Commit Graph

6 Commits

Author SHA1 Message Date
Mark Rutland
0bcaa9040d efi: efi-stub: notify on DTB absence
In the absence of a DTB configuration table, the EFI stub will happily
continue attempting to boot a kernel, despite the fact that this kernel
may not function without a description of the hardware. In this case, as
with a typo'd "dtb=" option (e.g. "dbt=") or many other possible
failures, the only output seen by the user will be the rather terse
output from the EFI stub:

EFI stub: Booting Linux Kernel...

To aid those attempting to debug such failures, this patch adds a notice
when no DTB is found, making the output more helpful:

EFI stub: Booting Linux Kernel...
EFI stub: Generating empty DTB

Additionally, a positive acknowledgement is added when a user-specified
DTB is in use:

EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from command line

Similarly, a positive acknowledgement is added when a DTB from a
configuration table is in use:

EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from configuration table

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-11-05 09:03:34 +01:00
Matt Fleming
75b128573b Merge branch 'next' into efi-next-merge
Conflicts:
	arch/x86/boot/compressed/eboot.c
2014-10-03 22:15:56 +01:00
Matt Fleming
5a17dae422 efi: Add efi= parameter parsing to the EFI boot stub
We need a way to customize the behaviour of the EFI boot stub, in
particular, we need a way to disable the "chunking" workaround, used
when reading files from the EFI System Partition.

One of my machines doesn't cope well when reading files in 1MB chunks to
a buffer above the 4GB mark - it appears that the "chunking" bug
workaround triggers another firmware bug. This was only discovered with
commit 4bf7111f50 ("x86/efi: Support initrd loaded above 4G"), and
that commit is perfectly valid. The symptom I observed was a corrupt
initrd rather than any kind of crash.

efi= is now used to specify EFI parameters in two very different
execution environments, the EFI boot stub and during kernel boot.

There is also a slight performance optimization by enabling efi=nochunk,
but that's offset by the fact that you're more likely to run into
firmware issues, at least on x86. This is the rationale behind leaving
the workaround enabled by default.

Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're
using the current value of 1MB.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03 18:40:57 +01:00
Mark Salter
0ceac9e094 efi/arm64: Fix fdt-related memory reservation
Commit 86c8b27a01:
 "arm64: ignore DT memreserve entries when booting in UEFI mode

prevents early_init_fdt_scan_reserved_mem() from being called for
arm64 kernels booting via UEFI. This was done because the kernel
will use the UEFI memory map to determine reserved memory regions.
That approach has problems in that early_init_fdt_scan_reserved_mem()
also reserves the FDT itself and any node-specific reserved memory.
By chance of some kernel configs, the FDT may be overwritten before
it can be unflattened and the kernel will fail to boot. More subtle
problems will result if the FDT has node specific reserved memory
which is not really reserved.

This patch has the UEFI stub remove the memory reserve map entries
from the FDT as it does with the memory nodes. This allows
early_init_fdt_scan_reserved_mem() to be called unconditionally
so that the other needed reservations are made.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-09-09 07:51:09 +01:00
Linus Torvalds
76f09aa464 Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI changes from Ingo Molnar:
 "Main changes in this cycle are:

   - arm64 efi stub fixes, preservation of FP/SIMD registers across
     firmware calls, and conversion of the EFI stub code into a static
     library - Ard Biesheuvel

   - Xen EFI support - Daniel Kiper

   - Support for autoloading the efivars driver - Lee, Chun-Yi

   - Use the PE/COFF headers in the x86 EFI boot stub to request that
     the stub be loaded with CONFIG_PHYSICAL_ALIGN alignment - Michael
     Brown

   - Consolidate all the x86 EFI quirks into one file - Saurabh Tangri

   - Additional error logging in x86 EFI boot stub - Ulf Winkelvos

   - Support loading initrd above 4G in EFI boot stub - Yinghai Lu

   - EFI reboot patches for ACPI hardware reduced platforms"

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  efi/arm64: Handle missing virtual mapping for UEFI System Table
  arch/x86/xen: Silence compiler warnings
  xen: Silence compiler warnings
  x86/efi: Request desired alignment via the PE/COFF headers
  x86/efi: Add better error logging to EFI boot stub
  efi: Autoload efivars
  efi: Update stale locking comment for struct efivars
  arch/x86: Remove efi_set_rtc_mmss()
  arch/x86: Replace plain strings with constants
  xen: Put EFI machinery in place
  xen: Define EFI related stuff
  arch/x86: Remove redundant set_bit(EFI_MEMMAP) call
  arch/x86: Remove redundant set_bit(EFI_SYSTEM_TABLES) call
  efi: Introduce EFI_PARAVIRT flag
  arch/x86: Do not access EFI memory map if it is not available
  efi: Use early_mem*() instead of early_io*()
  arch/ia64: Define early_memunmap()
  x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
  efi/reboot: Allow powering off machines using EFI
  efi/reboot: Add generic wrapper around EfiResetSystem()
  ...
2014-08-04 17:13:50 -07:00
Ard Biesheuvel
f4f75ad574 efi: efistub: Convert into static library
This patch changes both x86 and arm64 efistub implementations
from #including shared .c files under drivers/firmware/efi to
building shared code as a static library.

The x86 code uses a stub built into the boot executable which
uncompresses the kernel at boot time. In this case, the library is
linked into the decompressor.

In the arm64 case, the stub is part of the kernel proper so the library
is linked into the kernel proper as well.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-18 21:22:19 +01:00