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    SubjectRe: [PATCH 00/14] RFC: x86: relocatable kernel changes

    Peter do you plan to update pxelinux or other bootloaders to use the
    relocatable kernel feature?

    Can we please kill the gosh awful impact lines? They keep breaking my
    concentration whenever I try and review these patches. They are
    horrible. Something of very minimal significance jumping up and
    screaming at me.

    The impact lines also fail to capture any of the significant ways I
    can easily think of that this patch could cause problems. A little
    screw up could cause the kernel to fail to boot for a random portion
    of our user base, and the patch as constructed will require changes
    to existing bootloaders.

    The direction of this patch seems reasonable. The details are broken.
    The common case for relocatable kernels today is kdump. A situation
    with very minimal memory. In that situation the kernel needs to run
    where we put it, modifying the kernel to not run where it gets put
    is a problem.

    With the code as it is today you can get the exact same behavior
    by simply bumping up the minimum alignment to 16MB, and a lot less code
    and no changes needed to any bootloaders.

    Is your goal to setup a scenario where on small memory systems a bootloader
    like pxelinux can support a relocatable kernel and load it a lower
    address? If so that seems reasonable.

    With that said how about we change the logic to:

    if (load_addr == legacy_load_addr) /* 0x100000 */
    use config_physical_start
    else if aligned
    noop
    else
    /* Crap this is bad align the kernel and hope something works. */

    That gets the desired behavior we override bootloaders that are not
    smart and taking relocation into account. I am really not comfortable
    with having code that will override a bootloader doing something
    reasonable.

    I expect we will still want to update kexec to be able to take
    advantage of loadtime_size (runtime_size seems like the wrong name).

    Eric


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