Eric Lee / smarc-fsl-linux-kernel

13 Dec, 2011

1 commit

  • 291f36325   x86, efi: EFI boot stub support ... Browse Code »

    There is currently a large divide between kernel development and the
    development of EFI boot loaders. The idea behind this patch is to give
    the kernel developers full control over the EFI boot process. As
    H. Peter Anvin put it,

    "The 'kernel carries its own stub' approach been very successful in
    dealing with BIOS, and would make a lot of sense to me for EFI as
    well."

    This patch introduces an EFI boot stub that allows an x86 bzImage to
    be loaded and executed by EFI firmware. The bzImage appears to the
    firmware as an EFI application. Luckily there are enough free bits
    within the bzImage header so that it can masquerade as an EFI
    application, thereby coercing the EFI firmware into loading it and
    jumping to its entry point. The beauty of this masquerading approach
    is that both BIOS and EFI boot loaders can still load and run the same
    bzImage, thereby allowing a single kernel image to work in any boot
    environment.

    The EFI boot stub supports multiple initrds, but they must exist on
    the same partition as the bzImage. Command-line arguments for the
    kernel can be appended after the bzImage name when run from the EFI
    shell, e.g.

    Shell> bzImage console=ttyS0 root=/dev/sdb initrd=initrd.img

    v7:
    - Fix checkpatch warnings.

    v6:

    - Try to allocate initrd memory just below hdr->inird_addr_max.

    v5:

    - load_options_size is UTF-16, which needs dividing by 2 to convert
    to the corresponding ASCII size.

    v4:

    - Don't read more than image->load_options_size

    v3:

    - Fix following warnings when compiling CONFIG_EFI_STUB=n

    arch/x86/boot/tools/build.c: In function ‘main’:
    arch/x86/boot/tools/build.c:138:24: warning: unused variable ‘pe_header’
    arch/x86/boot/tools/build.c:138:15: warning: unused variable ‘file_sz’

    - As reported by Matthew Garrett, some Apple machines have GOPs that
    don't have hardware attached. We need to weed these out by
    searching for ones that handle the PCIIO protocol.

    - Don't allocate memory if no initrds are on cmdline
    - Don't trust image->load_options_size

    Maarten Lankhorst noted:
    - Don't strip first argument when booted from efibootmgr
    - Don't allocate too much memory for cmdline
    - Don't update cmdline_size, the kernel considers it read-only
    - Don't accept '\n' for initrd names

    v2:

    - File alignment was too large, was 8192 should be 512. Reported by
    Maarten Lankhorst on LKML.
    - Added UGA support for graphics
    - Use VIDEO_TYPE_EFI instead of hard-coded number.
    - Move linelength assignment until after we've assigned depth
    - Dynamically fill out AddressOfEntryPoint in tools/build.c
    - Don't use magic number for GDT/TSS stuff. Requested by Andi Kleen
    - The bzImage may need to be relocated as it may have been loaded at
    a high address address by the firmware. This was required to get my
    macbook booting because the firmware loaded it at 0x7cxxxxxx, which
    triggers this error in decompress_kernel(),

    if (heap > ((-__PAGE_OFFSET-(128<
    Cc: Matthew Garrett
    Tested-by: Henrik Rydberg
    Signed-off-by: Matt Fleming
    Link: http://lkml.kernel.org/r/1321383097.2657.9.camel@mfleming-mobl1.ger.corp.intel.com
    Signed-off-by: H. Peter Anvin

    Matt Fleming
     

14 Jul, 2010

1 commit

13 Jul, 2010

1 commit

  • fa97bdf92   x86, setup: Early-boot serial I/O support ... Browse Code »

    This patch adds serial I/O support to the real-mode setup (very early
    boot) printf(). It's useful for debugging boot code when running Linux
    under KVM, for example. The actual code was lifted from early printk.

    Cc: Cyrill Gorcunov
    Cc: Ingo Molnar
    Cc: Yinghai Lu
    Signed-off-by: Pekka Enberg
    LKML-Reference:
    Signed-off-by: H. Peter Anvin

    Pekka Enberg
     

20 Apr, 2008

1 commit

11 Oct, 2007

1 commit

  • 96ae6ea0b   i386: move boot ... Browse Code »

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar

    Thomas Gleixner