Allwinner A20 (dual core Cortex A7)

[Warner Losh]

On Jul 31, 2013, at 8:05 PM, Ganbold Tsagaankhuu wrote:

> Hi Hans and all,
> 
> Just tried to run freebsd on Cubieboard2 with some minor modification to
> timer code for A10.
> However after detecting usb it just stops near "Root mount waiting for:
> usbus1". I see light on usb stick. System supposed to mount rootfs from usb
> stick and usb stick was prepared by using Tim's crochet script.
> 
> Dmesg: http://pastebin.com/7WkkExN2
> 
> What problem it could be? Any suggestions?

Clocks. I'd make sure that all the clocks are spun up correctly. On other ARM cores if you do this wrong (and it tends to be different for different SoCs), then you get weird usb behavior.

Interrupts. When interrupts aren't routed correctly, usb misbehaves (although not that badly).

Cache. Maybe the cache lines are bigger (though doubtful, since the A10 has an A7 inside, iirc). If so, then USB_DMA_ALIGNMENT may need to be bumped.

Warner