01 PRIVILEGE
Start with the privilege boundary
In Windows, applications run in isolated user-mode processes, while kernel-mode code shares an address space with the operating system and other drivers. Microsoft notes that a faulty kernel driver can damage their data or crash the whole operating system.[1]
That makes isolation a central design question. Before placing logic in the kernel, identify the specific hardware or operating-system capability that requires it and check whether a supported user-mode interface can meet the need.
02 RELEASE
Include shipping and support in the estimate
Driver work continues after implementation. On Windows, signing and installation policies vary with the operating-system version and release target; Microsoft documents separate signing and validation paths for driver packages.[2] Teams should account for the target matrix, release validation, updates, diagnostics and recovery procedures.
Linux has a different maintenance shape: its kernel documentation describes internal driver interfaces as changeable, and distinguishes them from the stable interface used by applications. For an out-of-tree driver, ongoing work may include keeping up with kernel changes.[3]
03 DECISION
A short team checklist
- Necessity: name the requirement that cannot be met at a less privileged layer.
- Failure impact: define how faults will be found, contained and recovered from.
- Operations: list the operating-system versions, architectures, signing, distribution and update work you will support.
04 CALLBACK CONTEXT
What CallBack says about its work
CallBack's current website describes cross-platform developer components intended to help software teams avoid low-level operating-system complexity. It lists virtual filesystems, cloud storage, encryption and file security, synchronization clients, shell features and network monitoring as areas of interest.
This is a summary of the existing site description. It does not confirm support for a particular operating system, language, device or use case.