https://github.com/torvalds/linux
Revision fedc1ed0f11be666de066b0c78443254736a942e authored by Linus Torvalds on 31 March 2014, 00:26:08 UTC, committed by Linus Torvalds on 31 March 2014, 00:26:08 UTC
Pull vfs fixes from Al Viro: "Switch mnt_hash to hlist, turning the races between __lookup_mnt() and hash modifications into false negatives from __lookup_mnt() (instead of hangs)" On the false negatives from __lookup_mnt(): "The *only* thing we care about is not getting stuck in __lookup_mnt(). If it misses an entry because something in front of it just got moved around, etc, we are fine. We'll notice that mount_lock mismatch and that'll be it" * 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch mnt_hash to hlist don't bother with propagate_mnt() unless the target is shared keep shadowed vfsmounts together resizable namespace.c hashes
Tip revision: fedc1ed0f11be666de066b0c78443254736a942e authored by Linus Torvalds on 31 March 2014, 00:26:08 UTC
Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Tip revision: fedc1ed
efi-stub.txt
The EFI Boot Stub
---------------------------
On the x86 platform, a bzImage can masquerade as a PE/COFF image,
thereby convincing EFI firmware loaders to load it as an EFI
executable. The code that modifies the bzImage header, along with the
EFI-specific entry point that the firmware loader jumps to are
collectively known as the "EFI boot stub", and live in
arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c,
respectively.
By using the EFI boot stub it's possible to boot a Linux kernel
without the use of a conventional EFI boot loader, such as grub or
elilo. Since the EFI boot stub performs the jobs of a boot loader, in
a certain sense it *IS* the boot loader.
The EFI boot stub is enabled with the CONFIG_EFI_STUB kernel option.
**** How to install bzImage.efi
The bzImage located in arch/x86/boot/bzImage must be copied to the EFI
System Partition (ESP) and renamed with the extension ".efi". Without
the extension the EFI firmware loader will refuse to execute it. It's
not possible to execute bzImage.efi from the usual Linux file systems
because EFI firmware doesn't have support for them.
**** Passing kernel parameters from the EFI shell
Arguments to the kernel can be passed after bzImage.efi, e.g.
fs0:> bzImage.efi console=ttyS0 root=/dev/sda4
**** The "initrd=" option
Like most boot loaders, the EFI stub allows the user to specify
multiple initrd files using the "initrd=" option. This is the only EFI
stub-specific command line parameter, everything else is passed to the
kernel when it boots.
The path to the initrd file must be an absolute path from the
beginning of the ESP, relative path names do not work. Also, the path
is an EFI-style path and directory elements must be separated with
backslashes (\). For example, given the following directory layout,
fs0:>
Kernels\
bzImage.efi
initrd-large.img
Ramdisks\
initrd-small.img
initrd-medium.img
to boot with the initrd-large.img file if the current working
directory is fs0:\Kernels, the following command must be used,
fs0:\Kernels> bzImage.efi initrd=\Kernels\initrd-large.img
Notice how bzImage.efi can be specified with a relative path. That's
because the image we're executing is interpreted by the EFI shell,
which understands relative paths, whereas the rest of the command line
is passed to bzImage.efi.
Computing file changes ...
