Determining the level of tests to execute

Each diagnostic application (DA) is responsible for determining the level of tests that can be safely executed. This determination is a function of how the underlying device drivers support access to the device.

Each DA is responsible for determining the level of tests that can be safely executed. This determination is a function of how the underlying device drivers support access to the device.

For nonshared, nonmultiplexed devices, the DA should attempt to open() the device with read/write privileges and thus determine its access privileges. For shared or multiplexed devices, a more complicated strategy needs to be developed. Perhaps the simplest method - at least from an application standpoint - is to add support for an openx() system call to the device driver, where the ext parameter distinguishes between port-level and card-level diagnostics.