scripts: add tool to convert elf to asw for GR716

JIRA: RTOS-406

scripts/gr716-convert.py

@@ -0,0 +1,140 @@
+#!/usr/bin/env python3
+#
+# Script to convert ELF file to ASW format for GR716
+#
+# Copyright 2023 Phoenix Systems
+# Author: Lukasz Leczkowski
+#
+
+import argparse
+import os
+
+
+READELF = "sparc-phoenix-readelf"
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description="Convert ELF file to ASW format for GR716"
+    )
+    parser.add_argument("filename", help="ELF file to convert")
+    parser.add_argument("-o", "--output", help="output file")
+    parser.add_argument("-e", "--entrypoint", help="entry point address (hex)")
+    return parser.parse_args()
+
+
+def validate_file(filename: str):
+    if not os.path.isfile(filename):
+        print(f'Error: file "{filename}" not found')
+        exit(1)
+
+
+def read_phdrs(filename: str):
+    # Get offset and size of LOAD program headers
+    phdrs = os.popen(f"{READELF} -l {filename} | grep LOAD").read()
+
+    # PLO has only one LOAD program header
+    # Get offset and size of LOAD program headers
+    phdrs = phdrs.split()
+    phdrs.remove("LOAD")
+
+    offset = int(phdrs[0], 16)
+    filesize = int(phdrs[3], 16)
+
+    return offset, filesize
+
+
+def crc_encode(data: bytearray):
+    """16-bit CRC according to ECSS-E-70-41A"""
+
+    def crc(byte: int, chk: int):
+        for i in range(8):
+            if (byte & 0x80) ^ ((chk & 0x8000) >> 8):
+                chk = ((chk << 1) ^ 0x1021) & 0xFFFF
+            else:
+                chk = (chk << 1) & 0xFFFF
+            byte = byte << 1
+        return chk
+
+    chk = 0xFFFF
+    for val in data:
+        chk = crc(val, chk)
+
+    return chk
+
+
+def convert_file(inputfn: str, outputfn: str, entry: int):
+    offset, filesize = read_phdrs(inputfn)
+
+    with open(args.filename, "rb") as inputfile, open(outputfn, "w+b") as outputfile:
+        inputfile.seek(offset)
+        data = inputfile.read(filesize)
+
+        # Define image header:
+        #   user defined id
+        #   entry point
+        #   image section headers
+        #   image header checksum
+
+        usr_id = 0xDEADBEEF
+
+        outputfile.write(usr_id.to_bytes(4, "big"))
+        outputfile.write(entry.to_bytes(4, "big"))
+
+        # entry point magic - undocumented errata - instead of section 0
+        magic = (
+            (0x0).to_bytes(4, "big")
+            + "EP->".encode("ascii")
+            + entry.to_bytes(4, "big")
+            + " GR716 \0".encode("ascii")
+        )
+        outputfile.write(magic)
+
+        # Define image section header:
+        #   flags: 0x1 - copy to RAM
+        #   relative offset to data: 0x2B (in 32-bit words)
+        #   absolute destination address: entry point
+        #   length of image (in 32-bit words)
+        #   checksum of image data
+
+        outputfile.write((0x1).to_bytes(4, "big"))
+        outputfile.write((0x2B).to_bytes(4, "big"))
+        outputfile.write(entry.to_bytes(4, "big"))
+        outputfile.write((filesize // 4).to_bytes(4, "big"))
+
+        data_chk = crc_encode(bytearray(data))
+        outputfile.write(data_chk.to_bytes(2, "big"))
+        outputfile.write(b"\x00\x00")
+
+        # write 6 clear sections (unused)
+        for i in range(6):
+            for j in range(5):
+                outputfile.write((0x0).to_bytes(4, "big"))
+
+        outputfile.write(b"\x00\x00")  # padding
+
+        hdr_chk_pos = outputfile.tell()
+        outputfile.seek(0, 0)
+
+        # calculate checksum over image section header
+        hdrs = bytearray(outputfile.read())
+        hdr_chk = crc_encode(hdrs)
+        outputfile.seek(hdr_chk_pos, 0)
+        outputfile.write(hdr_chk.to_bytes(2, "big"))
+
+        outputfile.write(data)
+
+    print(f"Converted {inputfn} to {outputfn}")
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    try:
+        entry = int(args.entrypoint, 16) if args.entrypoint else 0x31000000
+    except ValueError as e:
+        print(f"Error: {args.entrypoint} is not a valid entry point address")
+        exit(1)
+
+    validate_file(args.filename)
+    outputfn = args.output if args.output else args.filename.replace(".elf", ".asw")
+    convert_file(args.filename, outputfn, entry)