Reinstate mention of chroot(2) and user quoting

That should clarify the implications of, e.g. symlink behaviour inside
the directory being served.

Input OK schwarze jmc

usr.sbin/tftpd/tftpd.8

@@ -1,4 +1,4 @@
-.\"   $OpenBSD: tftpd.8,v 1.12 2025/05/18 07:01:41 kn Exp $
+.\"   $OpenBSD: tftpd.8,v 1.13 2025/05/22 05:58:36 kn Exp $
 .\"
 .\" Copyright (c) 1983, 1991 The Regents of the University of California.
 .\" All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"	from: @(#)tftpd.8	6.7 (Berkeley) 5/13/91
 .\"
-.Dd $Mdocdate: May 18 2025 $
+.Dd $Mdocdate: May 22 2025 $
 .Dt TFTPD 8
 .Os
 .Sh NAME
@@ -77,7 +77,13 @@ network bootloaders access this path to harvest entropy during
 kernel load.
 .Pp
 .Nm
-needs to start as root and drops privileges to the _tftpd user.
+needs to start as root, then calls
+.Xr chroot 2
+into
+.Ar directory ,
+and drops privileges to the
+.Dq _tftpd
+user.
 .Pp
 The options are as follows:
 .Bl -tag -width Ds
@@ -149,6 +155,7 @@ Allow files to be written to.
 .El
 .Sh SEE ALSO
 .Xr tftp 1 ,
+.Xr chroot 2 ,
 .Xr pxeboot 8 ,
 .Xr syslogd 8 ,
 .Xr tftp-proxy 8