Hello,
On 08.12.18 23:05, John J. Karcher wrote:
In my slow quest to port/write the VirtualBox Guest Additions, the first step is a driver for the virtual PCI device that handles communication with the VirtualBox host.
Is there a skeleton device driver for PCI devices? My first goal is just the boilerplate init code, attaching to the IRQ and I/O memory, and logging the interrupts as they come in.
If there isn't a skeleton driver, could anyone recommend the simplest example that I could use as a starting point?
I would suggest look into [0] and [1], which is a very very basic test to iterate over all available PCI devices and dumping some PCI information ([3] or better look into the Genode Foundations Book). The test may serve as a starting point.
Which devices are actually available/visible to a driver depend on the configuration of the platform driver, which acts as an PCI guard. Please look into [2] for configuration details.
When you have found/chosen your specific PCI device, you can invoke several methods on a Platform::Device_client [4] object as used in the test, which give you access to various PCI resources in form of capabilities, like IRQ, IO-PORT or IO-MEM resources.
Please consult the Genode Foundations book for a basic introduction and documentation - e.g. 3.4.7. Access to device resources, 4.1.1 device drivers, 8.18. Utilities for user-level device drivers && 2.5.5 Responding to external events (for the IRQ handling)
Cheers,
Alex.
[0] repos/os/src/test/pci/test.cc [1] repos/os/run/pci.run [2] repos/os/src/drivers/platform/spec/x86/README [3] repos/os/include/spec/x86/platform_session/client.h [4] repos/os/include/spec/x86/platform_device/client.h