In OpenPOWER land we have a project called op-test-framework which (for all its strengths and weaknesses) allows us to test firmware on a variety of different hardware platforms and even emulators like Qemu.| sthbrx.github.io
Just recently Petitboot added a method to ask the user for a password before allowing certain actions to proceed. Underneath the covers this is checking against the root password, but the UI "pop-up" asking for the password is relatively generic. Something else which has been on the to-do list for a while is support for mounting encrpyted partitions, but there wasn't a good way to retrieve the password for them - until now!| sthbrx.github.io
Quite often when building small Linux images having separate user accounts isn't always at the top of the list of things to include. Petitboot is no different; the most common operations like mounting disks, configuring interfaces, and calling kexec all require root and Petitboot generally only exists long enough to boot into the next thing, so why not run it all as root?| sthbrx.github.io
On platforms that support it Petitboot can interact with the inband IPMI interface to pull information from the BMC. One particularly useful example of this is the "Get System Boot Options" command which we use to implement boot "overrides". By setting parameter 5 of the command a user can remotely force Petitboot to boot from only one class of device or disable autoboot completely. This is great for automation or debug purposes, but since it can only specify device types like "disk" or "netw...| sthbrx.github.io
A neat piece of kernel code dropped into my lap recently, and as a way of| sthbrx.github.io
Since at least v1.0.0 Petitboot has used device-mapper snapshots to avoid| sthbrx.github.io
Generally when someone wants to install a Linux distro they start with an ISO| sthbrx.github.io
A Google search for 'Petitboot' brings up results from a number of places, some describing its use on POWER servers, others talking about how to use it on the PS3, in varying levels of detail. I tend to get a lot of general questions about Petitboot and its behaviour, and have had a few requests for a broad "Welcome to Petitboot" blog, suggesting that existing docs deal with more specific topics.. or that people just aren't reading them :)| sthbrx.github.io
In POWER land IPMI is mostly known as the method to access the machine's console and start interacting with Petitboot. However it also has a plethora of other features, handily described in the 600ish page IPMI specification (which you can go read yourself).| sthbrx.github.io
One of the cool features of POWER8 processors is the ability to run in either big- or little-endian mode. Several distros are already available in little-endian, but up until recently Petitboot has remained big-endian. While it has no effect on the OS, building Petitboot little-endian has its advantages, such as making support for vendor tools easier.| sthbrx.github.io
The way autoboot behaves in Petitboot has undergone some significant changes recently, so in order to ward off any angry emails lets take a quick tour of how the new system works.| sthbrx.github.io