ostree-initrd: Make it an initramfs, not initrd

The reasoning here is to allow initramfs generated by this recipe
to be included in FIT.

To do so w/o changing openembedded-core (it allows only cpio format) -
init script should be able to execute from a rootfs (i.e. true initramfs),
not ramdisk (initrd).
See [1] for more information on these keywords.

The gist of this change is switch from `pivot_root` to `switch_root`.
This also allows to get rid of some clutter, since `switch_root` handles
transition to new sysroot all by itself.
Again, see [1] for details on these utility/syscall.

[1] https://www.kernel.org/doc/Documentation/filesystems/ramfs-rootfs-initramfs.txt

Signed-off-by: Yevgeny Popovych <yevgenyp@pointgrab.com>

3 files changed, 3 insertions, 2 deletions

diff --git a/classes/sota.bbclass b/classes/sota.bbclass
index 0eb8981..f5c6247 100644
--- a/classes/sota.bbclass
+++ b/classes/sota.bbclass
@@ -23,7 +23,7 @@ WKS_FILE_sota ?= "sdimage-sota.wks"
 
 EXTRA_IMAGEDEPENDS_append_sota = " parted-native mtools-native dosfstools-native"
 
-INITRAMFS_FSTYPES ??= "${@oe.utils.ifelse(d.getVar('OSTREE_BOOTLOADER', True) == 'u-boot', 'ext4.gz.u-boot', 'ext4.gz')}"
+INITRAMFS_FSTYPES ??= "${@oe.utils.ifelse(d.getVar('OSTREE_BOOTLOADER', True) == 'u-boot', 'cpio.gz.u-boot', 'cpio.gz')}"
 
 # Please redefine OSTREE_REPO in order to have a persistent OSTree repo
 OSTREE_REPO ?= "${DEPLOY_DIR_IMAGE}/ostree_repo"
diff --git a/classes/sota_qemux86-64.bbclass b/classes/sota_qemux86-64.bbclass
index 9ef531d..0850af6 100644
--- a/classes/sota_qemux86-64.bbclass
+++ b/classes/sota_qemux86-64.bbclass
@@ -4,7 +4,7 @@ IMAGE_FSTYPES_remove = "wic"
 PREFERRED_PROVIDER_virtual/bootloader_sota = "u-boot"
 UBOOT_MACHINE_sota = "qemu-x86_defconfig"
 OSTREE_BOOTLOADER ?= "u-boot"
-INITRAMFS_FSTYPES ?= "ext4.gz"
+INITRAMFS_FSTYPES ?= "cpio.gz"
 
 OSTREE_KERNEL_ARGS ?= "ramdisk_size=16384 rw rootfstype=ext4 rootwait rootdelay=2 ostree_root=/dev/hda"
 
diff --git a/classes/sota_raspberrypi.bbclass b/classes/sota_raspberrypi.bbclass
index e69ccf8..e5f002d 100644
--- a/classes/sota_raspberrypi.bbclass
+++ b/classes/sota_raspberrypi.bbclass
@@ -3,6 +3,7 @@ RPI_USE_U_BOOT_sota = "1"
 KERNEL_CLASSES_append_sota = " kernel-fitimage"
 KERNEL_IMAGETYPE_sota = "fitImage"
 OSTREE_KERNEL = "${KERNEL_IMAGETYPE}-${INITRAMFS_IMAGE}-${MACHINE}.bin"
+INITRAMFS_FSTYPES = "cpio.gz"
 
 PREFERRED_PROVIDER_virtual/bootloader_sota ?= "u-boot"
 UBOOT_ENTRYPOINT_sota ?= "0x00008000"