Re: 4GB of memory and NForce4SLI

Giuseppe Ghib=F2 wrote:
> 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 3.3GB=
.
> E.g. on Tyan 2885 I see 4096MB in BIOS and 3559132 with 'free'.
>

Atleast MSI nforce4 boards does only support ~3.5GB memory without the=20
"memory hole" enabled...

> 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 t=
o=20
> kernel
>

you need to tell it how much memory you have using the "mem=3D" boot=20
option...

check this:
http://hardware.mcse.ms/archive20-2005-8-216970.html

at the end one user states:

<quote>
> Found the solution. Set the BIOS to Fill Memory Hole and then told Linu=
x
> 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 H=
ole,
> 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 Memory
> Hole option set in the BIOS.
</quote>


> 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?
>

you can also try booting with iommu=3Dforce


> Bye
> Giuseppe.
>

--=20
Regards

Thomas