[ImageBuilder][PATCH] Fix Xen boot-time cpupools handling

[Michal Orzel <michal.orzel@xxxxxxx>]

When retrieving a phandle for a CPU node using "fdtget -t x", the
resulting hex number (in case the phandle exists) lacks the '0x' prefix.
This value is subsequently used to construct the cpupool-cpus property.
This results in an incorrect property generation that leads to Xen
failure (example: cpupool-cpus < a> instead of < 0xa>). Address the
issue by adding 0x prefix to the result from fdtget.

Additionally, avoid unnecessary regeneration of the phandle if it already
exists.

Fixes: b687773b5046 ("Add support for Xen boot-time cpupools")
Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
---
This only worked if phandle did not exist or if its value did not contain a-f
and was regenerated anyway.
---
 scripts/uboot-script-gen | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
index 078a667c61ab..3cc6b47c7c62 100755
--- a/scripts/uboot-script-gen
+++ b/scripts/uboot-script-gen
@@ -262,12 +262,12 @@ function add_device_tree_cpupools()
             fi
 
             # set phandle for a cpu if there is none
-            if ! phandle=$(fdtget -t x "${DEVICE_TREE}" "$cpu" "phandle" 2> 
/dev/null)
+            if ! phandle="0x$(fdtget -t x "${DEVICE_TREE}" "$cpu" "phandle" 2> 
/dev/null)"
             then
                 get_next_phandle phandle
+                dt_set "$cpu" "phandle" "hex" "$phandle"
             fi
 
-            dt_set "$cpu" "phandle" "hex" "$phandle"
             cpu_phandles="$cpu_phandles $phandle"
             cpu_list="$cpu_list $cpu"
         done
-- 
2.25.1