OpenPOWER Foundation Demoes The LibreBMC POWER-Based Open-Source BMC

[phoronix]

Phoronix: OpenPOWER Foundation Demoes The LibreBMC POWER-Based Open-Source BMC

Last year the OpenPOWER Foundation announced LibreBMC as a POWER-based open-source BMC and now they have progressed to the point of actually demoing this BMC backed by a fully open-source software stack...

https://www.phoronix.com/news/LibreBMC-Demo

[linuxgeex]

%$#@! that is a slow boot process. I've heard that Power systems were slow to boot, but I also read numerous articles by IBM research about speeding up the boot process. If this is how fast it is after all those boot acceleration projects, I hate to think how slow it would have been without them!!!

[JEBjames]

Michael

Typo/Grammar

"is using this weeks' Open" should be "is using this week's Open"

"The Microwatt core is running the OpenBMC Linux-based firmware stack." should probably be "The Microwatt core runs the OpenBMC Linux-based firmware stack."

"card with the Microwatt POWER based" should probably be "card with a Microwatt POWER-based" (the = specific vs a/an = non-specific)

[zexelon]

Hmmmm not probably the best news for Raptor computing's uber expensive BMC...

[ryao]

%$#@! that is a slow boot process. I've heard that Power systems were slow to boot, but I also read numerous articles by IBM research about speeding up the boot process. If this is how fast it is after all those boot acceleration projects, I hate to think how slow it would have been without them!!!

That is a 100MHz single core processor. Try running your CPU at 100MHz with SMT+SMP disabled and see how fast it will boot. It will probably not be as slow since it is designed for a much higher power budget.

That said, it is a prototype. I assume that they have not done much performance work yet.

Edit: I just saw the full video. That is an impressively long boot process. I thought you had been complaining about the BMC itself, not the main system boot. That is ridiculously slow. It seems to boot Linux 3 times during the boot process. :/

[linuxgeex]

Edit: I just saw the full video. That is an impressively long boot process. I thought you had been complaining about the BMC itself, not the main system boot. That is ridiculously slow. It seems to boot Linux 3 times during the boot process. :/

Linux is the last stage booted after GRUB menu. Before that you see petitboot running on the BMC console. The BMC console isn't running the code. It's merely echoing what the platform code is dumping to the serial console. The platform in the meanwhile is running in 64k of RAM when it starts up and it does a lot of init to enable all the RAM banks, test them, and then switch to linear addressing. That's why it's so slow - not because it's a microcontroller. And it's AIX, not Linux that you see running in the first couple boot stages.

[onlyLinuxLuvUBack]

That is a 100MHz single core processor. Try running your CPU at 100MHz with SMT+SMP disabled and see how fast it will boot. It will probably not be as slow since it is designed for a much higher power budget.

That said, it is a prototype. I assume that they have not done much performance work yet.

Edit: I just saw the full video. That is an impressively long boot process. I thought you had been complaining about the BMC itself, not the main system boot. That is ridiculously slow. It seems to boot Linux 3 times during the boot process. :/

can't wait for the phoronix boot battle danceoff benchmark : pikvm vs librebmc

[Developer12]

can't wait for the phoronix boot battle danceoff benchmark : pikvm vs librebmc

pikvm can do many things, but it can't boot a POWER cpu

[jeremykerr]

Hi all! Jeremy here, I'm one of the folks behind this demo. A couple of notes from the comments:

Yep, this is pretty slow! As mentioned in the video, we have fast-forwarded through some of the less-interesting boot processes - in this case, the OpenBMC userspace boot, and then parts of the POWER system boot. The former is entirely due to the performance of the FPGA + microwatt "soft-core". Being at 100MHz, it's around one eighth of the clock speed of the original "production" BMC on that machine (an ASPEED AST2500 BMC), However, the FPGA+microwatt core is punching well above its weight for such a low clock speed, and there are a number of potential improvements to be made.

We have a fairly comprehensive write-up of the technical details of the BMC here: https://codeconstruct.com.au/docs/dcscm-openbmc/

The timing of the host system boot (ie, after the BMC is up and running) is partially the boot speed of POWER platform firmware. It's quite involved to begin with, as there's a lot of platform initialisation necessary, as part of the host firmware. There are a few stages involved in getting those CPUs running:

• First, the Self Boot Engine (SBE) starts running, entirely out of the CPU cache
• This loads the main boot-time firmware, called "hostboot". When this starts, it's still running in cache. Amongst other things, it probes the platform DIMMs, initialises them, loads itself to main RAM and runs from there
• Once hostboot is done, it loads the runtime firmware (OPAL). OPAL initialises platform IO to set up the runtime environment for:
• Petitboot, the Linux-based bootloader, which reads the main OS kernel from storage and boots it

Being an OpenPOWER platform, all of these bits of firmware are open source. Being LibreBMC, all of the BMC components are open source too, including the BMC hardware.

The somewhat-slower BMC does increase host-CPU boot time a little too; there are various host-to-BMC interactions during the boot process, like progressive stages of firmware load, and uploading inventory & sensor information to the BMC.

It seems to boot Linux 3 times during the boot process

There are three boots of Linux here:

• you see the BMC boot Linux, in the right-hand terminal. (At this point, the system is still "off"- the main CPUs are not powered)
• the bootloader, petitboot, is Linux-based; there's a fairly quick linux boot when that comes up. you see this in the left-hand host console once firmware is done
• the actual installed OS on the server - an Ubuntu boot at the end, also in the host console

And it's AIX, not Linux that you see running in the first couple boot stages

There's no AIX here - the output on the left is the SBEs, then hostboot, then OPAL, then petitboot, then Ubuntu.