On Tue, Sep 15, 2015 at 04:41:18PM +0100, Suzuki K. Poulose wrote: > From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > > This patch adds the page size to the arm64 kernel image header > so that one can infer the PAGESIZE used by the kernel. This will > be helpful to diagnose failures to boot the kernel with page size > not supported by the CPU. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > --- > Documentation/arm64/booting.txt | 7 ++++++- > arch/arm64/kernel/image.h | 5 ++++- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt > index 7d9d3c2..aaf6d77 100644 > --- a/Documentation/arm64/booting.txt > +++ b/Documentation/arm64/booting.txt > @@ -104,7 +104,12 @@ Header notes: > - The flags field (introduced in v3.17) is a little-endian 64-bit field > composed as follows: > Bit 0: Kernel endianness. 1 if BE, 0 if LE. > - Bits 1-63: Reserved. > + Bit 1-2: Kernel Page size. > + 0 - Unspecified. > + 1 - 4K > + 2 - 16K > + 3 - 64K > + Bits 3-63: Reserved. > > - When image_size is zero, a bootloader should attempt to keep as much > memory as possible free for use by the kernel immediately after the > diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h > index 8fae075..73b736c 100644 > --- a/arch/arm64/kernel/image.h > +++ b/arch/arm64/kernel/image.h > @@ -47,7 +47,10 @@ > #define __HEAD_FLAG_BE 0 > #endif > > -#define __HEAD_FLAGS (__HEAD_FLAG_BE << 0) > +#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) > + > +#define __HEAD_FLAGS (__HEAD_FLAG_BE << 0) | \ > + (__HEAD_FLAG_PAGE_SIZE << 1) > > /* > * These will output as part of the Image header, which should be little-endian > -- > 1.7.9.5 > Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
