Re: [docs] [PATCH] dev-manual/debugging: improve gdbserver debugfs docs

["Antonin Godard" <antonin.godard@bootlin.com>]

On Tue Oct 22, 2024 at 2:17 PM CEST, Quentin Schulz wrote:
> Hi Antonin,
>
> On 10/22/24 2:10 PM, Antonin Godard wrote:
>> Hi Quentin,
>>
>> On Tue Oct 22, 2024 at 1:57 PM CEST, Quentin Schulz via lists.yoctoproject.org wrote:
>>>> 1. Make it clear that IMAGE_FSTYPES has to contain tar.bz2
>>>
>>> Yes, but isn't it done automatically if IMAGE_FSTYPES_DEBUGFS and
>>> IMAGE_GEN_DEBUGFS are set?
>>>
>>> We have a selftest here: meta/lib/oeqa/selftest/cases/gdbserver.py that
>>> doesn't seem to be adding tar.bz2 to IMAGE_FSTYPES, so I assume it's fine?
>>
>> I think it might be because qemu.inc adds it by default (not a oeqa expert
>> though :) ). Here's what I have by default with qemu:
>>
>> ```
>> $ bitbake-getvar IMAGE_FSTYPES -r core-image-minimal
>> #
>> # $IMAGE_FSTYPES [3 operations]
>> #   append /build/../work/openembedded-core/meta/conf/machine/include/qemu.inc:18
>> #     "tar.bz2 ext4"
>> #   set /build/../work/openembedded-core/meta/conf/documentation.conf:215
>> #     [doc] "Formats of root filesystem images that you want to have created."
>> #   set? /build/../work/openembedded-core/meta/conf/bitbake.conf:844
>> #     "tar.gz"
>> # pre-expansion value:
>> #   " tar.bz2 ext4"
>> IMAGE_FSTYPES=" tar.bz2 ext4"
>> ```
>>
>>> meta/classes-recipe/image.bbclass and
>>> meta/classes-recipe/image_types.bbclass are the only places where
>>> IMAGE_FSTYPES_DEBUGFS is actually used, and it seems that we're adding
>>> the content of IMAGE_FSTYPES_DEBUGFS to those of IMAGE_FSTYPES if I am
>>> not misreading it?
>>
>> In image_types, the following:
>>
>>    fstypes |= set((d.getVar('IMAGE_FSTYPES_DEBUGFS') or "").split())
>>
>> Is an union, so if tar.bz2 is not in IMAGE_FSTYPES it won't work actually.
>>
>
> It's a union, yes, but that's why it'll work :)
>
>  >>> a = set([1, 2, 3])
>  >>> b = set([3, 4, 5])
>  >>> a | b
> {1, 2, 3, 4, 5}
>  >>> c = set([5, 6, 7])
>  >>> c |= a
>  >>> c
> {1, 2, 3, 5, 6, 7}
>
> c.f. https://docs.python.org/3/library/stdtypes.html#frozenset.union

Indeed, my bad, read that too quickly. Thanks :)

Cheers,
Antonin

--
Antonin Godard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com