> On 9 Mar 2025, at 2:46 PM, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > > On Sun, Mar 09, 2025 at 09:03:29AM +0000, Aditya Garg wrote: >> >> >>>> On 9 Mar 2025, at 2:24 PM, gregkh@xxxxxxxxxxxxxxxxxxx wrote: >>> >>> On Sun, Mar 09, 2025 at 08:40:31AM +0000, Aditya Garg wrote: >>>> From: Paul Pawlowski <paul@xxxxxxxx> >>>> >>>> This patch adds a driver named apple-bce, to add support for the T2 >>>> Security Chip found on certain Macs. >>>> >>>> The driver has 3 main components: >>>> >>>> BCE (Buffer Copy Engine) - this is what the files in the root directory >>>> are for. This estabilishes a basic communication channel with the T2. >>>> VHCI and Audio both require this component. >>> >>> So this is a new "bus" type? Or a platform resource? Or something >>> else? >> >> It's a PCI device > > Great, but then is the resources split up into smaller drivers that then > bind to it? How does the other devices talk to this? We technically can split up these 3 into separate drivers and put then into their own trees. > >>>> VHCI - this is a virtual USB host controller; keyboard, mouse and >>>> other system components are provided by this component (other >>>> drivers use this host controller to provide more functionality). >>> >>> I don't understand, why does a security chip have a USB virtual >>> interface in it? What "devices" hang off of it that are found and >>> enumerated by the host OS? >> >> The t2 chip not only handles security, but also has a usb hub, which connects the internal keyboard, trackpad, touchbar, webcam, and other internal devices. The external usb ports are separate. > > That feels strange, but hey, we've seen worse :) > > thanks, > > greg k-h
