bitbake: Use IPK packaging for rootfs assembly

bitbake offers a choice of DEB, RPM or IPK packaging. To a degree the
choice is functionally arbitrary for image generation but control over
the package format becomes important if we want to:

1. Include runtime package management functionality in the firmware image
2. Mess about with the packages on the build system

With respect to 1 the IPK format and opkg (an ipk package manager) are
designed for embedded systems[1] - by contrast to RPMs have heavier
dependencies and a greater impact on the size and complexity of the
firmware image.

Regarding 2, the embedded nature and the need for opkg to work without
much fuss leads to a lower configuration barrier by comparison to RPMs.
With ipk it becomes possible to reuse the packages built during image
preparation for core analysis without needing to generate an SDK:

$ export LD_LIBRARY_PATH=./tmp/work/x86_64-linux/opkg-native/*/recipe-sysroot-native/usr/lib
$ MY_DEBUG_ROOT=tmp/rootfs-debug
$ ./tmp/sysroots-components/x86_64/opkg-native/usr/bin/opkg \
	-f ./tmp/work/p10bmc-openbmc-linux-gnueabi/obmc-phosphor-image/*/opkg.conf \
$ fakeroot ./tmp/sysroots-components/x86_64/opkg-native/usr/bin/opkg \
	-f ./tmp/work/p10bmc-openbmc-linux-gnueabi/obmc-phosphor-image/1.0-r0/opkg.conf \
	install dbus-sensors dbus-sensors-dbg
$ gdb-multiarch
(gdb) set solib-absolute-prefix .../tmp/rootfs-debug
(gdb) add-auto-load-safe-path .../tmp/rootfs-debug
(gdb) file tmp/rootfs-debug/usr/bin/nvmesensor
(gdb) core-file obmcdump_17_9597/core.nvmesensor.0.aae91b519d0e4e0e8bbe746e3f6cd25f.2779.9594000000
Core was generated by `/usr/bin/nvmesensor'.
Program terminated with signal SIGABRT, Aborted.
45      pthread_kill.c: No such file or directory.
(gdb) bt
"xyz.openbmc_project.NVMeSensor", this=0x488f04) at

This approach documented in the Poky Reference Manual:

Switch all machines to IPK to align the debugging experience with
upstream's documentation and to facilitate efficient use of packaged
software at runtime.


Change-Id: I8ef526add2d7a6790de1b3eb3fb85cd39b864f23
Signed-off-by: Andrew Jeffery <>
Signed-off-by: Patrick Williams <>
diff --git a/meta-evb/meta-evb-raspberrypi/conf/local.conf.sample b/meta-evb/meta-evb-raspberrypi/conf/local.conf.sample
index cbfcfe3..88b6391 100644
--- a/meta-evb/meta-evb-raspberrypi/conf/local.conf.sample
+++ b/meta-evb/meta-evb-raspberrypi/conf/local.conf.sample
@@ -1,6 +1,6 @@
 MACHINE ??= "raspberrypi"
 DISTRO ?= "openbmc-phosphor"
-PACKAGE_CLASSES ?= "package_rpm"
+PACKAGE_CLASSES ?= "package_ipk"
 EXTRA_IMAGE_FEATURES ?= "debug-tweaks"
 USER_CLASSES ?= "buildstats"