Re: [GRUB2 PATCH v3 2/4] multiboot2: Add tags used to pass ImageHandle to loaded image

[Vladimir 'phcoder' Serbinenko]

On Wednesday, March 2, 2016, Daniel Kiper <address@hidden> wrote:
> Add tags used to pass ImageHandle to loaded image if requested.
> It is used by at least ExitBootServices() function.
>
> Signed-off-by: Daniel Kiper <address@hidden>
> ---
> v3 - suggestions/fixes:
>    - mbi EFI related stuff size calculation
>      should depend on target architecture
>      (suggested by Konrad Rzeszutek Wilk),
>    - use plain type instead of pointer
>      dereference as sizeof() argument
>      (suggested by Konrad Rzeszutek Wilk),
>    - improve commit message
>      (suggested by Konrad Rzeszutek Wilk).
> ---
>  grub-core/loader/multiboot_mbi2.c |   50 ++++++++++++++++++++++++++++++-------
>  include/multiboot2.h              |   16 ++++++++++++
>  2 files changed, 57 insertions(+), 9 deletions(-)
>
> diff --git a/grub-core/loader/multiboot_mbi2.c b/grub-core/loader/multiboot_mbi2.c
> index a3dca90..7591edc 100644
> --- a/grub-core/loader/multiboot_mbi2.c
> +++ b/grub-core/loader/multiboot_mbi2.c
> @@ -172,6 +172,8 @@ grub_multiboot_load (grub_file_t file, const char *filename)
>               case MULTIBOOT_TAG_TYPE_NETWORK:
>               case MULTIBOOT_TAG_TYPE_EFI_MMAP:
>               case MULTIBOOT_TAG_TYPE_EFI_BS:
> +             case MULTIBOOT_TAG_TYPE_EFI32_IH:
> +             case MULTIBOOT_TAG_TYPE_EFI64_IH:
>                 break;
>
>               default:
> @@ -407,16 +409,22 @@ grub_multiboot_get_mbi_size (void)
>                  + grub_get_multiboot_mmap_count ()
>                  * sizeof (struct multiboot_mmap_entry)), MULTIBOOT_TAG_ALIGN)
>      + ALIGN_UP (sizeof (struct multiboot_tag_framebuffer), MULTIBOOT_TAG_ALIGN)
> +#ifdef GRUB_MACHINE_EFI
> +#ifdef __i386__
>      + ALIGN_UP (sizeof (struct multiboot_tag_efi32), MULTIBOOT_TAG_ALIGN)
> +    + ALIGN_UP (sizeof (struct multiboot_tag_efi32_ih), MULTIBOOT_TAG_ALIGN)
> +#endif
> +#ifdef __x86_64__
>      + ALIGN_UP (sizeof (struct multiboot_tag_efi64), MULTIBOOT_TAG_ALIGN)
> +    + ALIGN_UP (sizeof (struct multiboot_tag_efi64_ih), MULTIBOOT_TAG_ALIGN)
> +#endif
> +    + ALIGN_UP (sizeof (struct multiboot_tag_efi_mmap)
> +               + efi_mmap_size, MULTIBOOT_TAG_ALIGN)
> +#endif

It doesn't need to be exact. It's just an upper bound. Feel free to simplify knowing this, removing few #ifdef. 

>      + ALIGN_UP (sizeof (struct multiboot_tag_old_acpi)
>                 + sizeof (struct grub_acpi_rsdp_v10), MULTIBOOT_TAG_ALIGN)
>      + acpiv2_size ()
>      + net_size ()
> -#ifdef GRUB_MACHINE_EFI
> -    + ALIGN_UP (sizeof (struct multiboot_tag_efi_mmap)
> -               + efi_mmap_size, MULTIBOOT_TAG_ALIGN)
> -#endif
>      + sizeof (struct multiboot_tag_vbe) + MULTIBOOT_TAG_ALIGN - 1
>      + sizeof (struct multiboot_tag_apm) + MULTIBOOT_TAG_ALIGN - 1;
>  }
> @@ -907,11 +915,35 @@ grub_multiboot_make_mbi (grub_uint32_t *target)
>
>    if (keep_bs)
>      {
> -      struct multiboot_tag *tag = (struct multiboot_tag *) ptrorig;
> -      tag->type = MULTIBOOT_TAG_TYPE_EFI_BS;
> -      tag->size = sizeof (struct multiboot_tag);
> -      ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> -       / sizeof (grub_properly_aligned_t);
> +      {
> +       struct multiboot_tag *tag = (struct multiboot_tag *) ptrorig;
> +       tag->type = MULTIBOOT_TAG_TYPE_EFI_BS;
> +       tag->size = sizeof (struct multiboot_tag);
> +       ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> +         / sizeof (grub_properly_aligned_t);
> +      }
> +
> +#ifdef __i386__
> +      {
> +       struct multiboot_tag_efi32_ih *tag = (struct multiboot_tag_efi32_ih *) ptrorig;
> +       tag->type = MULTIBOOT_TAG_TYPE_EFI32_IH;
> +       tag->size = sizeof (struct multiboot_tag_efi32_ih);
> +       tag->pointer = (grub_addr_t) grub_efi_image_handle;
> +       ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> +         / sizeof (grub_properly_aligned_t);
> +      }
> +#endif
> +
> +#ifdef __x86_64__
> +      {
> +       struct multiboot_tag_efi64_ih *tag = (struct multiboot_tag_efi64_ih *) ptrorig;
> +       tag->type = MULTIBOOT_TAG_TYPE_EFI64_IH;
> +       tag->size = sizeof (struct multiboot_tag_efi64_ih);
> +       tag->pointer = (grub_addr_t) grub_efi_image_handle;
> +       ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> +         / sizeof (grub_properly_aligned_t);
> +      }
> +#endif
>      }
>  #endif
>
> diff --git a/include/multiboot2.h b/include/multiboot2.h
> index d96aa40..36a174f 100644
> --- a/include/multiboot2.h
> +++ b/include/multiboot2.h
> @@ -60,6 +60,8 @@
>  #define MULTIBOOT_TAG_TYPE_NETWORK           16
>  #define MULTIBOOT_TAG_TYPE_EFI_MMAP          17
>  #define MULTIBOOT_TAG_TYPE_EFI_BS            18
> +#define MULTIBOOT_TAG_TYPE_EFI32_IH          19
> +#define MULTIBOOT_TAG_TYPE_EFI64_IH          20

Is there a followup to define those in texi doc as well? 

>  #define MULTIBOOT_HEADER_TAG_END  0
>  #define MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST  1
> @@ -371,6 +373,20 @@ struct multiboot_tag_efi_mmap
>    multiboot_uint8_t efi_mmap[0];
>  };
>
> +struct multiboot_tag_efi32_ih
> +{
> +  multiboot_uint32_t type;
> +  multiboot_uint32_t size;
> +  multiboot_uint32_t pointer;
> +};
> +
> +struct multiboot_tag_efi64_ih
> +{
> +  multiboot_uint32_t type;
> +  multiboot_uint32_t size;
> +  multiboot_uint64_t pointer;
> +};
> +
>  #endif /* ! ASM_FILE */
>
>  #endif /* ! MULTIBOOT_HEADER */
> --
> 1.7.10.4


-- 
Regards
Vladimir 'phcoder' Serbinenko