From coreboot
Revision as of 22:07, 14 May 2017 by Taiidan (talk | contribs) (added back recommended cpus list - do not remove this - people want to know that these are the only ones worth getting)
Jump to navigation Jump to search

The wiki is being retired!

Documentation is now handled by the same processes we use for code: Add something to the Documentation/ directory in the coreboot repo, and it will be rendered to Contributions welcome!

ASUS KGPE-D16 on the development stand at Raptor Engineering.

To boot with a second CPU package installed, the 2nd EPS12V connector MUST be connected to a 8-pin power source that has sufficient amperage (Using a converter is risky).

General Information

The KGPE-D16 is a AMD Family 10h / 15h, dual-CPU server and workstation motherboard released in 2009 (ASUS). It is well supported and stable under Coreboot, with all CPUs, RAM, and peripherals functioning normally. Family 10h (61xx) processors do not currently support the isochronous mode required to enable the IOMMU, but Family 15h (62xx, 63xx) processors work well with the IOMMU enabled.

This board is automatically tested by Raptor Engineering's test stand. For more details please visit AutoTest/RaptorEngineering.

A basic system diagram is available in the official manual, which can be downloaded from ASUS directly or from Puget Systems. The diagram is available in Appendix A.1 and has been confirmed to match the hardware shipping from ASUS. Not indicated are the PCIe lane widths for the gigabit network controller, which are both x1. All legacy PCI devices share the same bus, and partially due to this design the SP5100 has severe issues with bridging high-bandwidth PCI peripherals. As such, an external PCI-PCIe bridge is recommended should you need to interface a high bandwidth legacy PCI device to this system; ASMedia controllers have been verified to function correctly.

Northbridge functions are distributed between the CPU internal northbridge and the SR5690 northbridge, which is effectively a HyperTransport to ALink/PCIe translator and switch. There is a separate SP5100 southbridge device, adjacent to the northbridge and residing under the smaller heatsink of the two. This device provides all traditional southbridge services including the LPC bridge and SATA controllers. All southbridge-destined messages, including CPU-originated power state control messages over HyperTransport, pass through the CPU northbridge and are routed to the southbridge via the SR5690 northbridge device.

Incidentally, this design places the IOMMU, which is part of the SR5690, in the correct location to properly shield the main CPU from all unauthorized traffic. If the southbridge connected directly to a HyperTransport link there would be no way to prevent unauthorized DMA from legacy PCI devices connected to the southbridge, or even from the southbridge's embedded microprocessor.

The flash chip is in a PDIP 8 socket (SPI flash chip) on the motherboard.

Installation Notes

  • coreboot must be flashed externally when migrating from the proprietary BIOS. After coreboot has been flashed and booted at least once, flashrom can safely reprogram the ROM under Linux.
  • When migrating from the proprietary BIOS, after flashing coreboot the CMOS memory *must* be cleared. Failing to clear the CMOS will typically result in odd hangs during the boot process.
  • Enabling the serial console or EHCI debug console will drastically increase the time needed to boot.
  • The proprietary BMC module must be removed for coreboot to function.
  • The 63xx "Piledriver" series processors require microcode updates to enable IOMMU (Errata) and may require microcode updates for safe operation due to the 2016 gain-root-via-NMI exploit.
  • Fan control is via software with coreboot, you can use fancontrol/pwmconfig to control your 4pin PWM fans - coreboot sets them = 100% at boot-time.
  • 12 and 16 core CPU's are split in to two NUMA nodes, memory is divided based on NUMA nodes (1 6282SE 16 core CPU, 2 Nodes, 32GB RAM, 16GB per node)
  • Turbo 2 and power saving seems to require a tickless system to function (nohz=on in the kernel cmdline), otherwise the extra cores are always woken up and will never enter CC6.


Hardware Features - at a glance
Format SSI-EEB
Socket G34
Max Processors 2
Max RAM 128 GB
PCI-e slots 4 5 physical, 4 concurrent
PCI slots 1 Via PCI Bridge that also connects onboard AST graphics chip
Other Expansion Slots 1 PIKE ASUS Proprietary I/O Expansion Slot, Insert PIKE RAID card for second half of the motherboard SATA/SAS ports
EEPROM Type DIP 8 SPI Socket
Factory EEPROM Size 2MB
Max EEPROM Size ???
TPM YES With Owner Controlled CRTM - TPM is an option addon module
Crossfire XDMA ??? Has ACS and dual PCI-e 2.0 x16 slots, so it should work (reported working on vendor bios, need tester for coreboot)

Binary Situation
Blob Free Operations YES
Native GFX Init Partial Text Mode Only Now features proper EDID parsing.
OpenBMC Network KVM Firmware Soon See Below

IOMMU YES v1.26 with Interrupt Remapping
IOMMU for Graphics YES Near-Native 3D gaming performance with proper software configuration
SR-IOV ???
PCI-e ARI ??? Required for more than 8 SR-IOV VF per device

OpenBMC - Network KVM

Raptor Engineering is working on porting OpenBMC to the KGPE-D16 and KCMA-D8 under a crowdfunded contract, it should be done in a few months.

Note: You will probably require the ASUS ASMB4-iKVM module to use it.


The following RAM models and configurations have been tested by either Raptor Engineering or a third party and are know to work as of the stated GIT revision. The bolded configuration is automatically tested by Raptor Engineering on every coreboot GIT commit and for most relevant Gerrit changesets; please see the board-status repository for the latest tested GIT hash.

Manufacturer Model Size Speed Type ECC Populated Slots CPU Mainboard Firmware
Micron 36KSF2G72PZ-1G4E1 (N/A) 16GB DDR3-1333 Registered Yes A2 / C2 Opteron 6378 ASUS KGPE-D16 Coreboot 2268e0d or later
Hynix/Hyundai HMT151R7BFR4C-H9 4GB DDR3-1333 Registered Yes A2 / C2 Opteron 6276 ASUS KGPE-D16 Libreboot 437619c
Kingston 9965525-055.A00LF 8GB DDR3-1600 Unbuffered Yes A2 / C2 / E2 / F2 Opteron 6328 ASUS KGPE-D16 Coreboot 9fba481
Kingston KVR16R11D4/16 (9965516-483.A00LF) 16GB DDR3-1600 Registered Yes All orange slots (128GB) Opteron 6278/6262HE ASUS KGPE-D16 Libreboot 20160907
Kingston KVR16R11D4K4/64I (9965516-477.A00LF) 16GB DDR3-1600 Registered Yes All orange slots (128GB) Opteron 6278/6262HE/6284SE ASUS KGPE-D16 Libreboot 20160907
crucial ("crucial by Micron") CT16G3ERSLD4160B (MT36KSF2G72PZ-1G6P1NE) 16GB DDR3-1600 Registered Yes All orange slots (128GB) Opteron 6278/6262HE ASUS KGPE-D16 Libreboot 20160907

Processor Summary

In addition to the 1 or 2 main CPUs, there are no less than three known secondary processors present on the mainboard. All are disabled when running under coreboot.

  • There is a very poorly documented microprocessor inside the SR5690; purpose and type unknown. It is believed this processor requires a firmware upload from the main platform firmware or via JTAG in order to start execution.
  • A single 8051 processor core is present inside the SB700 southbridge. It normally handles errata related to power states and may also be responsible for the blinking power LED in S3 suspend under the proprietary BIOS. It is believed accesses made by this processor are responsible for the flashrom write failure when the board is booted from the proprietary BIOS. This processor also requires a firmware upload from the main platform firmware or via JTAG in order to start execution.
  • The BMC has an integrated ARM core. This is disabled by pin strap when the BMC firmware module is not installed.

Some processors may be present on or activated by add-on modules:

  • The optional PIKE add-on cards use ARM cores to handle the SAS protocol, though this firmware is directly loaded from a Flash chip on the module and does not involve any non-local components (e.g. the main CPU never touches the firmware on these modules outside of a manual reflash operation). Raptor Engineering is currently unaware of any SAS controllers that operate without a secondary processor or use libre firmware; the protocol is simply too complex to handle via a mask ROM, and as there are only one or two suppliers of SAS controllers there is very little incentive to release the source code to the firmware. Writing a libre firmware to replace the existing firmware may technically be possible, however it is extremely unlikely this will ever happen due to the man-decades required.
  • Installing an ASUS iKVM firmware module will activate the ARM core in the BMC, which has full system access to all peripherals and possibly memory. It is not recommended to use this module as the firmware is both highly privileged and proprietary, and is known to contain at least one critical security bug.

Known Issues

EHCI debug console

The EHCI debug console causes severe USB problems under both Libreboot and coreboot. This typically manifests as very slow boot / slow typing on USB keyboards. This issue appears to extend to the KCMA-D8 and KFSN4-DRE boards as well.


  • Certain hardware revisions of these mainboards appear to contain a bug that leads to a hang in ramstage after cold start, with a varying probability dependent on unknown factors potentially including the debug level, debug output device, and binary Flash layout. Non-affected boards appear to generate an MCE and restart instead of hanging. The hang and/or MCE also appears to be dependent on CPU frequency, with slower CPUs such as the Opteron 6262HE more likely to generate the hang. It is possible, though not confirmed, that the hang is due to generation of an MCE while the SB700 and attached LPC devices are being reconfigured; if this is the case, this would be an unfortunate instance of a hardware bug exposed by coreboot's relatively fast startup.
  • Certain models and populations of DIMMs do not function under either coreboot or the proprietary BIOS. These failures may also be contingent on the exact PCB revision and / or CPU model installed. For a list of known failing combinations please visit KGPE-D16 Known Bad Configurations.

> 128 GB of RAM not working

The KGPE-D16 doesn't work with more than 128 GB RAM (reported by ThomasUmbach) and would need further work by coreboot developers.

Miscellaneous Notes

The 4 total PCI-e slots may be limiting, but as the board has PCI-e ACS you can install an external ACS supporting PCI-e expansion system and still have IOMMU security, ACS support means that the devices beyond the external switch will be placed in separate IOMMU groups and thus you will maintain security and not have to use the unsafe attachment override for attaching devices to virtual machines.

Free Software Foundations "Respects Your Privacy" (RYF) certification

The Asus KGPE-D16 board is being sold with coreboot pre-installed and is the first RYF workstation/server mainboard that was certified by the Free Software Foundation on March 6th, 2017.


Recommended CPU's

Taiidan's list of recommended 16 core g34 CPU's:
Opteron 6386SE (Best) Better than 6287, but "Piledriver" CPU's require microcode updates for secure operation and IOMMU)
Opteron 6287SE (second best)
Opteron 6284SE
Opteron 6282SE The Bargain Bin

Gamer? Taiidan recommends nothing less than a 6386SE (around $200 used) or dual 6328's (one is equivalent to an FX-8370E).

Taiidan's list of recommended 8 core g34 CPU's:
Opteron 6328 (Note: Requires microcode updates for secure operation and IOMMU)

An 8 Core CPU is not really worth it unless you need the better single threaded performance more than the second set of cores, such as if the games you play can't use 16.

External links