layerscape: ls1012afrdm: introduce dynamic partitioning

Combine fixed sizes of "kernel" and "rootfs" partitions into one
partition managed by OpenWrt splitter, it will allow better management
of chip capacity and less maintenance burden when compiled kernel image
will outgrow allocated size for kernel partition. This also changes kernel
image format, since splitter only manages kernel and rootfs partitions,
the dtb needs to be updated with the kernel, so for convenience, kernel is
packed to FIT image.

Signed-off-by: Tomasz Maciej Nowak <tomek_n@o2.pl>

package/boot/uboot-layerscape/files/ls1012afrdm-uEnv.txt

@@ -2,7 +2,7 @@ fdtaddr=0x8f000000
 loadaddr=0x81000000
 fdt_high=0xffffffffffffffff
 initrd_high=0xffffffffffffffff
-qspi_boot=sf probe 0:0;sf read $fdtaddr f00000 100000;sf read $loadaddr 1000000 1000000;bootm $loadaddr - $fdtaddr
+qspi_boot=sf probe 0:0;sf read $loadaddr 1000000 2800000;bootm $loadaddr
-bootargs=rootfstype=squashfs,jffs2 noinitrd earlycon=uart8250,mmio,0x21c0500 console=ttyS0,115200 mtdparts=1550000.quadspi:1m(bl2),4m(fip),1m(u-boot-env),4m(reserved-1),3m(pfe),2m(reserved-2),1m(dtb),16m(kernel),32m(rootfs)
+bootargs=rootfstype=squashfs,jffs2 noinitrd earlycon=uart8250,mmio,0x21c0500 console=ttyS0,115200 mtdparts=1550000.quadspi:1m(bl2),4m(fip),1m(u-boot-env),4m(reserved-1),3m(pfe),2m(reserved-2),1m(dtb),-(firmware)
 bootcmd=echo starting OpenWrt ...;pfe stop;run qspi_boot
 bootdelay=3

target/linux/layerscape/armv8_64b/config-4.14

@@ -630,6 +630,8 @@ CONFIG_MTD_NAND_FSL_IFC=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
+CONFIG_MTD_SPLIT_FIRMWARE=y
+CONFIG_MTD_SPLIT_FIT_FW=y
 CONFIG_MTD_SST25L=y
 CONFIG_MTD_UBI=y
 CONFIG_MTD_UBI_BEB_LIMIT=20

target/linux/layerscape/image/armv8_64b.mk

@@ -32,8 +32,9 @@ define Device/ls1012afrdm
     ls-append $(1)-uboot-env.bin | pad-to 10M | \
     ls-append pfe.itb | pad-to 15M | \
     ls-append-dtb $$(DEVICE_DTS) | pad-to 16M | \
-    append-kernel | pad-to 32M | \
+    append-kernel | pad-to $$(BLOCKSIZE) | \
     append-rootfs | pad-rootfs | check-size 67108865
+  KERNEL := kernel-bin | gzip | fit gzip $$(DTS_DIR)/$$(DEVICE_DTS).dtb
   KERNEL_INITRAMFS := kernel-bin | fit none $$(DTS_DIR)/$$(DEVICE_DTS).dtb
 endef
 TARGET_DEVICES += ls1012afrdm