Capability based device driver framework

A computer readable medium comprising computer executable instructions that when executed by one or more processors cause one or more processors to perform the following:

• from a system kernel, assigning I/O resources to the system's root bus;
• from the root bus, assigning a subset of the I/O resources to a device bus, wherein assigning a subset of the I/O resources to a device bus includes limiting the device bus to only be able to assign I/O resources that are assigned to it by the root bus;
• and
• from the device bus, assigning I/O resources to a device through a device interface.

A computing system comprising:

• a plurality of I/O resources
• a system root bus having the plurality of I/O resources assigned to it;
• a device bus having a subset of the I/O resources assigned to the device bus from the root bus, wherein assigning the subset of the I/O resources to the device bus includes limiting the device bus to only be able to assign I/O resources that are assigned to it by the root bus;
• and
• a hardware device having I/O resources assigned to it through a device through a device interface of the device bus.