Support ODROID C4 SBC (#926)

* initial ODROID-C4 support
* setting clk_ignore_unused

buildroot-external/board/hardkernel/odroid-c4/uboot-boot.ush

@@ -0,0 +1,83 @@
+
+###########################################
+
+part start mmc ${devnum} 9 mmc_env
+mmc dev ${devnum}
+setenv loadbootstate " \
+    echo 'loading env...'; \
+    mmc read ${ramdisk_addr_r} ${mmc_env} 0x10; \
+    env import -c ${ramdisk_addr_r} 0x2000;"
+
+setenv storebootstate " \
+    echo 'storing env...'; \
+    env export -c -s 0x2000 ${ramdisk_addr_r} BOOT_ORDER BOOT_A_LEFT BOOT_B_LEFT MACHINE_ID; \
+    mmc write ${ramdisk_addr_r} ${mmc_env} 0x10;"
+
+run loadbootstate
+test -n "${BOOT_ORDER}" || setenv BOOT_ORDER "A B"
+test -n "${BOOT_A_LEFT}" || setenv BOOT_A_LEFT 3
+test -n "${BOOT_B_LEFT}" || setenv BOOT_B_LEFT 3
+
+# HassOS bootargs
+setenv bootargs_hassos "zram.enabled=1 zram.num_devices=3 apparmor=1 security=apparmor systemd.machine_id=${MACHINE_ID} cgroup_enable=memory clk_ignore_unused usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u"
+
+# HassOS system A/B
+setenv bootargs_a "root=PARTUUID=48617373-06 rootfstype=squashfs ro rootwait"
+setenv bootargs_b "root=PARTUUID=48617373-08 rootfstype=squashfs ro rootwait"
+
+usb start
+
+# Load extraargs
+fileenv mmc ${devnum}:1 ${ramdisk_addr_r} cmdline.txt cmdline
+fatload mmc ${devnum}:1 ${fdt_addr_r} meson-sm1-odroid-c4.dtb
+
+# logical volumes get numbered after physical ones.
+# 1. boot
+# 2. Extended partition
+# 3. Overlay
+# 4. Data
+# 5. KernelA
+# 6. SystemA
+# 7. KernelB
+# 8. SystemB
+# 9. BootInfo
+setenv bootargs
+for BOOT_SLOT in "${BOOT_ORDER}"; do
+  if test "x${bootargs}" != "x"; then
+    # skip remaining slots
+  elif test "x${BOOT_SLOT}" = "xA"; then
+    if test ${BOOT_A_LEFT} -gt 0; then
+      setexpr BOOT_A_LEFT ${BOOT_A_LEFT} - 1
+      echo "Found valid slot A, ${BOOT_A_LEFT} attempts remaining"
+      setenv load_kernel "ext4load mmc ${devnum}:5 ${kernel_addr_r} Image"
+      setenv bootargs "${bootargs_hassos} ${bootargs_a} rauc.slot=A ${cmdline}"
+    fi
+  elif test "x${BOOT_SLOT}" = "xB"; then
+    if test ${BOOT_B_LEFT} -gt 0; then
+      setexpr BOOT_B_LEFT ${BOOT_B_LEFT} - 1
+      echo "Found valid slot B, ${BOOT_B_LEFT} attempts remaining"
+      setenv load_kernel "ext4load mmc ${devnum}:7 ${kernel_addr_r} Image"
+      setenv bootargs "${bootargs_hassos} ${bootargs_b} rauc.slot=B ${cmdline}"
+    fi
+  fi
+done
+
+if test -n "${bootargs}"; then
+  run storebootstate
+else
+  echo "No valid slot found, resetting tries to 3"
+  setenv BOOT_A_LEFT 3
+  setenv BOOT_B_LEFT 3
+  run storebootstate
+  reset
+fi
+
+echo "Loading kernel"
+run load_kernel
+echo " Starting kernel"
+printenv load_kernel
+printenv bootargs
+booti ${kernel_addr_r} - ${fdt_addr_r}
+
+echo "Fails on boot"
+reset