comparing archs

[M. Warner Losh]

In message: <49EB577A.1070006 at telenix.org>
            Chuck Robey <chuckr at telenix.org> writes:
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: What would be a good arm cpu to use as a comparison, so that I can constrast the
:  Cortex-A8 Armv7A processor in my Pandora against the (whatever) processor which
: would typify the Arm6 architecture that is already implemented in FreeBSD?

That was rather the point of my earlier email: There aren't any armv6
processors implemented today.  Much of the base code is there, but I
don't think we have all the goo in place for an actual SoC.

: Would there be one of those arm11** processors to do it, like maybe the arm1136?
:  Or another one?
: 
: I found that the Arm folks don't release the Armv7 architecture document for the
:  latest version, you need to be a Arm vendor with a "business reason" to get
: that.  I got one for the Arm6 arch, but I'm not sure which particular one
: typifies what FreeBSD's implemented already.

The way to find out what is implemented is to grep the source.  For
example, the atmel AT91RM9200 uses an ARM920T core and implements
armv4.  The Marvel parts implement armv5 (with a few quirks).  You can
tell this by looking at either the cache operations that are defined
for each port, or the bus space operations (they are often optimized
for each rev of ARM spec).

Warner