Re: 4GB of memory and NForce4SLI

Thomas Backlund wrote:

> Giuseppe Ghib=F2 wrote:
>=20
>> I tried currently 2006.0 with kernel 2.6.12.18mdksmp-x86_64 into
>> a MSI K8N Diamond Plus motherboard with Athlon64-X2 4800. The
>> motherboard has chipset Nforce4-sli and 4 modules of 1GB each.
>>
>> Currently the BIOS sees 3328MB of memory and in such way
>> it correctly boots with 2.6.12.18mdksmp and free shows
>> 3350260 kB free mem with the 'free' command.
>> How to obtain the rest of 700MB of memory? OK, there is the addressing
>> space for PCI, etc., but for instance other mobos shows more than 3.3G=
B.
>> E.g. on Tyan 2885 I see 4096MB in BIOS and 3559132 with 'free'.
>>
>=20
> Atleast MSI nforce4 boards does only support ~3.5GB memory without the=20
> "memory hole" enabled...
>=20
>> The K8N Diamond has an option in BIOS to "Enable Hardware Memory Hole"=
,
>> which enable memory remapping around the memory hole. The CPU needed
>> for this option is at least stepping E0. A64-4800X2 is stepping E6
>> so should be supported. Once the "Hardware Memory Hole" has been
>> enabled the BIOS sees 4096MB of memory. But the kernel is no
>> longer able to boot. Latest logs were:
>>
>> ...
>> Freeing unused kernel memory: 196k freed
>> Kernel panic - not syncing: No init found. Try passing init=3D option =
to=20
>> kernel
>>
>=20
> you need to tell it how much memory you have using the "mem=3D" boot=20
> option...

I tried with mem=3D... too but up to 4096m you always get only 3.25GB.
With mem=3D4099m xfs is not starting anymore, and with bigger values such
as mem=3D4103m, or even mem=3D5120m, mem=3D5G it
goes in kernel panic.

>=20
> check this:
> http://hardware.mcse.ms/archive20-2005-8-216970.html
>=20
> at the end one user states:
>=20
> <quote>
>=20
>> Found the solution. Set the BIOS to Fill Memory Hole and then told Lin=
ux
>> it had 5G, i.e. mem=3D5G on the boot line.
>>
>> BTW a mem=3D line is required if when you set the BIOS to Fill Memory =
Hole,
>> without it you'll get a kernel panic when you boot. The FC3 installer=20
>> just
>> does a straight boot so it will panic on a machine with the Fill Memor=
y
>> Hole option set in the BIOS.
>=20
> </quote>
>=20
>=20
>> I tried also with kernel-2.6.14.2mdksmp-x86_64 but same results. Even
>> with kernel-linus-2.6.16.15mdksmp-x86_64 gives the same (plus error
>> during 3ware modules scsi probing:
>>
>> scsi: host 0 channel 0 id 0 lun 0x5a5a5a5a5a5a5a5ahas LUN larger than
>> currently supported.
>>
>> Bugs in kernel IOMMU?
>>
>=20
> you can also try booting with iommu=3Dforce

didn't help.

>=20
>=20
>> Bye
>> Giuseppe.
>>
>=20