[util] fix bug in flash scrambling script

The address used to compute the XEX scrambling mask was incorrect, as
the VMEM file contains multiple flash word addresses in a line.

Signed-off-by: Timothy Trippel <[email protected]>

util/design/gen-flash-img.py

@@ -11,7 +11,6 @@
 """
 
 import argparse
-import functools
 import re
 import sys
 from dataclasses import dataclass
@@ -107,7 +106,6 @@ class FlashScramblingConfigs:
  data_key: int = None
 
 
-@functools.lru_cache(maxsize=None)
 def _xex_scramble(data: int, word_addr: int, flash_addr_key: int,
  flash_data_key: int) -> int:
  operand_a = ((flash_addr_key & FLASH_GF_OPERAND_A_MASK) >>
@@ -246,12 +244,14 @@ def _reformat_flash_vmem(
  line_items = line.split()
  reformatted_line = ""
  address = None
+ address_offset = 0
  data = None
  for item in line_items:
  # Process the address first.
  if re.match(r"^@", item):
  reformatted_line += item
  address = int(item.lstrip("@"), 16)
+ address_offset = 0
  # Process the data words.
  else:
  data = int(item, 16)
@@ -262,7 +262,7 @@ def _reformat_flash_vmem(
  data_w_intg_ecc &= 0xF_FFFF_FFFF_FFFF_FFFF
  if scrambling_configs.scrambling_enabled:
  intg_ecc = data_w_intg_ecc & (0xF << FLASH_WORD_SIZE)
- data = _xex_scramble(data, address,
+ data = _xex_scramble(data, address + address_offset,
  scrambling_configs.addr_key,
  scrambling_configs.data_key)
  data_w_intg_ecc = intg_ecc | data
@@ -274,6 +274,7 @@ def _reformat_flash_vmem(
  data_w_intg_ecc)
  reformatted_line += str.format(VMEM_FORMAT_STR,
  data_w_full_ecc)
+ address_offset += 1
 
  # Append reformatted line to what will be the new output VMEM file.
  reformatted_vmem_lines.append(reformatted_line)