0was reported asNone(unknown) instead of0.board_interface.pyBoardInterface.get_apps_start_address(): a configuredapp_address == 0was ignored in favor of querying the board'sappaddrattribute (or returningNoneif that's absent).tockloader.py_get_apps_start_address(): a cached value of0, an explicit--app-address 0x0on any command (not justlocal-board set), or a channel-reported address of0were all treated as "unknown" and silently overridden by lower-priority defaults.tockloader.py_get_flash_start_address(): a channel-reported flash address of0was treated as "unknown" and replaced with the function's own hardcoded0default -- harmless today only because that default happens to also be0.tockloader.py_get_memory_start_address(): same cached-value pattern as above, for the app RAM start address.Verified with
local-board set zerotest --arch cortex-m3 --app-address 0x0 --flash-address 0x0: both values now appear in the status output and are correctly persisted as0(not omitted) in the TOML config.Claude-Session: https://claude.ai/code/session_01KTQ6pWrckM3jp9vfBo4bhk