feat(coreos-image-swupdate.bbclass): add a way to dynamically extends the

sw-description files

The COREOS_SWUPDATE_EXTENDS_FOR and COREOS_IMAGE_SWUPDATE_EXTRACLASSES
variable can now be used to configure the coreos-image-swupdate to
dynamically extends some part of the sw-description by calling some
python function

layers/meta-belden-coreos-bsp/conf/machine/include/coreos-generic-features/legacy-mbr-disk.inc

@@ -1,15 +0,0 @@
-
-# MBR disk are still supported by CoreOS, but only for legacy product
-# This ensure that efibootguard / swupdate work with MBR disk
-
-# MBR can't disk can't use partition label, but may use filesystem label
-# This will only work with an initramfs. If no initramfs is used, this will
-# have to be set to the right disk device inside the machine configuration
-# like that COREOS_PLATFORMx_ROOT = "/dev/mmcblk<DISK>p<PART>"
-COREOS_PLATFORM0_ROOT ?= "LABEL=platform0"
-COREOS_PLATFORM1_ROOT ?= "LABEL=platform1"
-
-# MBR disk can't use --part-type but can use system-id 
-WKS_PART_EFI ?= 'part --source efibootguard-efi --label efi --system-id 0xef'
-WKS_PART_EFIBOOTGUARD_A ?= 'part --source efibootguard-boot --label boot0  --sourceparams "watchdog=${EFIBOOTGUARD_TIMEOUT},revision=2,kernel=kernel0-${MACHINE}.efi;KERNEL0.EFI"'
-WKS_PART_EFIBOOTGUARD_B ?=  'part --source efibootguard-boot --label boot1 --sourceparams "watchdog=${EFIBOOTGUARD_TIMEOUT},revision=1,kernel=kernel1-${MACHINE}.efi;KERNEL1.EFI"'

layers/meta-belden-coreos/classes/coreos-image-swupdate.bbclass

@@ -38,3 +38,38 @@ python () {
 }
 
 FILESEXTRAPATHS:append := ":${COREOS_ROOT}/layers/meta-belden-coreos/files"
+
+# Space seperated list of extension points
+COREOS_SWUPDATE_EXTENDS_FOR ??= ""
+
+def coreos_swupdate_extends(d, s, key):
+    """
+    Extends the swupdate for each extension points defined by COREOS_SWUPDATE_EXTENDS_FOR
+    """
+    extends_for = d.getVar('COREOS_SWUPDATE_EXTENDS_FOR', True).replace("-", "_").split()
+
+    def kv_to_sw_description(kv):
+        swdescr = ",{\n"
+        for key, value in kv.items():
+            swdescr += f'{key} = "{value}";\n'
+        swdescr += "}\n"
+        return swdescr
+
+    text = ""
+
+    # BSP and Distro can extends the swupdate by implementing some python 
+    # function that return a list of dictionary.
+    for extension_point in extends_for:
+        try:
+            kv_list = globals()[f"coreos_swupdate_extends_{key}_for_{extension_point}"](d,s)
+        except KeyError:
+            # Don't fail if the extension is not implemented
+            pass
+        else:
+            for kv in kv_list:
+                text += kv_to_sw_description(kv)
+
+    return text
+
+COREOS_IMAGE_SWUPDATE_EXTRACLASSES ?= ""
+inherit ${COREOS_IMAGE_SWUPDATE_EXTRACLASSES}

layers/meta-belden-coreos/files/sw-description

@@ -16,6 +16,9 @@ software =
                         type = "raw";
                         sha256 = "$swupdate_get_sha256(@@PN@@-@@MACHINE@@.ext4.zst)";
                     }
+                    # Don't remove the trailing whitspace on the next line otherwise
+                    # it will not work due to a regex bug in meta-swupdate
+                    $coreos_swupdate_extends(images) 
                 );
 
                 files: (
@@ -33,6 +36,9 @@ software =
                         filesystem = "vfat";
                         sha256 = "$swupdate_get_sha256(@@COREOS_EFIBOOTGUARD_FILENAME@@)";
                     }
+                    # Don't remove the trailing whitspace on the next line otherwise
+                    # it will not work due to a regex bug in meta-swupdate
+                    $coreos_swupdate_extends(files) 
                 );
 
                 bootenv: (
@@ -49,6 +55,9 @@ software =
                             value = "C:BOOT0:KERNEL.EFI";
 
                         }
+                        # Don't remove the trailing whitspace on the next line otherwise
+                        # it will not work due to a regex bug in meta-swupdate
+                        $coreos_swupdate_extends(bootenv) 
                 );
             }
 
@@ -64,6 +73,9 @@ software =
                         type = "raw";
                         sha256 = "$swupdate_get_sha256(@@PN@@-@@MACHINE@@.ext4.zst)";
                     }
+                    # Don't remove the trailing whitspace on the next line otherwise
+                    # it will not work due to a regex bug in meta-swupdate
+                    $coreos_swupdate_extends(images) 
                 );
 
                 files: (
@@ -81,6 +93,9 @@ software =
                         filesystem = "vfat";
                         sha256 = "$swupdate_get_sha256(@@COREOS_EFIBOOTGUARD_FILENAME@@)";
                     }
+                    # Don't remove the trailing whitspace on the next line otherwise
+                    # it will not work due to a regex bug in meta-swupdate
+                    $coreos_swupdate_extends(files) 
                 );
                 bootenv: (
                         {
@@ -96,6 +111,9 @@ software =
                             value = "C:BOOT1:KERNEL.EFI";
 
                         }
+                        # Don't remove the trailing whitspace on the next line otherwise
+                        # it will not work due to a regex bug in meta-swupdate
+                        $coreos_swupdate_extends(bootenv) 
                 );
             }
         }