Subject: Re: bus.h style question
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Curt Sampson <email@example.com>
Date: 08/18/1997 11:51:32
On Mon, 18 Aug 1997, Jonathan Stone wrote:
> The bus_space interface should provide methods for accessing such
> streams efficiently, without requiring any explicit driver
> byteswapping of `bytestream' data like disk blocks or Ethernet
> packets. I think the reasons for that are obvious.
The reasons for this are not obvious to me. Given the number of
different situations that can occur, the driver is still going to
have to make its own decisions about whether it should swap any
particular set of bytes or not, since only the driver will know a)
whether the data is stream data or not, and b) the endianness and
swapping-capability of the bridges between the device and the CPU,
and the device itself. For bus-related swapping issues, things
would be set up in the bus-specific portion of the driver, rather
than the bus-independent portion of the driver, obviously.
Curt Sampson firstname.lastname@example.org Info at http://www.portal.ca/
Internet Portal Services, Inc. Through infinite myst, software reverberates
Vancouver, BC (604) 257-9400 In code possess'd of invisible folly.