mem=4096M gives error 28: cannot fit into memory

[DiBosco]

I have successfully installed Mageia 1 on a new laptop. It has 4G RAM some of which is shared by the graphics controller (this may or may not be important).

I am needing to get a National Instruments driver/library working which which can take a maximum of 4G memory and it's a well known work around to put mem=4096M into grub. I have done this on three other machines running Mandriva and this has done the trick nicely. One difference might be that the other machines have nvidia cards and so don't have shared memory.

Anyway, at boot I get:

error 28: Selected item cannot fit into memory with a load of other information that, if it is likely to help I can give you by typing it in on another machine.

Anyone know why this might be? I have tried using the desktop kernel as I wondered whether it might be some weird thing with the server kernel saying it's for i686 with 64G RAM. This didn't help at all.

Thanks!

[Ken-Bergen]

I think you answered your own question, by the time grub gets to look at the memory there isn't 4096M left as the video card has already taken some.
If the video card has memory of it's own it should be possible to turn off the sharing in the bios as a test.

[DiBosco]

I don't think I have answered the question as even mem=2048M doesn't work. mem=512M does, but I've got way more than that, even allowing for the card, surely?!

[Ken-Bergen]

I don't think I have answered the question as even mem=2048M doesn't work. mem=512M does, but I've got way more than that, even allowing for the card, surely?!

Strange.
Just a thought but the mem= switch maybe looking for contiguous memory and if you have two SIMM modules and the video card draws some from each there wouldn't be enough in either.
Again, can you turn off sharing in the bios at least for a test?

[DiBosco]

The BIOS is very basic indeed. It's a laptop, there's next to nothing the user can alter. Certainly nothing about shared RAM.

[doktor5000]

Could you please post a link to the driver/library which you originally wanted to install?

[DiBosco]

This is it:

http://joule.ni.com/nidu/cds/view/p/id/2044/lang/en

I would stress this is running on 2010.0, 2010.2 (x2). There's a funky grub thing going on. I have seen a Fedora 13/14 thing with Grub 0.97. I am beginning to suspect this is nothing to do with Mageia, but all to do with the BIOS and Grub.

[DiBosco]

OK, for anyone else who might come across this, here is the solution:

Go to the console and type dmesg > filenameofyourchoice.txt

Examine filenameofyourchoice.txt

Find this section (was at the top for me):

Code: Select all

    /bin/dmesg:

    ...

    BIOS-provided physical RAM map:
    BIOS-e820: 0000000000000000 - 000000000009ec00 (usable)
    BIOS-e820: 000000000009ec00 - 00000000000a0000 (reserved)

<snip>

    BIOS-e820: [B]0000000100000000[/B] - 0000000100600000 (usable)

Note the number in bold.

Then as a grub parameter instead of mem=4096M use:

memmap=4096M$0x100000000

Obviously, replace 4096M with whatever you actually want and 0x100000000 with whatever your last line is that says useable.

[doktor5000]

Code: Select all

<snip>

    BIOS-e820: [B]0000000100000000[/B] - 0000000100600000 (usable)

Note the number in bold.

FWIW, code-tags don't allow for BBCodes, you have to use a quote-tag if you want to apply formatting to it.

[DiBosco]

Ah,yes, hadn't noticed that. You can do it on Linuxquestions!