Placeholder for EPIA-M850 board. Content coming soon. Please yell at mrnuke on #coreboot if nothing changes soon. He's from Texas, he won't mind.

The EPIA-M850 is a mini-ITX board from VIA. It comes with either a 1.3GHz or 1.6GHz via Nano CPU, and a VX900 chipset.

This board is not fully supported. It has a number of issues one should be prepared to deal with.

1. On DIMMs with two memory ranks, odd ranks are disabled by default. The memory initialization does not deal with odd ranks very well, and leaves them disabled.
2. Even with a VGA BIOS, you will get a garbled display. GRUB2 and linux are able to get a working text console though, but only if a VGA BIOS has been run.
3. IRQs only work in PIC mode (no APIC and no ACPI). Do not expect to boot anything other than linux, and be prepared to boot with "noapic acpi=off 3": that is disable APICs _and_ do not use ACPI _and_ start in runlevel 3.
4. Cards plugged in PCI-Express slots may not work.
5. Linux sometimes likes to just hang. It stops responding: no serial output, no panic message, no response to keyboard presses.

If you still want to try coreboot on this board, have a way to recover by flashing externally in case things go south. There is an SPI header that can be used to reprogram the ROM if the board is powered off. flashrom does NOT work when running coreboot; this is NOT a good recovery plan.

Status

Device/functionality	Status	Comments
CPU
CPU works	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
L1 cache enabled	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	Always on
L2 cache enabled	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	Always on
L3 cache enabled	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Multiple CPU support	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Multi-core support	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Hardware virtualization	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | ?
RAM
EDO	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
SDRAM	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
SO-DIMM	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
DDR	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
DDR2	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
DDR3	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Even ranks only
Dual channel support	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
ECC support	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board Hardware
On-board IDE 3.5"	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A	N/A
On-board IDE 2.5"	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board SATA	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
On-board SCSI	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
On-board USB	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
On-board VGA	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not OK
On-board Ethernet	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
On-board Audio	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | ?
On-board Modem	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board FireWire	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board Smartcard reader	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board CompactFlash	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board PCMCIA	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board Wifi	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board Bluetooth	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
On-board SD card reader	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Add-on slots/cards
ISA add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Audio/Modem-Riser (AMR/CNR) cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PCI add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Mini-PCI add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
Mini-PCI-Express add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
PCI-X add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
AGP graphics cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PCI Express x1 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | ?
PCI Express x2 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | ?
PCI Express x4 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | ?
PCI Express x8 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PCI Express x16 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PCI Express x32 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
HTX add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Legacy / Super I/O
Floppy	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Serial port 1 (COM1)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
Serial port 2 (COM2)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Parallel port	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PS/2 keyboard	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
PS/2 mouse	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Game port	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Infrared	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PC speaker	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
DiskOnChip	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Input
Trackpoint	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Touchpad	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Fn Hotkeys	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Fingerprint Reader	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Laptop
Docking VGA	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Docking LAN	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Docking USB	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Docking Audio	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Docking Displayport	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Thinklight	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Webcam	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Miscellaneous
Sensors / fan control	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Hardware watchdog	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
SMBus	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
CAN bus	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
CPU frequency scaling	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Other powersaving features	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
ACPI	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Zero
Reboot	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Poweroff	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Suspend	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
Nonstandard LEDs	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK
High precision event timers (HPET)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Not tested
Random number generator (RNG)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Wake on modem ring	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
Wake on LAN	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
Wake on keyboard	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
Wake on mouse	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
TPM	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Unknown
Flashrom	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | No	Only works with vendor BIOS

Getting ready for coreboot

Do not expect a graphics console to work

Prepare an external programmer

The EPIA-M850 has an SPI ROM. The ROM can be programmed externally via the SPI header. (TODO: Add picture and pinout of header). While the board is powered off, a programmer is generally capable of supplying enough power. An FT4232H module has been tested to work.

Make sure the programmer can read the chip. If it can't read it, it won't be able to write it in case recovery is needed.

Extract the VGA BIOS

Use bios_extract to to get the VGA BIOS from the vendor's BIOS. Put it in an easy-to-find place. Let's call it path/to/vgabios.bin.

Configure coreboot

Run either

$ make menuconfig

or

$ make xconfig

• Mainboard -> Select VIA->EPIA-M850
• VGA BIOS -> Select "Add a VGA BIOS image" + "VGA BIOS path and filename:" path/to/vgabios.bin
• Console -> Make sure serial console is on and turned all the way up to SPEW (in case things go south)
• System tables -> Make sure at least a PIRQ table is generated. Generating other tables does not hurt us, so they can remain enabled.
• Debugging -> Output verbose RAM init debug messages.
• For the first try, it is higly recommended to use SeaBIOS as a payload.
• Save and exit

Configure linux

For the time being, append the following options to the boot parameters: "acpi=off noapic 3" to the linux that will be booting this board after coreboot finishes. If you forget to do this, you will also be able to change them at the GRUB2 prompt, assuming you are using GRUB2.

Prepare a serial console

The board has a serial port in the back. How convenient! Use it.

Build and flash coreboot

Start monitoring the serial console and power on the board

If you encounter any errors, or even if you succeed and are happy, let us know.

Hacking

SPI header

The board features a conveniently located SPI header that can be used to program the ROM when the board is powered off. The pinout is incorrectly documented in the user manual.

2:	GND	#CS	MOSI	? PCIRST ?
1:	VCC	CLK	MISO	NC

Photos

• 

  Board, top

• 

  Board, bottom

• 

  SPI header

• 

  Headers for three additional serial ports