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

6 files changed, 22 insertions, 4 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index 5051470edc71..9027fe7df841 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -895,9 +895,7 @@ _cgem.4=	cgem.4
 MLINKS+=cgem.4 if_cgem.4
 .endif
 
-.if empty(MAN_ARCH)
-__arches=	${MACHINE} ${MACHINE_ARCH} ${MACHINE_CPUARCH}
-.elif ${MAN_ARCH} == "all"
+.if empty(MAN_ARCH) || ${MAN_ARCH} == "all"
 __arches=	${:!/bin/sh -c "/bin/ls -d ${.CURDIR}/man4.*"!:E}
 .else
 __arches=	${MAN_ARCH}
diff --git a/share/man/man4/man4.aarch64/Makefile b/share/man/man4/man4.aarch64/Makefile
index 6714a47011ef..ef5fcd84ccd4 100644
--- a/share/man/man4/man4.aarch64/Makefile
+++ b/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>
diff --git a/share/man/man4/man4.arm/Makefile b/share/man/man4/man4.arm/Makefile
index 0b3eec427934..2ac8dbb5fd81 100644
--- a/share/man/man4/man4.arm/Makefile
+++ b/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>
diff --git a/share/man/man4/man4.i386/Makefile b/share/man/man4/man4.i386/Makefile
index a21b3cd6302b..e3d2e66ca78d 100644
--- a/share/man/man4/man4.i386/Makefile
+++ b/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>
diff --git a/share/man/man4/man4.powerpc/Makefile b/share/man/man4/man4.powerpc/Makefile
index 05c5d4012fe8..aa0e137fcedd 100644
--- a/share/man/man4/man4.powerpc/Makefile
+++ b/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>
diff --git a/share/man/man5/make.conf.5 b/share/man/man5/make.conf.5
index 5885d9476d71..b3623b29a950 100644
--- a/share/man/man5/make.conf.5
+++ b/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.