> >    - All of the Linux ports provide the same API.
> 
> Does the same numbered syscall do the same thing on different ports or
> doesn't it?  

I said API.  

It does not matter what system call it is mapped to.  It may be a libc
implementation detail for what it is worth. 

> Is the same errno the same error on different ports or
> isn't it?  

Errno values are the same from the point of view of the source code.
I have yet to see a Linux/Intel binary running on Linux/SPARC. 

> Do the different ports use the same data structures or subtly
> different ones?  

Reordered ones.  But then again, there is *ABSOLUTELY* nothing wrong
from changing the layout of the data structures from one port to the
next one.  

Of course, if you like to code stuff with hard coded constants, your
code will not compile.  Probably we are looking at the real problem
here?

> But after the amount of adaptation Linux has done for each port, I think
> it is reasonable to ask if it is the same OS on each platform.

You did not read my pervious post.  Did you?  

It is the same OS on each platform.  It provides the same services.

> If this technique makes porting Linux to new platforms so much easier,
> why does NetBSD (which has been around for less time) support so many
> more platforms?

Besides trying to elude the discussing point with a completely
orthogonal argument, your statement is incorrect.

BSD and BSD ports have existed for a longer time than Linux has.
Linux appeared in 1991.  By then, BSD was already ported to several
architectures.

> Several people have pointed out how this is less flexible than NetBSD's
> emulation layer...

Less flexible?  I do not see where did we loose flexibility at all.
It has yet to be proven.  

> You yourself said, in your last post, that your method was ugly and
> confusing to newcomers, but was chosen to complete the port more
> quickly.  

I did not say ugly.  Nor confusing to newcomers.  

It may be confusing for people trying to get a Linux-compat package
ported from Intel to SPARC, but I do not see many people running into
this problem, besides this effort.  Do you?

Please, go reread my previous post and make sure you assimilate the
ideas before replying.

best wishes,
Miguel.
-- 
miguel@kernel.org