On Wed, 31 May, at 10:12:40AM, Jiri Slaby wrote:
> efi_pe_entry body is somehow squashed into startup_32. In the old days,
> we forced startup_32 to start at offset 0x00 and efi_pe_entry to start
> at 0x10. 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_32 into a separate function, we do so and we separate it to two
> functions as they are marked already: efi_pe_entry + efi32_stub_entry.
>
> We also annotate the functions appropriatelly by ENTRY+ENDPROC.
>
> ABI offset is preserved:
> 0000 128 FUNC GLOBAL DEFAULT 6 startup_32
> 0080 60 FUNC GLOBAL DEFAULT 6 efi_pe_entry
> 00bc 68 FUNC GLOBAL DEFAULT 6 efi32_stub_entry
>
> On the top-level, it looked like:
> ENTRY(startup_32)
> #ifdef CONFIG_EFI_STUB ; start of inlined
> jmp preferred_addr
> ENTRY(efi_pe_entry)
> ... ; a lot of assembly (efi_pe_entry)
> ENTRY(efi32_stub_entry)
> ... ; a lot of assembly (efi32_stub_entry)
> leal preferred_addr(%eax), %eax
> jmp *%eax
> preferred_addr:
> #endif ; end of inlined
> ... ; a lot of assembly (startup_32)
> ENDPROC(startup_32)
>
> And it is converted into:
> ENTRY(startup_32)
> ... ; a lot of assembly (startup_32)
> ENDPROC(startup_32)
>
> #ifdef CONFIG_EFI_STUB
> ENTRY(efi_pe_entry)
> ... ; a lot of assembly (efi_pe_entry)
> ENDPROC(efi_pe_entry)
>
> ENTRY(efi32_stub_entry)
> ... ; a lot of assembly (efi32_stub_entry)
> leal startup_32(%eax), %eax
> jmp *%eax
> ENDPROC(efi32_stub_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_32.S | 129
> ++++++++++++++++++-------------------
> 1 file changed, 64 insertions(+), 65 deletions(-)
Reviewed-by: Matt Fleming <m...@codeblueprint.co.uk>
