man: Build manpages for all architectures

Building and installing architecture-specific man pages only raises a number of
problems:

 * The https://www.freebsd.org/cgi/man.cgi is incomplete. As an
   example, it does not show results for pae(4). The reason for this is
   that the cgi interface runs on FreeBSD amd64.

 * In FreeBSD amd64 some manual pages have broken X-refs. See hptrr(4)
   for an example.

 * Also, we have broken links in our Release Notes. This is a
   consequence of the first point. See
   https://www.freebsd.org/releases/13.0R/hardware/#proc-i386.

Make MAN_ARCH default to 'all' so we build all the man pages for all the
architectures. The difference in disk space is negligible. Also link
architecture-specific man pages to their own section while keeping their own
namespace.

PR: 212290
Reported by:	mj@bsdops.com
Approved by:	ceri@, wosch@
MFC after:	4 weeks

sbin/Makefile

@@ -90,6 +90,12 @@ SUBDIR.${MK_ZFS}+=	zfsbootcfg
 
 SUBDIR.${MK_TESTS}+=	tests
 
+# Add architecture-specific manpages
+# to be included anyway
+MAN=   sconfig/sconfig.8
+
+.include <bsd.prog.mk>
+
 .include <bsd.arch.inc.mk>
 
 SUBDIR_PARALLEL=

share/man/man4/Makefile

@@ -895,9 +895,7 @@ _cgem.4=	cgem.4
 MLINKS+=cgem.4 if_cgem.4
 .endif
 
-.if empty(MAN_ARCH)
+.if empty(MAN_ARCH) || ${MAN_ARCH} == "all"
-__arches=	${MACHINE} ${MACHINE_ARCH} ${MACHINE_CPUARCH}
-.elif ${MAN_ARCH} == "all"
 __arches=	${:!/bin/sh -c "/bin/ls -d ${.CURDIR}/man4.*"!:E}
 .else
 __arches=	${MAN_ARCH}

share/man/man4/man4.aarch64/Makefile

@@ -17,6 +17,11 @@ MAN=	\
 	rk_i2c.4 \
 	rk_pinctrl.4 \
 
+# Link files to the parent directory
+.for _manpage in ${MAN}
+MLINKS+=${_manpage} ../${_manpage}
+.endfor
+
 MANSUBDIR=/aarch64
 
 .include <bsd.prog.mk>

share/man/man4/man4.arm/Makefile

@@ -18,6 +18,11 @@ MAN=	\
 MLINKS= imx_wdog.4 imxwdt.4
 MLINKS+= mge.4 if_mge.4
 
+# Link files to the parent directory
+.for _manpage in ${MAN}
+MLINKS+=${_manpage} ../${_manpage}
+.endfor
+
 MANSUBDIR=/arm
 
 .include <bsd.prog.mk>

share/man/man4/man4.i386/Makefile

@@ -21,6 +21,11 @@ MLINKS=	CPU_ELAN.4 CPU_SOEKRIS.4
 MLINKS+=pae.4 PAE.4
 MLINKS+=sbni.4 if_sbni.4
 
+# Link files to the parent directory
+.for _manpage in ${MAN}
+MLINKS+=${_manpage} ../${_manpage}
+.endfor
+
 MANSUBDIR=/i386
 
 .include <bsd.prog.mk>

share/man/man4/man4.powerpc/Makefile

@@ -15,6 +15,11 @@ MAN=	adb.4 \
 	snd_davbus.4 \
 	tsec.4
 
+# Link files to the parent directory
+.for _manpage in ${MAN}
+MLINKS+=${_manpage} ../${_manpage}
+.endfor
+
 MANSUBDIR=/powerpc
 
 .include <bsd.prog.mk>

share/man/man5/make.conf.5

@@ -385,7 +385,7 @@ for which section 4 man pages will be installed.
 The special value
 .Sq all
 installs all available architectures.
-The default is the MACHINE and MACHINE_ARCH being built.
+It is also the default value.
 .It Va MODULES_WITH_WORLD
 .Pq Vt bool
 Set to build modules with the system instead of the kernel.

usr.sbin/Makefile

@@ -213,6 +213,13 @@ SUBDIR.${MK_TESTS}+=	tests
 
 .include <bsd.arch.inc.mk>
 
+# Add architecture-specific manpages
+# to be included anyway
+MAN=   apmd/apmd.8 \
+       nvram/nvram.8
+
+.include <bsd.prog.mk>
+
 SUBDIR_PARALLEL=
 
 .include <bsd.subdir.mk>

usr.sbin/apm/Makefile

@@ -5,6 +5,10 @@ MAN=	apm.8
 MLINKS=	apm.8 apmconf.8
 MANSUBDIR= /${MACHINE_CPUARCH}
 
+# Link files to the parent directory
+MLINKS+= apm.8 ../apm.8
+MLINKS+= apmconf.8 ../apmconf.8
+
 PACKAGE=apm
 
 .include <bsd.prog.mk>