On Wed, 31 May, at 10:12:41AM, Jiri Slaby wrote:
> efi_pe_entry body is somehow squashed into startup_64. In the old days,
> we forced startup_64 to start at offset 0x200 and efi_pe_entry to start
> at 0x210. But this requirement was removed in 99f857db8857 ("x86, build:
> Dynamically find entry points in compressed startup code") long time
> ago.
>
> The way it is now makes the code less readable and illogical. And given
> we can now safely extract the inlined efi_pe_entry body from
> startup_64 into a separate function, we do so.
>
> We also annotate the function appropriatelly by ENTRY+ENDPROC.
>
> ABI offsets are preserved:
> 0000000000000000 T startup_32
> 0000000000000200 T startup_64
> 0000000000000390 T efi64_stub_entry
>
> On the top-level, it looked like:
> .org 0x200
> ENTRY(startup_64)
> #ifdef CONFIG_EFI_STUB ; start of inlined
> jmp preferred_addr
> GLOBAL(efi_pe_entry)
> ... ; a lot of assembly (efi_pe_entry)
> leaq preferred_addr(%rax), %rax
> jmp *%rax
> preferred_addr:
> #endif ; end of inlined
> ... ; a lot of assembly (startup_64)
> ENDPROC(startup_64)
>
> And it is converted into:
> .org 0x200
> ENTRY(startup_64)
> ... ; a lot of assembly (startup_64)
> ENDPROC(startup_64)
>
> #ifdef CONFIG_EFI_STUB
> ENTRY(efi_pe_entry)
> ... ; a lot of assembly (efi_pe_entry)
> leaq startup_64(%rax), %rax
> jmp *%rax
> ENDPROC(efi_pe_entry)
> #endif
>
> Signed-off-by: Jiri Slaby <jsl...@suse.cz>
> Cc: "H. Peter Anvin" <h...@zytor.com>
> Cc: Thomas Gleixner <t...@linutronix.de>
> Cc: Ingo Molnar <mi...@redhat.com>
> Cc: <x...@kernel.org>
> Cc: David Woodhouse <dw...@infradead.org>
> Cc: Matt Fleming <m...@codeblueprint.co.uk>
> ---
> arch/x86/boot/compressed/head_64.S | 112
> ++++++++++++++++++-------------------
> 1 file changed, 53 insertions(+), 59 deletions(-)
Reviewed-by: Matt Fleming <m...@codeblueprint.co.uk>
