[Buildroot] [RFC, PATCH 6/8] package/petitboot: Add petitboot, the userspace bootloader

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Jeremy Kerr,

On Thu, 16 Jan 2014 16:52:18 +0800, Jeremy Kerr wrote:

> diff --git a/package/petitboot/Config.in b/package/petitboot/Config.in
> new file mode 100644
> index 00000000..2f587c06
> --- /dev/null
> +++ b/package/petitboot/Config.in
> @@ -0,0 +1,10 @@
> +config BR2_PACKAGE_PETITBOOT
> +	bool "petitboot"
> +	depends on BR2_PACKAGE_KEXEC || BR2_PACKAGE_KEXEC_LITE

I don't think we want a dependency here, as it's not necessarily
obvious that this needs a kexec implementation. Therefore, I think we
should have something like:

	select BR2_PACKAGE_KEXEC_LITE if !BR2_PACKAGE_KEXEC

So that at least one implementation is guaranteed to be selected.

> +	select BR2_PACKAGE_NCURSES
> +	select BR2_PACKAGE_UDEV

This has to be a "depends on", and actually should depend on
BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_UDEV. See
http://git.buildroot.net/buildroot/tree/package/modem-manager/Config.in
for an example of a package that requires udev support to be available.

> +	select BR2_PACKAGE_POWERPC_UTILS if BR2_powerpc
> +	help
> +	  Petitboot is a small kexec-based bootloader
> +
> +	  http://www.kernel.org/pub/linux/kernel/people/geoff/petitboot/petitboot.html
> diff --git a/package/petitboot/S14silence-console b/package/petitboot/S14silence-console
> new file mode 100755
> index 00000000..65702005
> --- /dev/null
> +++ b/package/petitboot/S14silence-console
> @@ -0,0 +1,9 @@
> +#!/bin/sh
> +
> +case "$1" in
> +    start)
> +        echo 0 0 7 0 > /proc/sys/kernel/printk
> +        ;;
> +esac
> +
> +exit 0
> diff --git a/package/petitboot/S15pb-discover b/package/petitboot/S15pb-discover
> new file mode 100755
> index 00000000..ebdf9449
> --- /dev/null
> +++ b/package/petitboot/S15pb-discover
> @@ -0,0 +1,23 @@
> +#!/bin/sh
> +
> +LOGFILE=/var/log/petitboot/pb-discover.log
> +PIDFILE=/var/run/petitboot.pid
> +
> +case "$1" in
> +    start)
> +        ulimit -c unlimited
> +        mkdir -p $(dirname $LOGFILE)
> +        PATH=/usr/bin:/usr/sbin:/bin:/sbin pb-discover -l $LOGFILE &
> +        echo $! > $PIDFILE
> +        ;;
> +    stop)
> +        pid=$(cat $PIDFILE)
> +        [ -n "$pid" ] && kill -TERM $pid
> +        ;;
> +    *)
> +        echo "Usage: $0 {start|stop}"
> +        exit 1
> +        ;;
> +esac
> +
> +exit 0
> diff --git a/package/petitboot/kexec-restart b/package/petitboot/kexec-restart
> new file mode 100755
> index 00000000..0175e76d
> --- /dev/null
> +++ b/package/petitboot/kexec-restart
> @@ -0,0 +1,8 @@
> +#!/bin/sh
> +
> +/usr/sbin/kexec -f -e
> +
> +while :
> +do
> +    sleep 1
> +done
> diff --git a/package/petitboot/petitboot-console-ui.rules b/package/petitboot/petitboot-console-ui.rules
> new file mode 100644
> index 00000000..74648562
> --- /dev/null
> +++ b/package/petitboot/petitboot-console-ui.rules
> @@ -0,0 +1,5 @@
> +
> +# spawn a petitboot UI on common user-visible interface devices
> +SUBSYSTEM=="tty", KERNEL=="hvc*", RUN+="/usr/libexec/petitboot/pb-console --getty --detach -- -n -i 0 $name vt100"
> +SUBSYSTEM=="tty", KERNEL=="tty0", RUN+="/usr/libexec/petitboot/pb-console --getty --detach -- -n -i 0 $name vt100"
> +SUBSYSTEM=="tty", KERNEL=="ttyS*", RUN+="/usr/libexec/petitboot/pb-console --getty --detach -- -n -i 0 $name vt100"
> diff --git a/package/petitboot/petitboot.mk b/package/petitboot/petitboot.mk
> new file mode 100644
> index 00000000..b8a2179d
> --- /dev/null
> +++ b/package/petitboot/petitboot.mk
> @@ -0,0 +1,57 @@
> +#############################################################
> +#
> +# petitboot
> +#
> +#############################################################

80 # signs.

Empty new line needed after comment header.

> +PETITBOOT_VERSION = af805399

We want full git hashes.

> +PETITBOOT_SITE = git://git.ozlabs.org/home/jk/git/petitboot
> +PETITBOOT_DEPENDENCIES = ncurses udev

If kexec is only a runtime dependency (and not a build dependency),
then there should be a comment above the "select" of kexec in the
Config.in that says it's only a runtime dependency.

Same thing for powerpc-utils.

> +PETITBOOT_LICENSE = GPLv2
> +PETITBOOT_LICENSE_FILES = COPYING
> +
> +PETITBOOT_CONF_OPT += --with-ncurses --without-twin-x11 --without-twin-fbdev \
> +		      --localstatedir=/var --with-tftp=busybox \

The --with-tftp=busybox seems to implies that Busybox is used.
Technically speaking, Buildroot allows to build a root filesystem
without Busybox. So either you should support both Busybox-based and
non-Busybox based filesystems, or depend/select Busybox.

> +		      HOST_PROG_KEXEC=/usr/sbin/kexec \
> +		      HOST_PROG_SHUTDOWN=/usr/libexec/petitboot/bb-kexec-reboot
> +
> +ifdef PETITBOOT_DEBUG

Where is PETITBOOT_DEBUG defined?

> +PETITBOOT_CONF_OPT += --enable-debug
> +endif
> +
> +ifeq ($(BR2_PACKAGE_NCURSES_WIDEC),y)
> +PETITBOOT_CONF_OPT += --with-ncursesw MENU_LIB=-lmenuw FORM_LIB=-lformw
> +endif
> +
> +define PETITBOOT_PRE_CONFIGURE_BOOTSTRAP
> +	(cd $(@D) && ./bootstrap $(PETITBOOT_VERSION))
> +endef
> +
> +PETITBOOT_PRE_CONFIGURE_HOOKS += PETITBOOT_PRE_CONFIGURE_BOOTSTRAP

It's unfortunate that we can't use the normal <pkg>_AUTORECONF = YES
logic, due to how configure.ac is generated from configure.ac.in.
Anyway, if you do want to call the bootstrap script, you need to make
this package depend on host-autoconf, host-automake and maybe
host-libtool if you're using libtool.

Also, I see in your configure.ac.in that you use Lex and Yacc.
Therefore, your package should depend on host-bison and host-flex.
These are not mandatory dependencies of Buildroot.

> +
> +define PETITBOOT_POST_INSTALL
> +	$(INSTALL) -D -m 0755 $(@D)/utils/bb-kexec-reboot \
> +		$(TARGET_DIR)/usr/libexec/petitboot
> +	$(INSTALL) -d -m 0755 $(TARGET_DIR)/etc/petitboot/boot.d
> +	$(INSTALL) -D -m 0755 $(@D)/utils/hooks/01-create-default-dtb \
> +		$(TARGET_DIR)/etc/petitboot/boot.d/
> +	$(INSTALL) -D -m 0755 $(@D)/utils/hooks/20-set-stdout \
> +		$(TARGET_DIR)/etc/petitboot/boot.d/
> +
> +	$(INSTALL) -D -m 0755 package/petitboot/S14silence-console \
> +		$(TARGET_DIR)/etc/init.d/
> +	$(INSTALL) -D -m 0755 package/petitboot/S15pb-discover \
> +		$(TARGET_DIR)/etc/init.d/
> +	$(INSTALL) -D -m 0755 package/petitboot/kexec-restart \
> +		$(TARGET_DIR)/usr/sbin/
> +	$(INSTALL) -D -m 0755 package/petitboot/petitboot-console-ui.rules \
> +		$(TARGET_DIR)/etc/udev/rules.d/
> +	$(INSTALL) -D -m 0755 package/petitboot/removable-event-poll.rules \
> +		$(TARGET_DIR)/etc/udev/rules.d/
> +
> +	ln -sf /usr/sbin/pb-udhcpc \
> +		$(TARGET_DIR)/usr/share/udhcpc/default.script.d/
> +endef
> +
> +PETITBOOT_POST_INSTALL_TARGET_HOOKS += PETITBOOT_POST_INSTALL
> +
> +$(eval $(autotools-package))
> diff --git a/package/petitboot/removable-event-poll.rules b/package/petitboot/removable-event-poll.rules
> new file mode 100644
> index 00000000..b736aef6
> --- /dev/null
> +++ b/package/petitboot/removable-event-poll.rules
> @@ -0,0 +1,4 @@
> +
> +# petitboot needs notification for media change events on removable devices,
> +# which we only get if we've set the poll_msecs sysfs attribute.
> +ACTION!="remove", ATTR{removable}=="1", ATTR{events_poll_msecs}="2000"

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com