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    SubjectRe: [PATCH] x86: set Pentium M as PAE capable
    On 02/25/2014 05:45 AM, H. Peter Anvin wrote:
    > On 02/24/2014 10:01 PM, Chris Bainbridge wrote:
    >> Pentium M is PAE capable but does not indicate so in the CPUID response.
    >> This is an issue now that some distributions are no longer shipping
    >> non-PAE kernels (those distributions no longer boot on Pentium M). This
    >> small patch fixes the issue by forcing the PAE capability on Pentium M.
    >>
    >> For more discussion see https://bugs.launchpad.net/baltix/+bug/930447
    >>
    >
    > 1. This patch doesn't match the discussion in the link.
    > 2. You would have to also enable this in the cpu testing code in
    > arch/x86/boot.
    > 3. At the very least we need to print a serious warning that the CPU
    > is being run outside its specifications. I have no personal
    > information about why this CPUID bit was disabled, but it could be
    > that it was discovered in testing that it didn't work correctly in
    > all circumstances (e.g. high temperature.) This is very much "use
    > at your own risk..."; you could get data corruption or even
    > hardware damage.
    >
    > We should probably also taint the kernel.

    Perhaps obviously, this should require either command line or build opt-in.

    Regards,
    Peter Hurley



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