On Tue, 26 Jul, at 03:55:24PM, Andy Lutomirski wrote: > As currently configured, my laptop cannot boot any existing kernel > because the real mode trampoline can't be reserved. The ranges in > which it could live are rejected by the kernel: one is EFI boot > services data and the other is above the EBDA. > > Allowing use of RAM between the EBDA and 640k is scary: there are > probably many quirky BIOSes out there, and, as currently structured, > it would be awkward to allow it just on EFI boots because we > currently reserve that range before we figure out whether we're > using EFI. > > This series fixes it the other way: it allow the trampoline to live > in boot services memory. It achieves this by deferring the panic > due to failure to reserve a trampoline until early_initcall time > and then adjusting the EFI boot services quirk to reserve space > for the trampoline if we haven't already found it a home. > > I'm hoping this is okay for 4.8 even though it's late: it fixes > a boot failure and it's fairly conservative -- the only significant > changes in behavior should be on systems that currently fail to boot. > > I'm not currently proposing it for stable because AFAIK I'm the > only person to have seen this issue. If it survives in Linus' > tree for a while, though, I might propose it for -stable later > on.
I took a very, very quick look over this series and nothing jumped out as being wrong. I'll take a much closer look this week.
