OpenBMC cheatsheet

This document is intended to provide a set of recipes for common OpenBMC customisation tasks, without having to know the full yocto build process.

Using a local kernel build

The kernel recipe is in:

 meta-phosphor/common/recipes-kernel/linux/linux-obmc_4.2.bb

To use a local git tree, change the SRC_URI to a git:// URL without a hostname. For example:

SRC_URI = "git:///home/jk/devel/linux;protocol=git;branch=${KBRANCH}"

The SRCREV variable can be used to set an explicit git commit. The default (${AUTOREV}) will use the latest commit in KBRANCH.

Building for Palmetto

The Palmetto target is palmetto.

If you are starting from scratch without a build/conf directory you can just:

$ cd openbmc
$ TEMPLATECONF=meta-openbmc-machines/meta-openpower/meta-ibm/meta-palmetto/conf . oe-init-build-env
$ bitbake obmc-phosphor-image

Building for Barreleye

The Barreleye target is barreleye.

If you are starting from scratch without a build/conf directory you can just:

$ cd openbmc
$ TEMPLATECONF=meta-openbmc-machines/meta-openpower/meta-rackspace/meta-barreleye/conf . oe-init-build-env
$ bitbake obmc-phosphor-image

Building the OpenBMC SDK

Looking for a way to compile your programs for 'ARM' but you happen to be running on a 'PPC' or 'x86' system? You can build the sdk receive a fakeroot environment.

$ bitbake -c populate_sdk obmc-phosphor-image
$ ./tmp/deploy/sdk/openbmc-phosphor-glibc-x86_64-obmc-phosphor-image-armv5e-toolchain-1.8+snapshot.sh

Follow the prompts. After it has been installed the default to setup your env will be similar to this command

. /opt/openbmc-phosphor/1.8+snapshot/environment-setup-armv5e-openbmc-linux-gnueabi

Rebuilds & Reconfiguration

You can reconfigure your build by removing the build/conf dir:

rm -rf build/conf

and running oe-init-build-env again (possibly with TEMPLATECONF set).

Useful dbus CLI tools

busctl

http://www.freedesktop.org/software/systemd/man/busctl.html

Great tool to issue dbus commands via cli. That way you don't have to wait for the code to hit the path on the system. Great for running commands with QEMU too!

Run as:

busctl call <path> <interface> <object> <method> <parameters>

• <parameters> example : sssay "t1" "t2" "t3" 2 2 3

Using QEMU

QEMU has a palmetto-bmc machine (as of v2.6.0) which implements the core devices to boot a Linux kernel. OpenBMC also maintains a tree with patches on their way upstream or temporary work-arounds that add to QEMU's capabilities where appropriate.

QEMU's wiki has instructions for building from source.

Assuming the CWD is the root of the openbmc tree, a palmetto-bmc machine can be invoked with:

qemu-system-arm \
    -M palmetto-bmc \
    -m 256 \
    -append "console=ttyS4" \
    -nographic \
    -kernel build/tmp/deploy/images/palmetto/cuImage-palmetto.bin \
    -dtb build/tmp/deploy/images/palmetto/cuImage-aspeed-bmc-opp-palmetto.dtb \
    -initrd build/tmp/deploy/images/palmetto/obmc-phosphor-image-palmetto.cpio.gz

To quit, type Ctrl-a c to switch to the QEMU monitor, and then quit to exit.