diff mbox series

[v3] uki.bbclass: make DTB packaging optional

Message ID 20260312125834.3046637-1-viswanath.kraleti@oss.qualcomm.com
State Under Review
Headers show
Series [v3] uki.bbclass: make DTB packaging optional | expand

Commit Message

Viswanath Kraleti March 12, 2026, 12:58 p.m. UTC 
According to the Unified Kernel Image (UKI) specification [1], including
a compiled device tree in the .dtb section of a UKI is optional. However,
the current implementation always packages device trees listed in
KERNEL_DEVICETREE into the UKI by default. This makes uki.bbclass
unsuitable for systems that rely on firmware-provided DTBs and do not
want a DTB embedded in the UKI.

Fix this by introducing a new UKI_DEVICETREE variable to control device
tree packaging. The .dtb section is now populated from UKI_DEVICETREE
instead of KERNEL_DEVICETREE. Users who do not want DTBs included in the
UKI can override UKI_DEVICETREE to an empty value from their recipes.

Update the UKI selftests accordingly, as QEMU does not provide a device
tree to embed.

[1] https://uapi-group.org/specifications/specs/unified_kernel_image/

Signed-off-by: Viswanath Kraleti <viswanath.kraleti@oss.qualcomm.com>
---
 meta/classes-recipe/uki.bbclass     | 6 ++++--
 meta/lib/oeqa/selftest/cases/uki.py | 6 ++++++
 meta/lib/oeqa/selftest/cases/wic.py | 3 +++
 3 files changed, 13 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/meta/classes-recipe/uki.bbclass b/meta/classes-recipe/uki.bbclass
index ea449540db..326697a066 100644
--- a/meta/classes-recipe/uki.bbclass
+++ b/meta/classes-recipe/uki.bbclass
@@ -80,6 +80,7 @@  UKI_CONFIG_FILE ?= "${UNPACKDIR}/uki.conf"
 UKI_FILENAME ?= "uki.efi"
 UKI_KERNEL_FILENAME ?= "${KERNEL_IMAGETYPE}"
 UKI_CMDLINE ?= "rootwait root=LABEL=root"
+UKI_DEVICETREE ?= "${KERNEL_DEVICETREE}"
 # secure boot keys and cert, needs sbsign-tools-native (meta-secure-core)
 #UKI_SB_KEY ?= ""
 #UKI_SB_CERT ?= ""
@@ -149,8 +150,9 @@  python do_uki() {
         ukify_cmd += " --cmdline='%s'" % (cmdline)
 
     # dtb
-    if d.getVar('KERNEL_DEVICETREE'):
-        for dtb in d.getVar('KERNEL_DEVICETREE').split():
+    uki_devicetree = d.getVar('UKI_DEVICETREE')
+    if uki_devicetree:
+        for dtb in uki_devicetree.split():
             # DTBs are without sub-directories in deploy_dir
             dtb_name = os.path.basename(dtb)
             dtb_path = "%s/%s" % (deploy_dir_image, dtb_name)
diff --git a/meta/lib/oeqa/selftest/cases/uki.py b/meta/lib/oeqa/selftest/cases/uki.py
index 9a1aa4e269..4265a40e9e 100644
--- a/meta/lib/oeqa/selftest/cases/uki.py
+++ b/meta/lib/oeqa/selftest/cases/uki.py
@@ -47,6 +47,9 @@  QB_DEFAULT_KERNEL = "none"
 # boot command line provided via uki, not via bootloader
 UKI_CMDLINE = "rootwait root=LABEL=root console=${KERNEL_CONSOLE}"
 
+# qemu provides the devicetree at boot, do not embed a dtb in the uki for selftests
+UKI_DEVICETREE = ""
+
 # disable kvm, breaks boot
 QEMU_USE_KVM = ""
 
@@ -106,6 +109,9 @@  QB_DEFAULT_KERNEL = "none"
 # boot command line provided via uki, not via bootloader
 UKI_CMDLINE = "rootwait root=LABEL=root console=${KERNEL_CONSOLE}"
 
+# qemu provides the devicetree at boot, do not embed a dtb in the uki for selftests
+UKI_DEVICETREE = ""
+
 # disable kvm, breaks boot
 QEMU_USE_KVM = ""
 
diff --git a/meta/lib/oeqa/selftest/cases/wic.py b/meta/lib/oeqa/selftest/cases/wic.py
index ecaee5a291..461cf8cfde 100644
--- a/meta/lib/oeqa/selftest/cases/wic.py
+++ b/meta/lib/oeqa/selftest/cases/wic.py
@@ -1556,6 +1556,9 @@  QB_DEFAULT_KERNEL = "none"
 # boot command line provided via uki, not via bootloader
 UKI_CMDLINE = "rootwait root=LABEL=root console=${KERNEL_CONSOLE}"
 
+# qemu provides the devicetree at boot, do not embed a dtb in the uki for selftests
+UKI_DEVICETREE = ""
+
 """
         self.append_config(config)
         bitbake('core-image-base ovmf')