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

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

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.

About the other IMAGE_FSTYPES_DEBUGFS references, it does look like it should
add IMAGE_FSTYPES_DEBUGFS to IMAGE_FSTYPES, but it didn't when I tested it, so
I'm not entirely sure :/ Maybe this is a problem in oecore?

Cheers,
Antonin

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