Re: Grub get and set efi variables

[Andrei Borzenkov <arvidjaar@gmail.com>]

02.12.2015 17:52, Ignat Korchagin пишет:
> OK. Updated patch below:
> 
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index 0cc40bb..aa7b927 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -735,6 +735,12 @@ module = {
>  };
> 
>  module = {
> +  name = efivar;
> +  efi = commands/efi/efivar.c;
> +  enable = efi;
> +};
> +
> +module = {
>    name = blocklist;
>    common = commands/blocklist.c;
>  };
> diff --git a/grub-core/commands/efi/efivar.c b/grub-core/commands/efi/efivar.c
> new file mode 100644
> index 0000000..8acd0c2
> --- /dev/null
> +++ b/grub-core/commands/efi/efivar.c
> @@ -0,0 +1,238 @@
> +/* efivar.c - Read EFI global variables. */
> +/*
> + *  GRUB  --  GRand Unified Bootloader
> + *  Copyright (C) 2015 Free Software Foundation, Inc.
> + *  Copyright (C) 2015 CloudFlare, Inc.
> + *
> + *  GRUB is free software: you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation, either version 3 of the License, or
> + *  (at your option) any later version.
> + *
> + *  GRUB is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <grub/types.h>
> +#include <grub/mm.h>
> +#include <grub/misc.h>
> +#include <grub/efi/api.h>
> +#include <grub/efi/efi.h>
> +#include <grub/extcmd.h>
> +#include <grub/env.h>
> +#include <grub/lib/hexdump.h>
> +
> +GRUB_MOD_LICENSE ("GPLv3+");
> +
> +static const struct grub_arg_option options[] = {
> +  {"format", 'f', GRUB_ARG_OPTION_OPTIONAL, N_("Parse EFI_VAR in
> specific format (hex, uint8, ascii, dump). Default: hex."),
> N_("FORMAT"), ARG_TYPE_STRING},
> +  {"set", 's', GRUB_ARG_OPTION_OPTIONAL, N_("Save parsed result to
> environment variable (does not work with dump)."), N_("ENV_VAR"),
> ARG_TYPE_STRING},
> +  {0, 0, 0, 0, 0, 0}
> +};
> +
> +enum efi_var_type
> +  {
> +    EFI_VAR_ASCII = 0,
> +    EFI_VAR_UINT8,
> +    EFI_VAR_HEX,
> +    EFI_VAR_DUMP,
> +    EFI_VAR_INVALID = -1
> +  };
> +
> +static enum efi_var_type
> +parse_efi_var_type (const char *type)
> +{
> +  if (!grub_strncmp (type, "ascii", sizeof("ascii")))
> +    return EFI_VAR_ASCII;
> +
> +  if (!grub_strncmp (type, "uint8", sizeof("uint8")))
> +    return EFI_VAR_UINT8;
> +
> +  if (!grub_strncmp (type, "hex", sizeof("hex")))
> +    return EFI_VAR_HEX;
> +
> +  if (!grub_strncmp (type, "dump", sizeof("dump")))
> +    return EFI_VAR_DUMP;
> +
> +  return EFI_VAR_INVALID;
> +}
> +

This should be grub_strcmp everywhere, there is no reason to use
grub_strncmp.
> +
> +GRUB_MOD_INIT (efivar)
> +{
> +  cmd = grub_register_extcmd ("get_efivar", grub_cmd_get_efi_var, 0,
> N_("[-f FORMAT] [-s ENV_VAR] EFI_VAR"),
> + N_("Read EFI variable and print it or save its contents to

I believe it should be "content" (without final `s') but English is not
native.

Otherwise OK from my side.

Could you also add documentation part for it?