blob: 24425f1d6f75a87f252830b078753375d0daf6b0 [file] [log] [blame]
# Copyright lowRISC contributors.
# Licensed under the Apache License, Version 2.0, see LICENSE for details.
# SPDX-License-Identifier: Apache-2.0
'''A wrapper around reggen for otbn.hjson'''
import os
from typing import Optional, Tuple
from reggen import ip_block, reg_block
_LR_RETVAL = None # type: Optional[Tuple[int, object]]
def load_registers() -> Tuple[int, object]:
'''Load otbn.hjson with reggen
Returns (width, regs) where width is the register width and regs is a
list of Register, MultiRegister or Window objects. Memoized.
'''
global _LR_RETVAL
if _LR_RETVAL is not None:
return _LR_RETVAL
path = os.path.join(os.path.dirname(__file__),
'..', '..', 'data', 'otbn.hjson')
try:
obj = ip_block.IpBlock.from_path(path, [])
except ValueError as err:
raise RuntimeError('Failed to parse {!r}: {}'.format(path, err))
reg_bit_width = obj.regwidth
assert isinstance(reg_bit_width, int) and reg_bit_width >= 0
reg_byte_width = (reg_bit_width + 7) // 8
registers = obj.reg_blocks[None]
assert isinstance(registers, reg_block.RegBlock)
_LR_RETVAL = (reg_byte_width, registers)
return _LR_RETVAL