This HOWTO explains how to use coreboot on the ASUS M4A78-EM board.

Status

Device/functionality	Status	Comments
CPU
CPU works	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	Tested: AMD Sempron 140.
L1 cache enabled	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	-
L2 cache enabled	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	-
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 }}" | Untested
Hardware virtualization	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested	-
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	N/A
DDR2	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	1G tested
DDR3	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Dual channel support	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
ECC support	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
On-board Hardware
On-board IDE 3.5"	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	Tested: CD/DVD-RW
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	Tested: SATA port 1.
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	Mouse attached crashes SeaBIOS
On-board VGA	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	Tested: DVI and analog VGA. Untested: HDMI.
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 }}" | Untested	-
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 }}" | Unknown	Recognized, but operation unstable
Mini-PCI add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
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 }}" | N/A
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 }}" | Untested
PCI Express x2 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
PCI Express x4 add-on cards	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
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 }}" | Untested
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	There is no floppy connector at all.
Serial port 1 (COM1)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | OK	COM1 is only pin header on board. DB-9 serial connector is available, but not included with board.
Serial port 2 (COM2)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | N/A
Parallel port	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested	No connector, pin header on board only.
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 }}" | N/A
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 }}" | Untested
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 }}" | OK	Single temperature reported.
Hardware watchdog	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
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 }}" | OK	Powernow-K8 works.
Other powersaving features	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
ACPI	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested	-
Reboot	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | No
Poweroff	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | No
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 }}" | N/A
High precision event timers (HPET)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | No	Linux detects, but disables HPET.
Random number generator (RNG)	OK=lime | TODO=red | No=red | WIP=orange | Untested=yellow | N/A=lightgray | yellow }}" | Untested
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 }}" |
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 }}" | OK

Building coreboot

See the Build HOWTO for general information on how to build coreboot.

This board is very similar to ASUS M4A785-M. The major differences are

• Chipset is AMD 780G and SB700 (instead of 785G and SB710).
• On-board VGA is ATI Radeon HD3200 (instead of HD4200), PCI id 1002:9610 (instead of 1002:9710), and
• One of the six SATA ports is eSATA.

There is now (tested on revision 6151) support for M4A78-EM in Coreboot.

Get the Coreboot sources and build tools. Download or build a SeaBIOS binary.

VGA BIOS for the onboard ATI Radeon can be extracted from the original BIOS with the bios_extract utility.

Invoke menuconfig.

• Select Mainboard to be Asus M4A78-EM, ROM chip size 1 MB.
• From "Console options" select "Use onboard VGA as primary video device" if you use the onboard ATI Radeon.
• Add the extracted VGA BIOS, set PCI ids to 1002,9610.
• Add SeaBIOS payload.

Compile with make and flash.

ROM Chip

Up-to-date Flashrom should be able to detect, read, and write the BIOS ROM. The chip is 8 Mbit cFeon EN25F80. It is in DIP-8 package and installed in a socket, so it can be changed without soldering. The ROM is accessed via the SPI protocol. I also tested a Macronix MX25L8005 chip as a substitute, and it worked fine.

Known issues

• Disable configuration option "Chipset" -> "Run non-VGA option ROMs" if there are PCI cards with BIOS. PCI card BIOS may need (Sea)BIOS services to run, and crash if invoked from Coreboot directly.
• Boot succeeds with Intel e100 network card or Tekram TR-822 SATA card, and Linux loads card drivers, but operation was not confirmed. Network card did not manage to transfer data, although link was established. SATA card was tested only for booting. SeaBIOS recognized the controller and drive, but GRUB failed to load completely.

RAM

• 1 GB RAM (1 x Kingston KVR800D2N5/1G) - Boots

Payloads

• SeaBIOS version 0.6.1 works
  • Can boot Debian Linux from SATA drive via Grub2.
• Coreinfo works.
  • Both as standalone payload or loaded from SeaBIOS
  • Both serial port and VGA+PS2 keyboard work.
• FILO works ok.