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    SubjectRe: [PATCH] Fix initramfs size calculation
    On Wed, Aug 25, 2010 at 05:57:12PM +0200, Michael Holzheu wrote:
    > The size of a built-in initramfs is calculated in init/initramfs.c by
    > "__initramfs_end - __initramfs_start". Those symbols are defined in the
    > linker script include/asm-generic/vmlinux.lds.h:
    >
    > #define INIT_RAM_FS \
    > . = ALIGN(PAGE_SIZE); \
    > VMLINUX_SYMBOL(__initramfs_start) = .; \
    > *(.init.ramfs) \
    > VMLINUX_SYMBOL(__initramfs_end) = .;
    >
    > If the initramfs file has an odd number of bytes, the "__initramfs_end"
    > symbol points to an odd address, for example, the symbols in the System.map
    > might look like:
    >
    > 0000000000572000 T __initramfs_start
    > 00000000005bcd05 T __initramfs_end <-- odd address
    >
    > At least on s390 this is a problem:

    Another way to fix this could be to align . to an even
    address like this:
    > #define INIT_RAM_FS \
    > . = ALIGN(PAGE_SIZE); \
    > VMLINUX_SYMBOL(__initramfs_start) = .; \
    > *(.init.ramfs) \
    . = ALIGN(32); \
    > VMLINUX_SYMBOL(__initramfs_end) = .;
    >

    32 was selected as this is what we will introduce as the default
    alignment in linker scripts anyway.

    This I guess is a problem we have had some time and a minimal fix is
    easier to have backported by the stable team.

    > The patch also restructures the "usr/initramfs_data.xxx.S" files to use a
    > common macro that includes the (compressed) initramfs file and calculates
    > the __initramfs_size.
    I like this anyway. Could you do this as a separate patch?

    Sam


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