Files
PX4-Autopilot/docs/en/dronecan
Jacob Dahl 0524a374d9 fix(drivers/uavcannode): make CANNODE_NODE_ID the sole node ID policy (#27644)
* fix(drivers/uavcannode): make CANNODE_NODE_ID the sole node ID policy

The startup bootloader_app_shared_write() never reached the bootloader:
it only accepts App-signed data and invalidates the shared region on
every boot. The only consumer was uavcannode itself on a restart
without a reset (nsh stop/start), where the persisted bus_speed=0 made
the CAN driver init fail and left the node off the bus. The bootloader
learns our node ID exclusively through the firmware update handoff in
cb_beginfirmware_update, which already carries the static ID.

CANNODE_NODE_ID now overrides the bootloader handoff only when nonzero,
so the default (0) reuses the ID the bootloader already allocated
instead of running allocation a second time. The handoff is ignored
unless it carries a valid bitrate, healing regions poisoned by firmware
that wrote bus_speed=0. Max is 125 because 126/127 are reserved for
debug tools by DroneCAN convention, matching UAVCAN_NODE_ID.

Signed-off-by: Jacob Dahl <dahl.jakejacob@gmail.com>

* fix(drivers/uavcannode): harden bootloader handoff validation

Invalidate the shared region whenever it was read valid, not only when
the handoff is accepted, so stale data cannot linger on boards whose
bootloader never invalidates it. Require a plausible bitrate (the
CANNODE_BITRATE minimum) rather than nonzero: the canbootloader alt-app
update path can hand off bus_speed = CAN_UNDEFINED (999). Reword the
invalid-param error, which claimed dynamic allocation while keeping the
bootloader handoff.

Signed-off-by: Jacob Dahl <dahl.jakejacob@gmail.com>

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Signed-off-by: Jacob Dahl <dahl.jakejacob@gmail.com>
2026-07-16 20:43:22 -06:00
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