Standalone version

[Hans Petter Selasky]

On Thursday 24 June 2010 14:24:01 Friedrich Schick wrote:
> Hello,
> 
> we have an embedded system running the eCos real-time operating system. Now
> we consider porting the USB stack from FreeBSD to eCos. What needs to be
> done to have a running standalone version of the FreeBSD USB stack? The
>  work may also be interesting to anybody, who runs an embedded system
>  without having a real operting system as FreeBSD or Linux.
> 

Hi,

On the high-level you need to wrap malloc, newbus, thread creation, timers, 
mutexes and condition variables. If you want DMA enabled devices to work like 
the EHCI, you also need a wrapper for busdma. This can be compile-time opted 
out.

I have created a wrapper layer that allows you to compile the core of the 
FreeBSD 8.x USB stack in userspace. I could send you a link off-list if you 
are interested.

Minimum footprint I've seen using the stock USB core is: 64-128Kbytes

It is possible to feature reduce the USB stack and then the executable 
footprint will be reduced aswell.

--HPS