[syslinux] [PATCH][firmware] efi: Fix build with gnu-efi >= 3.0s

[Nigel Croxon]

Hi Matt,

Sorry for the delay in answering this patch.

The patch does not apply. The efi/efi.h file I have does not match the 
patch.  Your second file efi/vesa.c does exist in my source code.

-Nigel


On 01/08/2013 06:51 AM, Matt Fleming wrote:
> From: Matt Fleming <matt.fleming at intel.com>
>
> For x86_64 versions of gnu-efi >= 3.0s GNU_EFI_USE_MS_ABI is enabled
> which turns on the Microsoft ABI, allowing the compiler to do all the
> work of interfacing with the EFI firmware instead of jumping through
> uefi_call_wrapper().
>
> Add support to turn this on in the gnu-efi headers, otherwise we'll
> encounter undefined references to uefi_call_wrapper().
>
> This addresses the simplest case assuming a distribution's gnu-efi was
> compiled with GNU_EFI_USE_MS_ABI. If you're compiling everything from
> source and you turn off GNU_EFI_USE_MS_ABI for gnu-efi, you'll also
> need to turn it off here.
>
> Cc: H. Peter Anvin <hpa at zytor.com>
> Cc: Nigel Croxon <nigel.croxon at hp.com>
> Cc: Peter Jones <pjones at redhat.com>
> Signed-off-by: Matt Fleming <matt.fleming at intel.com>
> ---
>
> Folks, is this the correct way to fix this build breakage? I can
> certainly conceive of ways that this will break if distros start
> turning off GNU_EFI_USE_MS_ABI even though it's supported by the
> compiler, but I dunno if it's just a case of "Don't do that then".
>
> Thoughts?
>
>   efi/efi.h  | 15 +++++++++++++++
>   efi/vesa.c |  4 +---
>   2 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/efi/efi.h b/efi/efi.h
> index 6472d6a..c5bd777 100644
> --- a/efi/efi.h
> +++ b/efi/efi.h
> @@ -4,6 +4,21 @@
>   #include <core.h>
>   #include <sys/types.h>	/* needed for off_t */
>   //#include <syslinux/version.h> /* avoid redefinition of __STDC_VERSION__ */
> +
> +/*
> + * gnu-efi >= 3.0s enables GNU_EFI_USE_MS_ABI by default, which means
> + * that we must also enable it if supported by the compiler. Note that
> + * failing to enable GNU_EFI_USE_MS_ABI if gnu-efi was compiled with
> + * it on will result in undefined references to uefi_call_wrapper().
> + *
> + * The reason we don't attempt to check the version of gnu-efi we're
> + * building against is because there's no harm in turning it on for
> + * older versions - it will just be ignored.
> + */
> +#if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7))
> +  #define GNU_EFI_USE_MS_ABI 1
> +#endif
> +
>   #include <efi.h>
>   #include <efilib.h>
>   #include <efistdarg.h>
> diff --git a/efi/vesa.c b/efi/vesa.c
> index 473d3a5..38f8213 100644
> --- a/efi/vesa.c
> +++ b/efi/vesa.c
> @@ -33,9 +33,7 @@
>   #include <sys/fpu.h>
>   #include <syslinux/video.h>
>   #include <dprintf.h>
> -#include <efi.h>
> -#include <efilib.h>
> -#include <efistdarg.h>
> +#include "efi.h"
>   /* We use cp865_8x16.psf as the standard font for EFI implementation
>    * the header file below contains raw data parsed from cp865_8x16.psf
>    */
>