Re: Grub get and set efi variables

[Mat Troi <mattroisang@gmail.com>]

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For a specific project implementation, I need to be able to write and read
one EFI variable during boot only.  So I have written a grub command to do
just that.  But the issue is with setting these attributes to the variable
(GRUB_EFI_VARIABLE_NON_VOLATILE, GRUB_EFI_VARIABLE_BOOTSERVICE_ACCESS), I
am not able to modify it during boot on some platform.  Since this is so
specific, I am wondering if anyone has seen similar issue?

On Fri, Nov 13, 2015 at 8:03 PM, Andrei Borzenkov <arvidjaar@gmail.com>
wrote:

> 13.11.2015 22:42, Ignat Korchagin пишет:
>
>> +static enum efi_var_type
>>>>> +parse_efi_var_type (const char *type)
>>>>> +{
>>>>> +  if (!grub_strncmp (type, "string", sizeof("string")))
>>>>> +    return EFI_VAR_STRING;
>>>>> +
>>>>>
>>>>
>>>>
>>>> I think this should be "ascii" or "utf8". "string" is too ambiguous in
>>>> UEFI
>>>> environment, it can also mean sequence of UCS-2 characters.
>>>>
>>> I'm still not sure how exactly GRUB + UEFI interprets "raw buffers"
>>> when printing. Maybe, to avoid confusion, it might be better to
>>> completely remove this option. Basically, you do not want to interpret
>>> raw buffers as strings. For best compatibility "hex" mode should be
>>> promoted, I guess. What do you think?
>>>
>> Checked again the UEFI spec. For globally defined variables which are
>> strings they specify ASCII. So if we leave this option, ascii is the
>> best name.
>>
>>
> What about
>
>   - ascii - print ASCII characters verbatim, escape non-ASCII in usual way
> (similar to "od -c")
>
>   - raw - simply put raw variable without any interpretation.
>
> This is better aligned with argument describing output formatting rather
> than attempting to "type" variable.
>
> Alternative (or in addition to) ascii - dump which prints usual pretty hex
> dump of content (hexdump -C). This is handy to interactively look at
> variable content.
>
> Or, and change name from --type to --format :)
>
>
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