# QMI APDU Backend

QMI is a proprietary protocol used by Qualcomm devices.
It is commonly used for communication with cellular modems.

## OpenWrt Specific

On OpenWrt, the `uqmi` command line tool can be used to interact with QMI devices.

To use `uqmi` as the APDU backend, set the `LPAC_APDU` environment variable to `uqmi`.

## Environment Variables

- `LPAC_APDU_QMI_UIM_SLOT`: specify which UIM slot to use. \
  ([integer](types.md#integer-type), default: `1`, slot number starts from `1`)
- `LPAC_APDU_QMI_DEVICE`: specify the QMI device path. \
  ([string](types.md#string-type), default: `/dev/cdc-wdm0`)
- `LPAC_APDU_UQMI_DEBUG`: enable debug output for `uqmi` commands. \
  ([boolean](types.md#boolean-type), default: `false`)
- `LPAC_APDU_UQMI_PROGRAM`: specify the `uqmi` program path. \
  ([string](types.md#string-type), default: `uqmi`)