loader: always install help files

Address two issues with current help file logic:

The existing condition prevents the common help file from being
installed when there are no additional help files defined. This results
in no loader.help on EFI platforms, for example.

Second, due to the fact that we build and install multiple loader types,
each successive install will clobber the previous loader.help. The
result is that we could lose type-specific commands, or possibly list
them in loaders that do not have such commands.

Instead, give each loader type a uniquely named help file. The EFI
loader will look for /boot/loader.help.efi, userboot will look for
/boot/loader.help.userboot, etc. The interpreter variant has no effect
on which help file is loaded.

This leaves the old /boot/loader.help unused.

Some credit for the final approach goes to Mathieu <sigsys@gmail.com>
for their version of the fix in https://reviews.freebsd.org/D22951.

PR:		267134
Reported by:	Daniel O'Connor <darius@dons.net.au>
Reviewed by:	imp
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D28591

9 files changed, 24 insertions, 8 deletions

diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
index ed6d929dd79b..b1b896a77925 100644
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -52,6 +52,9 @@
 #   xargs -n1 | sort | uniq -d;
 # done
 
+# 20230203: loader help files renamed
+OLD_FILES+=boot/loader.help
+
 # 20230201: timeout moved from /usr/bin to /bin
 OLD_FILES+=usr/tests/usr.bin/timeout/Kyuafile
 OLD_FILES+=usr/tests/usr.bin/timeout/timeout_test
diff --git a/stand/common/commands.c b/stand/common/commands.c
index d86c1a4a6f96..6643a3ca360e 100644
--- a/stand/common/commands.c
+++ b/stand/common/commands.c
@@ -123,7 +123,6 @@ help_emitsummary(char *topic, char *subtopic, char *desc)
 	return (pager_output("\n"));
 }
 
-
 static int
 command_help(int argc, char *argv[])
 {
@@ -132,7 +131,8 @@ command_help(int argc, char *argv[])
 	char	*topic, *subtopic, *t, *s, *d;
 
 	/* page the help text from our load path */
-	snprintf(buf, sizeof(buf), "%s/boot/loader.help", getenv("loaddev"));
+	snprintf(buf, sizeof(buf), "%s/boot/%s", getenv("loaddev"),
+	    HELP_FILENAME);
 	if ((hfd = open(buf, O_RDONLY)) < 0) {
 		printf("Verbose help not available, "
 		    "use '?' to list commands\n");
diff --git a/stand/efi/loader/Makefile b/stand/efi/loader/Makefile
index 2aaba4fbb377..4c94f67cf4e0 100644
--- a/stand/efi/loader/Makefile
+++ b/stand/efi/loader/Makefile
@@ -83,6 +83,7 @@ CFLAGS+= -DEFI_SECUREBOOT
 
 NEWVERSWHAT=	"EFI loader" ${MACHINE}
 VERSION_FILE=	${.CURDIR}/../loader/version
+HELP_FILENAME=	loader.help.efi
 
 # Always add MI sources
 .include	"${BOOTSRC}/loader.mk"
diff --git a/stand/i386/loader/Makefile b/stand/i386/loader/Makefile
index 99a814497802..088629a70b7f 100644
--- a/stand/i386/loader/Makefile
+++ b/stand/i386/loader/Makefile
@@ -62,6 +62,7 @@ CFLAGS.main.c+=	-I${SYSDIR}/contrib/openzfs/include/os/freebsd/zfs
 .if exists(${.CURDIR}/help.i386)
 HELP_FILES=	${.CURDIR}/help.i386
 .endif
+HELP_FILENAME=	loader.help.bios
 
 # Always add MI sources
 .include	"${BOOTSRC}/loader.mk"
diff --git a/stand/kboot/Makefile b/stand/kboot/Makefile
index 745dcd30a938..922944707340 100644
--- a/stand/kboot/Makefile
+++ b/stand/kboot/Makefile
@@ -44,6 +44,8 @@ CFLAGS+=        -I${SYSDIR}/contrib/openzfs/include/os/freebsd/zfs
 HAVE_ZFS=yes
 .endif
 
+HELP_FILENAME=	loader.help.kboot
+
 .include	"${BOOTSRC}/fdt.mk"
 
 # We share bootinfo.c with efi
diff --git a/stand/loader.mk b/stand/loader.mk
index 9fa4c74e2501..b30e9f4e66b7 100644
--- a/stand/loader.mk
+++ b/stand/loader.mk
@@ -162,12 +162,17 @@ vers.c: ${LDRSRC}/newvers.sh ${VERSION_FILE}
 CFLAGS+=	-DELF_VERBOSE
 .endif
 
-.if !empty(HELP_FILES)
+# Each loader variant defines their own help filename. Optional or
+# build-specific commands are included by augmenting HELP_FILES.
+.if !defined(HELP_FILENAME)
+.error Define HELP_FILENAME before including loader.mk
+.endif
+
 HELP_FILES+=	${LDRSRC}/help.common
 
-CLEANFILES+=	loader.help
-FILES+=		loader.help
+CFLAGS+=	-DHELP_FILENAME=\"${HELP_FILENAME}\"
+CLEANFILES+=	${HELP_FILENAME}
+FILES+=		${HELP_FILENAME}
 
-loader.help: ${HELP_FILES}
+${HELP_FILENAME}: ${HELP_FILES}
 	cat ${HELP_FILES} | awk -f ${LDRSRC}/merge_help.awk > ${.TARGET}
-.endif
diff --git a/stand/powerpc/ofw/Makefile b/stand/powerpc/ofw/Makefile
index 28eb8ee91fad..5912ceae93d5 100644
--- a/stand/powerpc/ofw/Makefile
+++ b/stand/powerpc/ofw/Makefile
@@ -37,6 +37,7 @@ SRCS+=		trampolineLE.S
 .endif
 
 HELP_FILES=	${FDTSRC}/help.fdt
+HELP_FILENAME=	loader.help.ofw
 
 # Always add MI sources
 .include	"${BOOTSRC}/loader.mk"
diff --git a/stand/uboot/Makefile b/stand/uboot/Makefile
index ed2253cdae6f..5b8275a0131b 100644
--- a/stand/uboot/Makefile
+++ b/stand/uboot/Makefile
@@ -35,7 +35,8 @@ WARNS?=		1
 CWARNFLAGS.self_reloc.c+=	-Wno-error=maybe-uninitialized
 .endif
 
-HELP_FILES=	 ${.CURDIR}/help.uboot ${BOOTSRC}/fdt/help.fdt
+HELP_FILES=	${.CURDIR}/help.uboot ${BOOTSRC}/fdt/help.fdt
+HELP_FILENAME=	loader.help.uboot
 
 # Always add MI sources
 .include	"${BOOTSRC}/loader.mk"
diff --git a/stand/userboot/userboot/Makefile b/stand/userboot/userboot/Makefile
index c5e2e6fe7c7c..43011b9577c9 100644
--- a/stand/userboot/userboot/Makefile
+++ b/stand/userboot/userboot/Makefile
@@ -54,6 +54,8 @@ CFLAGS+=	-DUSERBOOT_ZFS_SUPPORT
 HAVE_ZFS=yes
 .endif
 
+HELP_FILENAME=	loader.help.userboot
+
 # Always add MI sources
 .include	"${BOOTSRC}/loader.mk"
 CFLAGS+=	-I.