Coreboot-fam15

coreboot-fam15 is a distribution of coreboot for AMD Family 15h hardware, developed by mrothfuss. This version of coreboot utilizes AMD's open source AGESA firmware found in coreboot-4.0. This older version of coreboot can be built by Debian 6. Recent CPU microcode updates and support for the H8DGI motherboard have been added to the codebase (https://github.com/mrothfuss/coreboot-fam15). The AGESA codebase is robust, development primarily involves adding/improving board configurations.

Development Roadmap

Currently the only developer of this project (mrothfuss) is content with the stability, performance, and features of this coreboot release. Information is provided to guide others in developing the missing features they may want. Development by mrothfuss will resume as features are needed or when collaborators join.

Hardware Monitor

There is partial support for the hardware monitor (fan control) in the H8QGI and H8SCM motherboards. The default values need to be improved and the reliability needs to be tested. The H8QGI board is recommended to tune these values as it has a working debugging console. According to documentation, the H8DGI motherboard uses the same hardware monitor; but for unknown reasons coreboot can not find the chip.

1. Improve and validate fan control on the H8QGI motherboard
2. Add support on the H8DGI motherboard

Secondary Northbridge

The H8DGI has 6 PCIe slots, including 3 x16 slots. However, two of these x16 slots are on the secondary northbridge which has not been activated.

1. Test changing the "MAX_NB_COUNT" parameter to 2 (src/mainboard/supermicro/h8dgi/platform_cfg.h)
2. Update the device tree to include the second northbridge (src/mainboard/supermicro/h8dgi/devicetree.cb)

IOMMU

Source code exists to enable the IOMMU (see the IOMMU_SUPPORT_DISABLE parameter). A buffer needs to be allocated and provided to the AGESA/CIMX code before the IOMMU code can be activated/tested.

1. Reserve and allocate memory for the IOMMU buffer
2. Enable and confirm operation of the IOMMU

Debugging Console on H8SCM and H8SGL

The serial console is wired oddly on these two motherboards and does not correctly initialize in coreboot. The best reference to correctly activate serial debugging on these devices is the linux driver for the associated chip.

Additional Motherboards

Initial ports have been made for the ASUS/KGPE-D16, ASUS/KCMA-D8, and Supermicro/H8SGL motherboards. The ASUS motherboards boot, but lack VGA support. The D16 and D8 likely need tuning of the HyperTransport 3 deemphasis settings to be stable. The H8SGL board partially boots, but does not have a debugging console for the same reason as the H8SCM board. The "magic numbers" for RAM SPD parameters likely need to be determined/set for the H8SGL board, but this is impractical to do without a debugging console.

Updating coreboot

The codebase for this port is very old (coreboot 4.0). The fam15h AGESA codebase compiles in coreboot 4.7, but does not actually produce bootable ROMs. It is difficult to setup a verified Debian 6 system to compile the firmware in (the apt repositories for Debian 6 are not online anymore). There are multiple options to improve the buildability of this project.

• Update the build environment to be compatible with more modern versions of GCC (easiest, recommended)
• Fix the AGESA codebase in coreboot 4.7 to be bootable (difficult, but more ideal)
• Incorporate the fam15h AGESA codebase into modern coreboot (monumentous effort, not recommended)

Board Status

Supermicro/H8DGI

Pros

• Stable with as much as 512GB of RAM (atlas)
• Has debugging output on the RS232 port

Cons

• The IOMMU has not been activated
• Secondary northbridge has not been activated, this disables 3 out of the 6 PCIe slots.
• The only active x16 PCIe slot is very close to CPU1; large CPU coolers will obstruct this slot and limit GPU support.
• No fan control or hardware monitor
• No open source BMC (the stock BMC can be disabled by a motherboard jumper)
• Blob required for onboard VGA

Supermicro/H8SCM

Pros

• Stable with as much as 128GB of RAM
• Fan control and hardware monitor are active (limited testing suggests fans only accelerate)

Cons

• No debugging output on the RS232 port
• The IOMMU has not been activated
• No open source BMC (the stock BMC can be disabled by a motherboard jumper)
• Blob required for onboard VGA

Supermicro/H8QGI

Pros

• Has debugging output on the RS232 port
• Fan control and hardware monitor are active (limited testing suggests fans only accelerate)

Cons

• The IOMMU has not been activated
• No open source BMC (the stock BMC can be disabled by a motherboard jumper)
• Blob required for onboard VGA
• Minimally tested

ASUS/KGPE-D16 and ASUS/KCMA-D8

• Initial ports for these boards have been added (develop branch)
• The boards boot and have debugging output on the RS232 port
• The KGPE-D16 passes raminit and executes a coreboot payload
• No video output yet, it is unknown if these ports can actually boot an OS.