On Mon, Sep 6, 2021 at 10:15 PM Helge Deller <deller@xxxxxx> wrote:
> On 9/6/21 12:54 PM, Arnd Bergmann wrote:
> > Ideally however you would
> > change the linker script to insert a
> >
> > . = ALIGN(4);
> >
> > before the output to make the variable properly aligned according to
> > the ABI. See 'git log arch/arm/kernel/vmlinux.lds.S' for a long history
> > of alignment changes we did there.
>
> This here is a special case and it's not just parisc.
> This happens when the linux kernel gets compressed, and at the end of
> the compressed file bzip/gzip/lz4 and such gets added the size of the
> compressed file.
> See in generic Makefile scripts/Makefile.lib, line 392ff.
> During make then this happens (for lz4 compression):
> { cat arch/parisc/boot/compressed/vmlinux.bin | lz4c -l -c1 stdin stdout; printf \\350\\044\\232\\000; } > arch/parisc/boot/compressed/vmlinux.bin.lz4
> which is then later added as binary input to the linker to generate final file.
Ok, I see. It looks like x86 rewrote this part in 02a884c0fe7e ("x86, boot:
determine compressed code offset at compile time") to parse the size
at compile time, but recreating this on parisc and the other architectures
that have the vmlinux.scr linker script would be a lot of work for little
benefit.
Arnd
