USB Boot

Peter Stuge stuge-linuxbios at
Wed Jun 2 06:41:01 CEST 2004

On Tue, Jun 01, 2004 at 09:42:20PM -0700, YhLu wrote:
> OHCI usb boot ok now.

Agree with Eric, congratulations! :)

> But it is some slow, only 173KB/S, 
> Full speed should be 12Mbps/8 = 1500KB/s

Actually not. 12Mbps is the speed on the USB wire and each of the
protocols in the stack and in the application causes some overhead,
as you know.

I don't know much specifically about USB storage but I'd guesstimate
the maximum possible throughput somewhere between 1000kb/s and
1400kb/s. The simplest optimization is to increase the block
transfer size to always try to transfer full 64kb, if that hasn't
been done already.

Great to have a complete USB boot solution anyway!


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