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FBOSS BSP Mapping

A platform's BSP mapping is derived directly from its platform_manager.json (fboss/platform/configs/PLATFORM/platform_manager.json).

The same configuration that PlatformManager uses to create the transceiver and LED device nodes is also the single source of the BSP mapping consumed by qsfp_service and led_service. There is no separate BSP mapping input to maintain.

For example, the lanesPerPort field on a port's LED control block, together with ledPerPort, lets the lane-to-LED mapping be derived directly from platform_manager.json: the port's lanes are distributed evenly across its LEDs, so a port with lanesPerPort: 8 and ledPerPort: 2 maps lanes 1–4 to the first LED and lanes 5–8 to the second.

Transceiver access paths​

For each transceiver N, PlatformManager creates a consistent set of device nodes under /run/devmap/xcvrs/, all keyed off the transceiver id — so transceiver N always uses index N, with no per-platform translation table:

  • xcvr_io_N — I2C data path to the module; qsfp_service uses it to read/write the module memory map (EEPROM/ID, DOM, registers, config).
  • xcvr_ctrl_N — control node exposing xcvr_reset_N (reset) and xcvr_present_N (presence detect).