Add textdump(4) man page to describe the textdump facility and provide

some stock formulas for use.

Update ddb(4) to reference the textdump(4) page, list the textdump
commands, and suggest using them with scripts and output capture.
Update HISTORY section.

Hook up textdump(4) to build.

MFC after:	3 months

1 files changed, 31 insertions, 0 deletions

diff --git a/share/man/man4/ddb.4 b/share/man/man4/ddb.4
index ea1d907..2caae2d 100644
--- a/share/man/man4/ddb.4
+++ b/share/man/man4/ddb.4
@@ -632,6 +632,14 @@ buffer.
 returns the contents of the buffer as a string to an appropriately privileged
 process.
 .Pp
+This facility is particularly useful in concert with the scripting and
+.Xr textdump 4
+facilities, allowing scripted debugging output to be captured and
+committed to disk as part of a textdump for later analysis.
+The contents of the capture buffer may also be inspected in a kernel core dump
+using
+.Xr kgdb 1 .
+.Pp
 .It Ic run
 .It Ic script
 .It Ic scripts
@@ -640,6 +648,20 @@ Run, define, list, and delete scripts.
 See the
 .Sx SCRIPTING
 section for more information on the scripting facility.
+.Pp
+.It Ic textdump set
+.It Ic textdump status
+.It Ic textdump unset
+The
+.Ic textdump set
+command may be used to force the next kernel core dump to be a textdump
+rather than a traditional memory dump or minidump.
+.Ic textdump status
+reports whether a textdump has been scheduled.
+.Ic textdump unset
+cancels a request to perform a textdump as the next kernel core dump.
+More information may be found in
+.Xr textdump 4 .
 .El
 .Sh VARIABLES
 The debugger accesses registers and variables as
@@ -881,6 +903,7 @@ Other bus' bridge chipsets may be able to generate NMI using bus specific
 methods.
 .Sh SEE ALSO
 .Xr gdb 1 ,
+.Xr kgdb 1 ,
 .Xr acpi 4 ,
 .Xr CAM 4 ,
 .Xr mac_text 4 ,
@@ -900,3 +923,11 @@ This manual page translated from
 .Xr man 7
 macros by
 .An Garrett Wollman .
+.Pp
+.An Robert N. M. Watson
+added support for
+.Nm
+output capture,
+.Xr textdump 4
+and scripting in
+.Fx 8.0 .