Enable pcbios wic plugin to work with custom kernels

The plugin assumed that custom kernels always have a -${KERNEL_NAME}
suffix, but there is no guarantee for that. The suffix might be
something else or might not exist at all.

Instead of searching for and replacing KERNEL_NAME the information is
fetched from KERNEL_FILE by splitting at "-".

Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>

meta/classes/wic-img.bbclass

@@ -96,7 +96,7 @@ WICVARS += "\
            BBLAYERS IMGDEPLOYDIR DEPLOY_DIR_IMAGE FAKEROOTCMD IMAGE_BASENAME IMAGE_BOOT_FILES \
            IMAGE_LINK_NAME IMAGE_ROOTFS INITRAMFS_FSTYPES INITRD INITRD_LIVE ISODIR RECIPE_SYSROOT_NATIVE \
            ROOTFS_SIZE STAGING_DATADIR STAGING_DIR STAGING_LIBDIR TARGET_SYS TRANSLATED_TARGET_ARCH \
-           KERNEL_NAME KERNEL_FILE"
+           KERNEL_FILE"
 
 # Isar specific vars used in our plugins
 WICVARS += "KERNEL_IMAGE INITRD_IMAGE DISTRO DISTRO_ARCH"

meta/scripts/lib/wic/plugins/source/bootimg-pcbios-isar.py

@@ -132,11 +132,14 @@ class BootimgPcbiosIsarPlugin(SourcePlugin):
             syslinux_conf += "LABEL boot\n"
 
             kernel_file = get_bitbake_var("KERNEL_FILE")
-            kernel_name = get_bitbake_var("KERNEL_NAME")
             rootfs_dir = get_bitbake_var("IMAGE_ROOTFS")
             kernel = os.path.basename(os.path.realpath(os.path.join(rootfs_dir, kernel_file)))
-            kernel_version = kernel[len(kernel_file)+1:-(len(kernel_name)+1)]
-            initrd = "initrd.img-%s-%s" % (kernel_version, kernel_name)
+            kernel_parts = kernel.split("-")
+            kernel_suffix = "-".join(kernel_parts[1:])
+            initrd = "initrd.img"
+
+            if kernel_suffix:
+                initrd += "-%s" % kernel_suffix
 
             syslinux_conf += "KERNEL " + kernel + "\n"
 
@@ -160,15 +163,19 @@ class BootimgPcbiosIsarPlugin(SourcePlugin):
         """
         syslinux_dir = cls._get_syslinux_dir(bootimg_dir)
 
-        staging_kernel_dir = kernel_dir
         kernel_file = get_bitbake_var("KERNEL_FILE")
-        kernel_name = get_bitbake_var("KERNEL_NAME")
         rootfs_dir = rootfs_dir['ROOTFS_DIR']
         kernel = os.path.basename(os.path.realpath(os.path.join(rootfs_dir, kernel_file)))
-        kernel_version = kernel[len(kernel_file)+1:-(len(kernel_name)+1)]
-        initrd = "initrd.img-%s-%s" % (kernel_version, kernel_name)
-        config = "config-%s-%s" % (kernel_version, kernel_name)
-        mapfile = "System.map-%s-%s" % (kernel_version, kernel_name)
+        kernel_parts = kernel.split("-")
+        kernel_suffix = "-".join(kernel_parts[1:])
+        initrd = "initrd.img"
+        config = "config"
+        mapfile = "System.map"
+
+        if kernel_suffix:
+            initrd += "-%s" % kernel_suffix
+            config += "-%s" % kernel_suffix
+            mapfile += "-%s" % kernel_suffix
 
         hdddir = "%s/hdd/boot" % cr_workdir