userspace: app_shared_mem: Fixed incorrect implementation.

This feature was failing on a default ARM core MPU. The linker
script that was getting created was not able to align the required
partitions at prebuilt time.

The old implementation relied on the prebuilt to finish then
extract the size information which was then used to align the regions.
This fails because the size of the alignment and the fill in the
linker needs to be available at prebuilt time else it cant manage
the final elf file generation. We cant have 2 different sizes of
prebuilt and final elf file.

This implementation will get the alignment requirements met at
prebuilt time.

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
diff --git a/scripts/gen_app_partitions.py b/scripts/gen_app_partitions.py
new file mode 100644
index 0000000..6bac8c0
--- /dev/null
+++ b/scripts/gen_app_partitions.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+import sys
+import argparse
+import os
+import re
+import string
+from elf_helper import ElfHelper
+from elftools.elf.elffile import ELFFile
+
+
+# This script will create linker comands for power of two aligned MPU
+# when APP_SHARED_MEM is enabled.
+print_template = """
+/* Auto generated code do not modify */
+. = ALIGN( 1 << LOG2CEIL(data_smem_{0}b_end - data_smem_{0}));
+data_smem_{0} = .;
+KEEP(*(SORT(data_smem_{0}*)))
+. = ALIGN(_app_data_align);
+data_smem_{0}b_end = .;
+. = ALIGN( 1 << LOG2CEIL(data_smem_{0}b_end - data_smem_{0}));
+"""
+
+
+def find_partitions(filename, full_list_of_partitions, partitions_source_file):
+    with open(filename, 'rb') as f:
+        full_lib = ELFFile( f)
+        if (not full_lib):
+            print("Error parsing file: ",filename)
+            os.exit(1)
+
+        sections = [ x for x in full_lib.iter_sections()]
+        for section in sections:
+            if ("smem" in  section.name and not ".rel" in section.name):
+                partition_name = section.name.split("data_smem_")[1]
+                if partition_name not in full_list_of_partitions:
+                    full_list_of_partitions.append(partition_name)
+                    if args.verbose:
+                        partitions_source_file.update({partition_name: filename})
+
+    return( full_list_of_partitions, partitions_source_file)
+
+def cleanup_remove_bss_regions(full_list_of_partitions):
+    for partition in full_list_of_partitions:
+        if (partition+"b" in full_list_of_partitions):
+            full_list_of_partitions.remove(partition+"b")
+    return full_list_of_partitions
+
+def generate_final_linker(linker_file, full_list_of_partitions):
+    string= ''
+    for partition in full_list_of_partitions:
+        string += print_template.format(partition)
+
+    with open(linker_file, "w") as fw:
+        fw.write(string)
+
+
+def parse_args():
+    global args
+    parser = argparse.ArgumentParser(
+        description=__doc__,
+        formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument("-d", "--directory", required=True,
+                        help="Root build directory")
+    parser.add_argument("-o", "--output", required=False,
+                        help="Output ld file")
+    parser.add_argument("-v", "--verbose", action="count", default =0,
+                        help="Verbose Output")
+    args = parser.parse_args()
+
+
+def main():
+    parse_args()
+    root_directory = args.directory
+    linker_file = args.output
+    full_list_of_partitions = []
+    partitions_source_file= {}
+
+    for dirpath, dirs, files in os.walk(root_directory):
+        for filename in files:
+            if re.match(".*\.obj$",filename):
+                fullname = os.path.join(dirpath, filename)
+                full_list_of_partitions, partitions_source_file = find_partitions(fullname, full_list_of_partitions, partitions_source_file)
+
+    full_list_of_partitions = cleanup_remove_bss_regions(full_list_of_partitions)
+    generate_final_linker(linker_file, full_list_of_partitions)
+    if args.verbose:
+        print("Partitions retrieved: PARTITION, FILENAME")
+        print([key + " "+ partitions_source_file[key] for key in full_list_of_partitions])
+
+if __name__ == '__main__':
+    main()