--- wikisrc/ports.mdwn	2018/10/26 21:07:34	1.17
+++ wikisrc/ports.mdwn	2018/11/11 16:31:56	1.20
@@ -20,7 +20,7 @@ Currently there are 8 ports with Tier I 
 
 [[!table data="""
 Port		|CPU		|Machines						|Latest Release
-aarch64		|aarch64	|64-bit ARM CPUs					|Not yet released
+[[aarch64]]	|aarch64	|64-bit ARM CPUs					|Not yet released
 [[amd64]]	|x86_64		|64-bit x86-family machines with AMD and Intel CPUs	|[8.0](http://www.netbsd.org/releases/formal-8/)
 [[evbarm]]	|arm		|ARM evaluation boards					|[8.0](http://www.netbsd.org/releases/formal-8/)
 [[evbmips]]	|mips		|MIPS-based evaluation boards				|[8.0](http://www.netbsd.org/releases/formal-8/)
@@ -122,7 +122,7 @@ ports are supported.
 
 [[!table data="""
 CPU		|Tier(s)	|Ports(s)
-aarch64		|I		|aarch64
+aarch64		|I		|[[aarch64]]
 alpha		|II		|[[alpha]]
 arm		|I, II		|[[acorn32]] [[cats]] [[epoc32]] [[evbarm]] [[hpcarm]] [[iyonix]] [[netwinder]] [[shark]] [[zaurus]]
 hppa		|II		|[[hppa]]
@@ -139,3 +139,15 @@ sparc64		|I		|[[sparc64]] (Can also run 
 vax		|II		|[[vax]]
 x86_64		|I		|[[amd64]] (Can also run i386 binaries), xen
 """]]
+
+## Various ways of denoting ports and CPUs
+
+When discussing ports and CPUs, there are two concepts, each of which have three ways of being named.  Strictly, the word port refers to the value shown by "uname -m", and typically corresponds to a directory under src/sys.  build.sh supports aliases, which are passed as if they were a port, but expand to a port and a cpu (MACHINE and MACHINE_ARCH); an example is evbearmv7hf-el which expands to the evbarm port and earmv7hf cpu.
+
+[[!table data="""
+concept | /usr/share/mk variable | uname | build.sh
+port | MACHINE      | uname -m | build.sh -m
+cpu  | MACHINE_ARCH | uname -p | build.sh -a
+"""]]
+
+Additonally, there are things referred to as ports which are not actually "uname -m" values, but are notably different than what would be expected from that port name.  One is xen, which is a system architecture variant of i386/amd64, and aarch64, which is CPU type variant of evbarm.