On Thu, Mar 12, 2015 at 04:03:07PM +0300, Stas Sergeev wrote: > Yeah, I realize that, but I was hoping that some work-around > exists. For example, move entire dimm above 4G? Is this really > impossible? Or maybe move overlapping region above 8G...
You /really/ don't want to do that. We have that situation on TI Keystone SoCs and it's really horrible for the kernel to deal with. For early kernel boot, we require RAM below the 4GB boundary, so that we are able to execute code before the MMU is enabled. No RAM below 4GB basically means there is no way to execute any code from RAM. Keystone SoCs work around that by having an alias of RAM below 4GB, and by doing some architecturally dubious, potentially fault-inducing manipulation of the kernel page tables - so dubious that booting Linux on Keystone SoCs with this leads us to print a big warning, and immediately taint the kernel at the moment. That's on my list of things which need to be worked on, subject to commercial issues. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
