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Blog post by emitrax on Wed, 2007-04-18 17:33

I've been reading some more code and I'm getting more confident with it.

Basically data transfer is done with memcpy.

In the ehci controller, registers are mapped every time a controller is found. This is done in the controller constructor.

As the ehci specs says:
Register Space. Implementation-specific parameters and capabilities, plus operational control and
status registers. This space, normally referred to as I/O space, must be implemented as memory-mapped
I/O space.

So...

EHCI::EHCI(pci_info *info, Stack *stack)
...
 // map the registers
 fRegisterArea = map_physical_memory("EHCI memory mapped registers",
                (void *)physicalAddress, mapSize, B_ANY_KERNEL_BLOCK_ADDRESS,

Browsing the USB Stack code

Blog post by emitrax on Fri, 2007-04-13 21:49

usb, soc, code

I said it already, but I'm going to say it a million of times, I've never EVER would expected to work on such a project for the Google Summer of Code, I actually didn't even think I would get in the soc. But anyway, here I am... so let's begin!

Last night after I got bored reading the Kernel Kit section of the Be Book (it was about threads and related functions), I opened my shell and I dived right into the USB stack code.

I tried to follow some functions with ctags, because I was interested about how the actual data is sent to the device, and here is what I found out.

This is the method used to send data to the device.
GetBusManager()->SubmitTransfer(transfer);

EHCI driver status...

status_t      
EHCI::SubmitTransfer(Transfer *transfer)
{
...