Comment 13 for bug 316079
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| Hugo Grostabussiat (bonstra) wrote Re: Asus M51SE's video card won't work with 4GB RAM (BIOS bug ?) | #13 |
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0f7b58d
(Get the code!)
Hello b4b1z,
What you describe here is a common problem with 32 bit systems equipped with 4 GB of RAM (or more).
When running in 32 bit mode, the processor only have access to 4 GB of physical memory. The reason why you can only use 3 GB of them is that the last GB of memory is used by PCI devices to provide access to their internal memory (e.g. the video memory of your graphics card).
If you have a look at your /proc/iomem, you can see that there is no System RAM beyond 0xbffa0000 because all the space is used by PCI devices or reserved by the BIOS.
A feature present on most recent processors allow to extend the processor's physical address space up to 64 GB so you can have access to your whole physical memory. It is called Physical Address Extension (PAE) and is supported by Linux.
To enable it, you will need to reconfigure your kernel. Search for "High Memory Support" in "Processor type and features" and select "64 GB" (HIGHMEM64G) some additional configuration options should appear, the interesting one is labeled "PAE (Physical Address Extension) Support", enable it and start the compilation process.
I hope that will help.
Regards.