Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

A number of places in the source tree still reference cuad.* after
sio(4) was deprecated by uart(4).

s/cuad/cuau/g/

PR: docs/171533
Reviewed by: imp
Approved by: cperciva (implicit)
MFC after: 3 weeks

o Correct comments: remove a reference to non-existent gdbinit.9 man page;
correct a path to the kernel build directory; gdb lost -k key.

Reviewed by: grog
MFC after: 1 week

Catch up with PHK's sio(4) cuaa->cuad rework [sys/dev/sio/sio.c rev. 1.456].

Remove vinum bits.

Add comments to deter people from using this file directly. That's
not the intention.

Rearrange "you may want to change these values" values to the top, and
reduce their number as much as possible.

tr macro: Require a parameter (because gdb is too stupid to understand
optional parameters), and create macros tr0, tr1 and trf which call it
to connect to /dev/cuaa0, /dev/cuaa1 and firewire connections
respectively.

Split kld symbol load into two separate macros: revision 1.5
simplified things for the /dev/mem case, but broke it for anything
else. Now the simple /dev/mem version is called kldsyms, and the
version for serial debugging and processor dumps is called getsyms,
and still requires this irritating cut and paste.

Change comments on startup to make life easier for the poor
(de)bugger.

Add a "-f" flag for asf(8) which performs a search to find the each module
no matter where in the directory structure it may be. Use this and the "-k"
flag in the generated gdbinit files so that the "getsyms" function in gdb
requires no user intervention to run and will find every module if they're
in the kernel build's module directory. This is still quite useful for
cases where gdb knows that the path for some modules is /boot/kernel and
others are in the object directory for /usr/src/sys/$ARCH/compile/kernel.

Approved by: grog

Replace hard-coded module path with a keyword which gets changed when
the kernel is built.

Terminate echoed lines. Unlike echo(1), gdb echo doesen't
automatically terminate them.

Modify startup mode: don't specify the file name for the debug kernel,
so it needs to be (and can be) specified on the command line. Don't
try to automatically connect to a remote machine, so that the same
.gdbinit file can be used for analysing processor dumps.

Add macros for kernel debugging. These have been around for a
while, and they will need some more tuning before they're really
useful, but at the moment they're better than nothing.

Indirectly reminded by: dwhite