[bazel,otp_ctrl] OWNER_SW_CFG_ROM_ALERT_DIGEST_* values are hardcoded

[andreaskurth]

The values of OWNER_SW_CFG_ROM_ALERT_DIGEST_DEV, OWNER_SW_CFG_ROM_ALERT_DIGEST_PROD, OWNER_SW_CFG_ROM_ALERT_DIGEST_PROD_END, and OWNER_SW_CFG_ROM_ALERT_DIGEST_RMA are hardcoded in hw/ip/otp_ctrl/data/otp_ctrl_img_owner_sw_cfg.hjson. When changing the alert handler configuration and re-generating the RTL, that HJSON file does not get updated. Manually updating sw/host/opentitanlib/src/otp/alert_handler_regs.rs (see #19501) and restarting simulation does not update the HJSON either.

[andreaskurth]

CC @alphan @msfschaffner @cfrantz @jon-flatley

[dbeitel-opentitan]

@andreaskurth Just to be clear, you are saying that otp_ctrl_img_owner_sw_cfg.hjson should be automatically updated when alert_handler changes? Or the resulting image files should be updated?

[andreaskurth]

IIUC, the image files get updated when otp_ctrl_img_owner_sw_cfg.hjson changes. So I think what is missing is the automated update of otp_ctrl_img_owner_sw_cfg.hjson.

I had to do this manually multiple times, so I threw together a simple script to do the job (expects to live under util/ in the OT repo):

#!/usr/bin/env python3

import inspect
import hjson
import re
import subprocess as sp
import pathlib
import tempfile


REPO_ROOT = pathlib.Path(__file__).parent.parent.resolve()

def abspath(relpath: str):
    return str(REPO_ROOT / relpath)


# Generate temporary `alert_handler_regs.h` from `alert_handler.hjson`.
alert_handler_regs_h = tempfile.NamedTemporaryFile(prefix='alert_handler_regs',
                                                   suffix='.h')
sp.run([abspath('util/regtool.py'),
        abspath('hw/top_darjeeling/ip_autogen/alert_handler/data/alert_handler.hjson'),
        '-D',
        '-o',
        alert_handler_regs_h.name],
       check=True)

# Generate `alert_handler_regs.rs` from temporary `alert_handler_regs.h`.
alert_handler_regs_rs = abspath('sw/host/opentitanlib/src/otp/alert_handler_regs.rs')
sp.run(['bindgen',
        alert_handler_regs_h.name,
        '-o',
        alert_handler_regs_rs],
       check=True)

# Prepend license header, which `bindgen` removed, to `alert_handler_regs.rs`.
with open(alert_handler_regs_rs, 'r') as f:
    data = f.read()
with open(alert_handler_regs_rs, 'w') as f:
    header = '''// Copyright lowRISC contributors.
                // Licensed under the Apache License, Version 2.0, see LICENSE for details.
                // SPDX-License-Identifier: Apache-2.0
             '''
    header = inspect.cleandoc(header) + '\n\n'
    f.write(header + data)

# Compute new alert digest values for `otp_ctrl_img_owner_sw_cfg.hjson`.
otp_ctrl_img_owner_sw_cfg = abspath(
    'hw/ip/otp_ctrl/data/otp_ctrl_img_owner_sw_cfg.hjson')
proc = sp.run(['bazel',
               'run',
               '//sw/host/opentitantool',
               '--',
               '--rcfile=""',
               'otp',
               'alert-digest',
               otp_ctrl_img_owner_sw_cfg],
              capture_output=True, check=True)
data = hjson.loads(proc.stdout.decode())
items = data['partitions'][0]['items']
cfg = {i['name']: hex(i['value']) for i in items}

# Replace alert digest values in `otp_ctrl_img_owner_sw_cfg.hjson` while
# keeping the rest of the file intact.
with open(otp_ctrl_img_owner_sw_cfg, 'r') as f:
    raw_file = f.read()
for name, value in cfg.items():
    name_idx = raw_file.find(name)
    trailer = re.sub(r'value:\s*"?0x[a-fA-F0-9]+"?',
                     f'value: "{value}"',
                     raw_file[name_idx:],
                     count=1)
    raw_file = raw_file[:name_idx] + trailer
with open(otp_ctrl_img_owner_sw_cfg, 'w') as f:
    f.write(raw_file)

Maybe parts of this script could be used to resolve this issue