FreeBSD on GA-E7AUM-DS2H with Over 2GB of RAM

Written by Tatyana Hiko < tatyana at miko dot org >

=ChangeLog=
Initial Release (Dec 1, 2009)

Abstract

Gigabyte technology's MPC7A Motherboard GA-E7AUM-DS2H has a bug in its BIOS. (This bug still remains in the latest BIOS, version F4)

Due to this problem this motherboard won't work with FreeBSD stably if

you are using the onboard VGA, and if
you are using over 2GB of memory.

You can avoid this problem by

using PCIe VGA card instead of the onboard VGA, or by
decreasing the amount of memory to 2GB

though, here I want to try to find a software solution.

What is wrong?

Basically this BIOS returns an incorrect SMAP information which has an overlap area during a free area (100000:bfdf0000) and the frame buffer (70000000:10000000).

BASE	LENGTH	TYPE
0	9e800	1
9e800	800	2
f0000	10000	2
100000	bfdf0000	1
70000000	10000000	2
80000000	3fef0000	1
bfef0000	3000	4
bfef3000	d000	3
ea000000	2000000	2
fec00000	1400000	2
100000000	40000000	1

* bfdf0000 should be 6ff00000

So, we can avoid this problem by patching the FreeBSD boot loader to convert this incorrect SMAP information into a correct one which hasn't any overlapping area.

How to patch and rebuild the boot loader

To patch and rebuild the FreeBSD boot loader, first of all, you have to decrease the RAM to 2GB and install the FreeBSD properly. After that you can patch the source tree like the following.

$ mkdir ~/Sources
$ cd ~/Sources
$ wget http://miko.org/~tatyana/tech/FreeBSD/FreeBSD_8.2_GA-E7AUM-DS2H_Over2GB.diff
$ openssl rmd160 FreeBSD_8.2_GA-E7AUM-DS2H_Over2GB.diff
RIPEMD160(FreeBSD_8.2_GA-E7AUM-DS2H_Over2GB.diff)= 522615669719b4cac3a0f6a838fefdc00a93bcdb
$ cd /usr/src
$ sudo patch -p0 < ~/Sources/FreeBSD_8.2_GA-E7AUM-DS2H_Over2GB.diff

After the patching, try to build and install the boot loader.

$ cd /usr/src/sys/boot
$ sudo make clean
$ sudo make obj
$ sudo make depend
$ sudo make
$ cd i386/loader
$ sudo make install
$ cd ../..
$ sudo make clean

Thanks

Thanks to adidasprince's Chameleon patch.

return