diff mbox series

[v4,1/1] fitimage: Add support for custom compatible string via optional parameter

Message ID 20250930065117.2625998-2-kavinaya@qti.qualcomm.com
State New
Headers show
Series Add support for custom compatible string via optional parameter | expand

Commit Message

Kavinaya S Sept. 30, 2025, 6:51 a.m. UTC 
Currently, fitimage_emit_section_dtb() always derives the 'compatible'
property from the DTB using fdtget when add_compatible=True. In some
cases, it is desirable to override this with a custom compatible string
defined in the build metadata.

1.The compatible string format that we require is different from what
  dynamic generation allows. The format that we rely on is:

   compatible = "qcom,<SoC>[-<soc_version>][-<foundry_id>]-<board>
   [/<subtype>][-<pmic>][-<board_version>]"

  This structure enables precise identification of the appropriate DTB
  for each board variant.

2.As in the upstream kernel Makefile for QCOM platforms
(https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/qcom/Makefile ), overlays are used to generate composite DTBs:

   dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-rb3gen2.dtb
   qcs6490-rb3gen2-vision-mezzanine-dtbs := qcs6490-rb3gen2.dtb qcs6490-rb3gen2-vision-mezzanine.dtbo
   qcs6490-rb3gen2-industrial-mezzanine-dtbs := qcs6490-rb3gen2.dtb qcs6490-rb3gen2-industrial-mezzanine.dtbo

   In the above cases, the base DTB remains the same, but the
   overlays differ. In such cases,we cannot assign unique compatible
   strings to these variants.

This patch introduces an optional 'custom_compatible' parameter to
fitimage_emit_section_dtb(). When provided, this value is used instead
of extracting from the DTB. The parameter accepts either a space-
separated string or a list of strings, which are split into the
compatible array for the ITS node.

This patch also updates test_get_compatible_from_dtb() to check that the
FIT_DTB_COMPATIBLE_OVERRIDE_<dtb>.dtb variable is applied correctly.

Suggested-By: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Kavinaya S <kavinaya@qti.qualcomm.com>
---
 meta/classes-recipe/kernel-fit-image.bbclass |  3 ++-
 meta/conf/image-fitimage.conf                |  6 ++++++
 meta/lib/oe/fitimage.py                      | 12 +++++++++---
 meta/lib/oeqa/selftest/cases/fitimage.py     |  8 ++++++++
 4 files changed, 25 insertions(+), 4 deletions(-)

Comments

Alexander Kanavin Sept. 30, 2025, 11:01 a.m. UTC | #1 
On Tue, 30 Sept 2025 at 08:51, Kavinaya S <kavinaya@qti.qualcomm.com> wrote:

> --- a/meta/lib/oeqa/selftest/cases/fitimage.py
> +++ b/meta/lib/oeqa/selftest/cases/fitimage.py
> @@ -778,6 +778,8 @@ FIT_CONF_PREFIX = "foo-"
>          1. bitbake bbb-dtbs-as-ext
>          2. Check if symlink_points_below returns the path to the DTB
>          3. Check if the expected compatible string is found by get_compatible_from_dtb()
> +        4. Verify that a custom compatible string can be passed
> +
>          """
>          DTB_RECIPE = "bbb-dtbs-as-ext"
>          DTB_FILE = "am335x-bonegreen-ext.dtb"
> @@ -788,6 +790,7 @@ FIT_CONF_PREFIX = "foo-"
>          config = """
>  DISTRO = "poky"
>  MACHINE = "beaglebone-yocto"
> +FIT_DTB_COMPATIBLE_OVERRIDE_am335x-bonegreen-ext.dtb = "custom,board custom,variant"
>  """
>          self.write_config(config)
>
> @@ -819,6 +822,11 @@ MACHINE = "beaglebone-yocto"
>          # The alias is a symlink, therefore the compatible string is equal
>          self.assertEqual(comp_alias, comp)
>
> +        # Test custom compatible string override via FIT_DTB_COMPATIBLE_OVERRIDE variable
> +        custom_override = get_bb_var("FIT_DTB_COMPATIBLE_OVERRIDE_am335x-bonegreen-ext.dtb", DTB_RECIPE)
> +        self.assertTrue(custom_override)
> +        self.assertEqual(str(custom_override).split(), ["custom,board", "custom,variant"])
> +

I took a closer look at the selftest, and actually this is not right.
This modifies a test that is intended specifically for testing
get_compatible_from_dtb() (so it's not the right test to modify), and
it doesn't check that passing in a custom compatible will result in a
correct .its output, it only checks that getting a bitbake variable
(after it's been set) works ok - not a useful check.

Rather, I think you should take a look at test_fitimage_py_default()
and test_fitimage_py_default_dtb(), and add one more test that sets
the custom compatible. Adrian could probably give more authoritative
advice.

Alex
diff mbox series

Patch

diff --git a/meta/classes-recipe/kernel-fit-image.bbclass b/meta/classes-recipe/kernel-fit-image.bbclass
index f04aee1807..de0f3c332e 100644
--- a/meta/classes-recipe/kernel-fit-image.bbclass
+++ b/meta/classes-recipe/kernel-fit-image.bbclass
@@ -84,8 +84,9 @@  python do_compile() {
 
             # Copy the dtb or dtbo file into the FIT image assembly directory
             shutil.copyfile(os.path.join(kernel_deploydir, dtb_name), dtb_name)
+            custom_compatible_str = d.getVar(f"FIT_DTB_COMPATIBLE_OVERRIDE_{dtb_name}") or None
             root_node.fitimage_emit_section_dtb(dtb_name, dtb_name,
-                d.getVar("UBOOT_DTB_LOADADDRESS"), d.getVar("UBOOT_DTBO_LOADADDRESS"))
+                d.getVar("UBOOT_DTB_LOADADDRESS"), d.getVar("UBOOT_DTBO_LOADADDRESS"), True, custom_compatible=custom_compatible_str)
 
     if external_kernel_devicetree:
         # iterate over all .dtb and .dtbo files in the external kernel devicetree directory
diff --git a/meta/conf/image-fitimage.conf b/meta/conf/image-fitimage.conf
index 090ee148f4..f685948c3b 100644
--- a/meta/conf/image-fitimage.conf
+++ b/meta/conf/image-fitimage.conf
@@ -65,3 +65,9 @@  FIT_ADDRESS_CELLS ?= "1"
 # Machine configurations needing such a script file should include it in the
 # SRC_URI of the kernel recipe and set the FIT_UBOOT_ENV parameter.
 FIT_UBOOT_ENV ?= ""
+
+
+# To override the DTB 'compatible' string in the FIT image, add in your
+# machine.conf or local.conf:
+#
+#  FIT_DTB_COMPATIBLE_OVERRIDE_qcs6490-rb3gen2-vision-mezzanine.dtb = "qcom,qcs6490-rb-subtype2"
diff --git a/meta/lib/oe/fitimage.py b/meta/lib/oe/fitimage.py
index f303799155..54baba28bc 100644
--- a/meta/lib/oe/fitimage.py
+++ b/meta/lib/oe/fitimage.py
@@ -289,7 +289,7 @@  class ItsNodeRootKernel(ItsNode):
         self._kernel = kernel_node
 
     def fitimage_emit_section_dtb(self, dtb_id, dtb_path, dtb_loadaddress=None,
-                                  dtbo_loadaddress=None, add_compatible=False):
+                                  dtbo_loadaddress=None, add_compatible=False, custom_compatible=None):
         """Emit the fitImage ITS DTB section"""
         load=None
         dtb_ext = os.path.splitext(dtb_path)[1]
@@ -309,7 +309,10 @@  class ItsNodeRootKernel(ItsNode):
         # Preserve the DTB's compatible string to be added to the configuration node
         compatible = None
         if add_compatible:
-            compatible = get_compatible_from_dtb(dtb_path)
+            if custom_compatible:
+                compatible = str(custom_compatible).split()
+            else:
+                compatible = get_compatible_from_dtb(dtb_path)
 
         dtb_node = self.its_add_node_dtb(
             "fdt-" + dtb_id,
@@ -326,7 +329,10 @@  class ItsNodeRootKernel(ItsNode):
         # Preserve the DTB's compatible string to be added to the configuration node
         compatible = None
         if add_compatible:
-            compatible = get_compatible_from_dtb(dtb_path)
+            if custom_compatible:
+                compatible = str(custom_compatible).split()
+            else:
+                compatible = get_compatible_from_dtb(dtb_path)
 
         dtb_id = os.path.basename(dtb_path)
         dtb_alias_node = ItsNodeDtbAlias("fdt-" + dtb_id, dtb_alias_id, compatible)
diff --git a/meta/lib/oeqa/selftest/cases/fitimage.py b/meta/lib/oeqa/selftest/cases/fitimage.py
index 3c40857747..1ca55a7706 100644
--- a/meta/lib/oeqa/selftest/cases/fitimage.py
+++ b/meta/lib/oeqa/selftest/cases/fitimage.py
@@ -778,6 +778,8 @@  FIT_CONF_PREFIX = "foo-"
         1. bitbake bbb-dtbs-as-ext
         2. Check if symlink_points_below returns the path to the DTB
         3. Check if the expected compatible string is found by get_compatible_from_dtb()
+        4. Verify that a custom compatible string can be passed
+
         """
         DTB_RECIPE = "bbb-dtbs-as-ext"
         DTB_FILE = "am335x-bonegreen-ext.dtb"
@@ -788,6 +790,7 @@  FIT_CONF_PREFIX = "foo-"
         config = """
 DISTRO = "poky"
 MACHINE = "beaglebone-yocto"
+FIT_DTB_COMPATIBLE_OVERRIDE_am335x-bonegreen-ext.dtb = "custom,board custom,variant"
 """
         self.write_config(config)
 
@@ -819,6 +822,11 @@  MACHINE = "beaglebone-yocto"
         # The alias is a symlink, therefore the compatible string is equal
         self.assertEqual(comp_alias, comp)
 
+        # Test custom compatible string override via FIT_DTB_COMPATIBLE_OVERRIDE variable
+        custom_override = get_bb_var("FIT_DTB_COMPATIBLE_OVERRIDE_am335x-bonegreen-ext.dtb", DTB_RECIPE)
+        self.assertTrue(custom_override)
+        self.assertEqual(str(custom_override).split(), ["custom,board", "custom,variant"])
+
     def test_fit_image_ext_dtb_dtbo(self):
         """
         Summary:     Check if FIT image and Image Tree Source (its) are created correctly.