The Acer G43T-AM3 is a microATX-sized desktop board. It was used for the Acer models Aspire M3800, Aspire M5800 and possibly more.
+------------------+--------------------------------------------------+ | Northbridge | Intel G43 (called x4x in coreboot code) | +------------------+--------------------------------------------------+ | Southbridge | Intel ICH10R (called i82801jx in coreboot code) | +------------------+--------------------------------------------------+ | CPU socket | LGA 775 | +------------------+--------------------------------------------------+ | RAM | 4 x DDR3-1066 | +------------------+--------------------------------------------------+ | SuperIO | ITE IT8720F | +------------------+--------------------------------------------------+ | Audio | Realtek ALC888S | +------------------+--------------------------------------------------+ | Network | Intel 82567V-2 Gigabit Ethernet | +------------------+--------------------------------------------------+
There is no serial port. Serial console output is possible by soldering to a point at the corresponding Super I/O pin and patching the mainboard-specific code accordingly.
Tests were done with SeaBIOS 1.14.0 and slackware64-live from 2019-07-12 (linux-4.19.50).
+-------------------+---------------------+ | Type | Value | +===================+=====================+ | Socketed flash | No | +-------------------+---------------------+ | Model | Macronix MX25L1605D | +-------------------+---------------------+ | Size | 2 MiB | +-------------------+---------------------+ | Package | 8-Pin SOP | +-------------------+---------------------+ | Write protection | No | +-------------------+---------------------+ | Dual BIOS feature | No | +-------------------+---------------------+ | Internal flashing | Yes | +-------------------+---------------------+
The flash is divided into the following regions, as obtained with ifdtool -f rom.layout backup.rom
:
00000000:00001fff fd 00100000:001fffff bios 00006000:000fffff me 00002000:00005fff gbe
In general, flashing is possible internally and from an external header. It might be necessary to specify the chip type; MX25L1605D/MX25L1608D/MX25L1673E
is the correct one, not MX25L1605
.
Internal access to the flash chip is unrestricted. When installing coreboot, only the BIOS region should be updated by passing the --ifd
and -i bios
parameters to flashrom. A full backup is advisable.
Here is an example:
$ sudo flashrom \ -p internal \ -c "MX25L1605D/MX25L1608D/MX25L1673E" \ -r backup.rom $ sudo flashrom \ -p internal \ -c "MX25L1605D/MX25L1608D/MX25L1673E" \ --ifd -i bios \ -w coreboot.rom
In addition to the information here, please see the :doc:`../../flash_tutorial/index`.
The SPI flash chip on this board can be flashed externally through the SPI_ROM1 header while the board is off and disconnected from power. There seems to be a diode that prevents the external programmer from powering the whole board.
The signal assigment on the header is identical to the pinout of the flash chip. The pinout diagram below is valid when the PCI slots are on the left and the CPU is on the right. Note that HOLD# and WP# must be pulled high (to VCC) to be able to flash the chip.
+---+---+ SPI_CSn <- | x | x | -> VCC +---+---+ SPI_MISO <- | x | x | -> HOLDn +---+---+ WPn <- | x | x | -> SPI_CLK +---+---+ GND <- | x | x | -> SPI_MOSI +---+---+
The Intel Management Engine (ME) can be disabled by setting the ME_DISABLE jumper on the board. It pulls GPIO33 on the ICH10 low, causing the "Flash Descriptor Security Override Strap" to be set. This disables the ME and also disables any read/write restrictions to the flash chip that may be set in the Intel Flash Descriptor (IFD) (none on this board). Note that changing this jumper only comes into effect when starting the board from a shutdown or suspend state, not during normal operation.
To completely remove the ME blob from the flash image and to decrease the size of the ME region, thus increasing the size of the BIOS region, me_cleaner
can be used with the -t
, -r
and -S
options.
There are two fan connectors that can be controlled individually. CPU_FAN can only control a fan by a PWM signal and SYS_FAN only by voltage. See the mainboard's devicetree.cb
file for how coreboot configures the Super I/O to control the fans.
Various similar mainboards exist, like the Acer Q45T-AM. During a discussion in #coreboot on IRC, ECS was suspected to be the original designer of this series of mainboards. They have similar models such as the ECS G43T-WM.