[PATCH 6/8] cmd: efidebug: simplify printing GUIDs

[Heinrich Schuchardt]

On 1/24/22 08:23, AKASHI Takahiro wrote:
> On Fri, Jan 21, 2022 at 05:03:03PM +0100, Heinrich Schuchardt wrote:
>> On 1/21/22 16:20, Simon Glass wrote:
>>> Hi Heinrich,
>>>
>>> On Sun, 16 Jan 2022 at 08:14, Heinrich Schuchardt
>>> <heinrich.schuchardt at canonical.com> wrote:
>>>>
>>>> Use "%pS" to print text representations of GUIDs.
>>>>
>>>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
>>>> ---
>>>>    cmd/efidebug.c         | 160 ++---------------------------------------
>>>>    include/efi_api.h      |   8 +++
>>>>    include/efi_dt_fixup.h |   4 --
>>>>    include/efi_rng.h      |   4 --
>>>>    lib/uuid.c             | 116 ++++++++++++++++++++++++++++++
>>>>    5 files changed, 128 insertions(+), 164 deletions(-)
>>>>
>>>
>>> Does this blow up the image size? These strings only in the debug side before.
>>
>> It was to avoid image size increase that I added
>> +#ifdef CONFIG_CMD_EFIDEBUG
>>
>>>
>>> Having said that, I would much rather see a string than a guid, which
>>> I consider to be little more than an obfuscation.
>>
>> That was my motivation. When debugging a boot failure I set DEBUG in
>> lib/efi_loader/efi_boottime.c and reading GUIDs in the debug output was not
>> helpful.
>
> But setting DEBUG in efi_boottime.c doesn't lead to CONFIG_CMD_EFIDEBUG
> being on in uuid.c. Do we want to have a more direct CONFIG?

We could use CONFIG_LOGLEVEL >= LOGL_DEBUG because once that loglevel is
set you can use the log command to log one of the EFI related functions.

Overall the EFI debugging requires rethinking:

If you simply add '#define DEFINE 1' to the top of
lib/efi_loader/efi_boottime your screen will be flooded by function
calls related to timer events. Probably those high frequency events
should use LOGL_DEBUG_IO.

Best regards

Heinrich

>
> -Takahiro Akashi
>
>> Best regards
>>
>> Heinrich
>>
>>>
>>> Regards,
>>> Simon