bootimg.bbclass: make default KERNEL_IMAGETYPE match kernel.bbclass

kernel.bbclass uses a default KERNEL_IMAGETYPE of zImage and that's also the default mentioned in documentation.conf. Update the bootimg.bbclass default value from bzImage -> zImage to be consistent.

---
 meta/classes/bootimg.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index ec9d0b7..6728e0e 100644
@@ -47,7 +47,7 @@ EFI = "${@bb.utils.contains("MACHINE_FEATURES", "efi", "1", "0", d)}"
 EFI_PROVIDER ?= "grub-efi"
 EFI_CLASS = "${@bb.utils.contains("MACHINE_FEATURES", "efi", "${EFI_PROVIDER}", "", d)}"
 
-KERNEL_IMAGETYPE ??= "bzImage"
+KERNEL_IMAGETYPE ??= "zImage"
 
 # Include legacy boot if MACHINE_FEATURES includes "pcbios" or if it does not
 # contain "efi". This way legacy is supported by default if neither is

1.9.1

I'm not sure. I guess most people set their preferred image type via machine config and for those that don't, switching the default is just going to cause confusion rather than being helpful.

I did wonder about moving the default definition from kernel.bbclass into bitbake.conf though. Then the duplicate default definition in bootimg.bbclass could be removed.