Re: [RFC PATCH v3 02/19] scripts: bug fixes in update-aarch64-cpu-sysreg-properties

> On 20 Jul 2026, at 7:54 PM, Eric Auger <[email protected]> wrote:
> 
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> 
> On 7/16/26 11:38 PM, Khushit Shah wrote:
>> - handle quoted bitstrings  and decimal
>> - skip Values.ValueRange entries.
> The above is the issue you reported on my v6. See my comment on the
> other thread.
Acked.
>> - Emit unique RESx_{lsb} names for reserved fields so no two fields in
>>  a register share a name.
> The requirement for naming RES field needs to be explained. I understand
> that now you expose all fields including those which are not writable it
> may be required but at this stage I still fail why this is requested.
I think we don’t need to expose RES fields to users. 
I was thinking of case where a RES0 field is repurposed for
something else, but that should be taken care by zeroing the
ID regs array before initiating the named model hierarchy.
(RES1 field in CTR_EL0 needs some handling).

On why we even need to expose non-writable fields:
- Assume some non-writable field mismatches for the model and
  host, why do we want to stop users from explicitly overriding
  the model's field value to host value?

>> - Emit a dummy 64-bit VAL field for registers with no defined fields,
>>  such as AIDR_EL1 and REVIDR_EL1.
> This is yet another functional change that could be separate.
Acked, will do in v4.

> Thanks
> 
> Eric
>> 
>> Signed-off-by: Khushit Shah <[email protected]>
>> ---
>> .../update-aarch64-cpu-sysreg-properties.py   | 67 +++++++++++++------
>> 1 file changed, 45 insertions(+), 22 deletions(-)
>> mode change 100644 => 100755 scripts/update-aarch64-cpu-sysreg-properties.py
>> 
>> diff --git a/scripts/update-aarch64-cpu-sysreg-properties.py b/scripts/update-aarch64-cpu-sysreg-properties.py
>> old mode 100644
>> new mode 100755
>> index 9e829fda2e..ecc35db528
>> --- a/scripts/update-aarch64-cpu-sysreg-properties.py
>> +++ b/scripts/update-aarch64-cpu-sysreg-properties.py
>> @@ -106,6 +106,29 @@ def collect_fields(item, bit_offset=0):
>> 
>>     return fields
>> 
>> +def parse_value_int(raw_val):
>> +    if raw_val is None or isinstance(raw_val, bool):
>> +        return None
>> +
>> +    # may already be real number
>> +    if isinstance(raw_val, int):
>> +        return raw_val
>> +
>> +    raw_str = str(raw_val).strip()
>> +
>> +    if "'" in raw_str:
>> +        # quoted bitstring like "'0100'"
>> +        bits = raw_str.replace("'", "")
>> +        try:
>> +            return int(bits, 2)
>> +        except ValueError:
>> +            return None
>> +
>> +    # unquoted, try decimal
>> +    try:
>> +        return int(raw_str, 0)
>> +    except ValueError:
>> +        return None
>> 
>> def extract_field_enums(field):
>>     enums = []
>> @@ -124,32 +147,23 @@ def extract_field_enums(field):
>>     if not isinstance(val_entries, list):
>>         return enums
>> 
>> +    # A Values.ValueRange field specifies start and end value for a range.
>> +    # Don't enumerate anything for them.
>> +    for val_entry in val_entries:
>> +        if isinstance(val_entry, dict) and \
>> +           val_entry.get("_type") == "Values.ValueRange":
>> +               return []
>> +
>>     for val_entry in val_entries:
>>         if not isinstance(val_entry, dict):
>>             continue
>> -            
>> +
>>         if val_entry.get("_type") == "Values.Value":
>> -            raw_val = val_entry.get("value")
>> -            if raw_val is None:
>> +            int_val = parse_value_int(val_entry.get("value"))
>> +            if int_val is None:
>>                 continue
>> -                
>> -            # some of the values have ' like "'0100'"
>> -            raw_val_str = str(raw_val).strip().replace("'", "")
>> -            
>> -            try:
>> -                # convert into bin 
>> -                int_val = int(raw_val_str, 2)
>> -            except ValueError:
>> -                try:
>> -                    # Fallback to dec if not bin
>> -                    int_val = int(raw_val_str, 0)
>> -                except ValueError:
>> -                    continue
>> -            
>> -            enums.append({
>> -                'value': int_val
>> -            })
>> -            
>> +            enums.append({'value': int_val})
>> +
>>     return enums
>> 
>> def generate_sysreg_properties_from_registers_json(id_reg_names, raw_json_path):
>> @@ -210,7 +224,7 @@ def generate_sysreg_properties_from_registers_json(id_reg_names, raw_json_path):
>>                        msb > current_fieldset_fields[unique_key]['msb']:
>>                         enums = extract_field_enums(val)
>>                         current_fieldset_fields[unique_key] = {
>> -                            'raw_name': name,
>> +                            'raw_name': unique_key,
>>                             'lsb': lsb,
>>                             'msb': msb,
>>                             'width': width,
>> @@ -238,6 +252,15 @@ def generate_sysreg_properties_from_registers_json(id_reg_names, raw_json_path):
>>         # Sort decreasing lsbs
>>         sorted_fields = sorted(unique_fields.items(),
>>                                key=lambda x: x[1]['lsb'], reverse=True)
>> +        if len(sorted_fields) == 0:
>> +            # cases like REVIDR_EL1 and AIDR_EL1.
>> +            # augment a dummy fields VAL.
>> +            sorted_fields.append(('VAL', {
>> +                'lsb': 0,
>> +                'msb': 63,
>> +                'width': 64,
>> +                'enums': []
>> +            }))
>> 
>>         for unique_key, bits in sorted_fields:
>>             enums_list = bits.get('enums', [])
>