[IPP] RFC: Printer Firmware Updates via IPP System Service

All,

During our last call review of the IPP System Service v1.0, several questions came up concerning how firmware updates will be applied once the resource is created, uploaded (sent), and installed.  The consensus was to add a subsection 17.x (Appendix A - Rationale for Design Choices) documenting how we see this working without defining/requiring a particular file format.  The following is my proposed text for this subsection:

17.4 Executable Resources

This specification defines two types of executable resources: firmware ('executable-firmware') and application software ('executable-software').  While no specific file format has been mandated, an executable resource file:

- Provides a manifest providing descriptive text, version number(s), subunit or other associations, and a cryptographic hash of the executable content,
- Provides a cryptographic signature of the metadata, and
- Contains the executable content.

When subunit firmware is installed (or queued for installation on the next restart of the System), it applies to all compatible subunits.  For example, if a System contains multiple fold finishers and an Administrator installs new fold finisher firmware, all of the fold finishers are updated - there is no way to selectively upgrade a single subunit.

When application software is installed, it typically applies to the System and all of its Printers.  However, this specification does not prohibit applications that need to be subsequently allocated to a Printer, for example a cloud-based PDF interpreter application could be installed and later allocated to a specific Printer.

Please provide your feedback before the next IPP workgroup conference call on October 24, 2019 so that we can start a PWG Formal Vote to span the November face-to-face meeting.

________________________
Michael Sweet