From bcc04b2880b44140176e1d2dcc955a3d3942c392 Mon Sep 17 00:00:00 2001 From: Darren Hart Date: Wed, 13 Jun 2012 21:05:17 -0700 Subject: tiny-init: Basic init mechanism for poky-tiny Currently poky-tiny images will boot and run /bin/sh, which results in error messages to the console about being unable to open the tty and job control being disabled. The shell must be session leader to open the tty, and the tty must not be /dev/console (it should be a vt or a physical tty like ttyS0), the tty is required for job control (handling signals, etc.). The goals of poky-tiny are to be an initial starting point from which to build a distribution that does what you want, and NOTHING more. This patch results in a system that boots with the virtual filesystems mounted, the local network interface up, and a shell with job control running, and a hook (/etc/rc.local) for easy customization. Nothing else. Enabling the basic busybox init, including the ability to give the controlling console to commands starting with a dash in inittab results in a 5664 byte delta (compared with 2560 bytes for enabling setsid and cttyhack). Note that the help in busybox suggests the cttyhack may be more reliable than the init support for handing over the controlling terminal. So the difference between using a standard init and just enabling the two options is about 3k, but enabling setsid and cttyhack may enable others to things besides what I am looking to do. Enabling init in both DISTRO_FEATURES and busybox is fairly trivial to do, so I think it's better to leave that as something to add if needed, rather than something to remove, as that is more consistent with the goals of poky-tiny. Thanks to Tim Bird for his suggestion to include support for rc.local by default. (From meta-yocto rev: 5ae60ed46b34cbf4ab17fe7eab3d46e2f78ee7b8) Signed-off-by: Darren Hart CC: Tim Bird CC: Thomas Frydrych CC: Thomas Petazzoni CC: Paul Eggleton CC: Phil Blundell CC: Khem Raj CC: Koen Kooi Signed-off-by: Richard Purdie --- meta-yocto/conf/distro/poky-tiny.conf | 2 +- meta-yocto/recipes-core/tiny-init/files/init | 21 ++++++++++++++++ .../recipes-core/tiny-init/files/rc.local.sample | 23 ++++++++++++++++++ meta-yocto/recipes-core/tiny-init/tiny-init.bb | 28 ++++++++++++++++++++++ 4 files changed, 73 insertions(+), 1 deletion(-) create mode 100644 meta-yocto/recipes-core/tiny-init/files/init create mode 100644 meta-yocto/recipes-core/tiny-init/files/rc.local.sample create mode 100644 meta-yocto/recipes-core/tiny-init/tiny-init.bb (limited to 'meta-yocto') diff --git a/meta-yocto/conf/distro/poky-tiny.conf b/meta-yocto/conf/distro/poky-tiny.conf index a34c7dc6ca..8ae1d85e8a 100644 --- a/meta-yocto/conf/distro/poky-tiny.conf +++ b/meta-yocto/conf/distro/poky-tiny.conf @@ -95,7 +95,7 @@ DISTRO_FEATURES = "${DISTRO_FEATURES_TINY} \ # Use tmpdevfs and the busybox runtime services VIRTUAL-RUNTIME_dev_manager = "" VIRTUAL-RUNTIME_login_manager = "" -VIRTUAL-RUNTIME_init_manager = "" +VIRTUAL-RUNTIME_init_manager = "tiny-init" VIRTUAL-RUNTIME_keymaps = "" # FIXME: Consider adding "modules" to MACHINE_FEATURES and using that in diff --git a/meta-yocto/recipes-core/tiny-init/files/init b/meta-yocto/recipes-core/tiny-init/files/init new file mode 100644 index 0000000000..bf2817d099 --- /dev/null +++ b/meta-yocto/recipes-core/tiny-init/files/init @@ -0,0 +1,21 @@ +#!/bin/sh + +# Mount the Linux kernel virtual filesystems +mount none -t proc /proc +mount none -t sysfs /sys +mkdir /dev/pts +mount none -t devpts /dev/pts + +ifup lo + +# Allow for distro or local customizations +if [ -f /etc/rc.local ] ; then + source /etc/rc.local +fi + +# Become session leader and try to find a real tty (e.g. ttyS0) +while true; do + setsid cttyhack sh + echo "Console sh exited with $?, respawning..." + sleep 1 +done diff --git a/meta-yocto/recipes-core/tiny-init/files/rc.local.sample b/meta-yocto/recipes-core/tiny-init/files/rc.local.sample new file mode 100644 index 0000000000..d9e198a200 --- /dev/null +++ b/meta-yocto/recipes-core/tiny-init/files/rc.local.sample @@ -0,0 +1,23 @@ +#!/bin/sh + +# Start services and customize the boot process here. +echo "Running /etc/rc.local..." + +# Use init scripts included with packages such as dropbear +#/etc/init.d/dropbear start + +# Spawn a getty manually +#setsid /sbin/getty 115200 ttyS2 + +# Print a banner +#echo "You are running a poky-tiny image brought to you by the Yocto Project." + +# Setup a debugging environment +#mkdir /debugfs +#mount none -t debugfs /debugfs + +# Load modules (note: linux-yocto-tiny does not have module support by default) +#modprobe yourdriver + +# DO NOT run any long running tasks or loops as these will delay +# the /init script and the console shell. diff --git a/meta-yocto/recipes-core/tiny-init/tiny-init.bb b/meta-yocto/recipes-core/tiny-init/tiny-init.bb new file mode 100644 index 0000000000..f5892ed472 --- /dev/null +++ b/meta-yocto/recipes-core/tiny-init/tiny-init.bb @@ -0,0 +1,28 @@ +SUMMARY = "Poky-tiny init" +DESCRIPTION = "Basic init system for poky-tiny" +LICENSE = "MIT" +LIC_FILES_CHKSUM = "file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420" + +PR = "r0" + +RDEPENDS_${PN} = "busybox" + +SRC_URI = "file://init \ + file://rc.local.sample \ + " + +do_configure() { + : +} + +do_compile() { + : +} + +do_install() { + install -d ${D}${sysconfdir} + install -m 0755 ${WORKDIR}/init ${D} + install -m 0755 ${WORKDIR}/rc.local.sample ${D}${sysconfdir} +} + +FILES_${PN} = "/init ${sysconfdir}/rc.local.sample" -- cgit v1.2.3-54-g00ecf