[ImageBuilder v2] Make DEVICE_TREE optional parameter

[Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>]

There are systems where device tree binary is passed by the U-Boot as
$fdtcontroladdr. In such cases, no external device tree binary is provided
during uboot script generation.

This is an enhancement on top of the following commit:-
uboot-script-gen: Dynamically compute addr and size when loading bina…

When DEVICE_TREE is not present, user should provide '-s' as the addresses and
sizes should be computed dynamically from U-Boot.

Also, fixed uboot-script-gen to set host_kernel_addr when BOOT_CMD="none" and
'-s' is not used.

Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
---
This patch should be applied after the previous patch.
"[ImageBuilder v2] Add config option to use separate load commands for..."

Changes from :-

v1 :- 1. Check that user provides '-s' when DEVICE_TREE is not set, instead of
setting CALC silently.

2. Set 'host_fdt_addr' to '\${fdtcontroladdr}' when DEVICE_TREE is not set.

3. Add a fix for BOOT_CMD="none".
 
 README.md                |  5 ++++-
 scripts/uboot-script-gen | 29 +++++++++++++++++++++++------
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 59919df..fc448e0 100644
--- a/README.md
+++ b/README.md
@@ -92,7 +92,10 @@ Where:
   DTB are stored in 'host_kernel_addr' and 'host_fdt_addr' u-boot
   env variables respectively, to be used manually when booting.
 
-- DEVICE_TREE specifies the DTB file to load.
+- DEVICE_TREE specifies the DTB file to load. If not set, then $fdtcontroladdr
+  is used as the address of the DTB loaded by u-boot. If user does not set this
+  option, then '-s' should be provided to ensure that addresses and sizes are
+  calculated dynamically by uboot.
 
 - XEN specifies the Xen hypervisor binary to load. Note that it has to
   be a regular Xen binary, not a u-boot binary.
diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
index 656de72..be61fc4 100755
--- a/scripts/uboot-script-gen
+++ b/scripts/uboot-script-gen
@@ -591,7 +591,7 @@ function device_tree_editing()
 
 function fill_reserved_spaces_from_dtb()
 {
-    if [ ! -f $DEVICE_TREE ]
+    if test ! -f $DEVICE_TREE || test -z "$DEVICE_TREE"
     then
         if test "$CALC"; then
             return
@@ -1674,6 +1674,16 @@ fi
 
 rm -f $UBOOT_SOURCE $UBOOT_SCRIPT
 
+if test -z "$DEVICE_TREE"
+then
+    if test -z "$CALC"
+    then
+       echo "DEVICE_TREE is unset and -s is not specified"
+       exit 1
+    fi
+    echo "setenv host_fdt_addr \${fdtcontroladdr}" >> $UBOOT_SOURCE
+fi
+
 if test "$FIT"
 then
     echo 'fit_addr=$fileaddr' >>  $UBOOT_SOURCE
@@ -1721,9 +1731,13 @@ then
     done
 fi
 
-check_file_type $DEVICE_TREE "Device Tree Blob"
-device_tree_addr=$memaddr
-load_file $DEVICE_TREE "host_fdt" "$XEN_LOAD"
+if test "$DEVICE_TREE"
+then
+    check_file_type $DEVICE_TREE "Device Tree Blob"
+    device_tree_addr=$memaddr
+    load_file $DEVICE_TREE "host_fdt" "$XEN_LOAD"
+fi
+
 bitstream_load_and_config  # bitstream is loaded last but used first
 device_tree_editing $device_tree_addr
 
@@ -1751,8 +1765,11 @@ then
     fi
 else
     # skip boot command but store load addresses to be used later
-    echo "setenv host_kernel_addr $kernel_addr" >> $UBOOT_SOURCE
-    echo "setenv host_fdt_addr $device_tree_addr" >> $UBOOT_SOURCE
+    if test -z "$CALC"
+    then
+        echo "setenv host_kernel_addr $kernel_addr" >> $UBOOT_SOURCE
+        echo "setenv host_fdt_addr $device_tree_addr" >> $UBOOT_SOURCE
+    fi
 fi
 
 if test "$FIT"
-- 
2.25.1