[RESEND, RFC 1/8] tools: config: yaml: Add board config class to generate config binaries

[Alper Nebi Yasak]

On 06/04/2022 15:29, Neha Malcom Francis wrote:
> For validating config files and generating binary config artifacts, here
> board specific config class is added.
> 
> Add function cfgBinaryGen() in tibcfg_gen.py. It uses TIBoardConfig
> class to load given schema and config files in YAML, validate them and
> generate binaries.

The subject lines (of other patches as well) sound too generic when most
of them are TI specific, I'd expect at least a 'ti:' tag except where
you already include more specific terms like a board name.

(This one could be "tools: ti: Add ..." for example).

> 
> Signed-off-by: Tarun Sahu <t-sahu at ti.com>
> [n-francis at ti.com: prepared patch for upstreaming]
> Signed-off-by: Neha Malcom Francis <n-francis at ti.com>
> ---
>  test/py/requirements.txt |   1 +
>  tools/tibcfg_gen.py      | 116 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 117 insertions(+)
>  create mode 100644 tools/tibcfg_gen.py
> 
> diff --git a/test/py/requirements.txt b/test/py/requirements.txt
> index 33c5c0bbc4..a91ba64563 100644
> --- a/test/py/requirements.txt
> +++ b/test/py/requirements.txt
> @@ -4,6 +4,7 @@ coverage==4.5.4
>  extras==1.0.0
>  fixtures==3.0.0
>  importlib-metadata==0.23
> +jsonschema==4.0.0
>  linecache2==1.0.0
>  more-itertools==7.2.0
>  packaging==19.2
> diff --git a/tools/tibcfg_gen.py b/tools/tibcfg_gen.py
> new file mode 100644
> index 0000000000..7635596906
> --- /dev/null
> +++ b/tools/tibcfg_gen.py
> @@ -0,0 +1,116 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +# Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com/
> +#
> +# TI Board Configuration Class for Schema Validation and Binary Generation
> +#
> +
> +from jsonschema import validate
> +
> +import yaml
> +import os
> +import sys

Standard library imports should appear before third-party libraries,
with an empty line between them.

> +
> +
> +class TIBoardConfig:
> +    file_yaml = {}
> +    schema_yaml = {}
> +    data_rules = {}

These belong in __init__ as they are per-instance attributes.

> +
> +    def __init__(self):
> +        pass
> +
> +    def Load(self, file, schema, data_rules=""):

You can rename this to be the __init__ function.

> +        with open(file, 'r') as f:
> +            self.file_yaml = yaml.safe_load(f)
> +        with open(schema, 'r') as sch:
> +            self.schema_yaml = yaml.safe_load(sch)
> +        self.data_rules = data_rules
> +
> +    def CheckValidity(self):
> +        try:
> +            validate(self.file_yaml, self.schema_yaml)
> +            return True
> +        except Exception as e:
> +            print(e)
> +            return False

You can also do this validation immediately after loading the yaml files
in the __init__(), and then safely assume any created object is valid.

> +
> +    def __ConvertToByteChunk(self, val, data_type):

Methods should be in snake_case. Also consider using a single underscore
as the prefix, double underscore does some special name mangling.

> +        br = []
> +        size = 0
> +        if(data_type == "#/definitions/u8"):
> +            size = 1
> +        elif(data_type == "#/definitions/u16"):
> +            size = 2
> +        elif(data_type == "#/definitions/u32"):
> +            size = 4
> +        else:
> +            return -1

I think this case should raise an error of some kind.

> +        if(type(val) == int):
> +            while(val != 0):

In general, don't use parentheses with if, while etc.

> +                br = br + [(val & 0xFF)]
> +                val = val >> 8
> +        while(len(br) < size):
> +            br = br + [0]
> +        return br

This all looks like val.to_bytes(size, 'little'), but as a list instead
of bytes. If you want to get fancy, have a look at the struct module.
(For example, struct.pack('<L', val) )

> +
> +    def __CompileYaml(self, schema_yaml, file_yaml):
> +        br = []

Consider using a bytearray instead of a list-of-ints here.

> +        for key in file_yaml.keys():

I think things would be more readable if you extracted

    node = file_yaml[key]
    node_schema = schema_yaml['properties'][key]
    node_type = node_schema.get('type')

as variables here and used those in the following code.

> +            if not 'type' in schema_yaml['properties'][key]:
> +                br = br + \

br += ... would be nicer for all of these.

> +                    self.__ConvertToByteChunk(
> +                        file_yaml[key], schema_yaml['properties'][key]["$ref"])
> +            elif schema_yaml['properties'][key]['type'] == 'object':
> +                br = br + \
> +                    self.__CompileYaml(
> +                        schema_yaml['properties'][key], file_yaml[key])
> +            elif schema_yaml['properties'][key]['type'] == 'array':
> +                for item in file_yaml[key]:
> +                    if not isinstance(item, dict):
> +                        br = br + \
> +                            self.__ConvertToByteChunk(
> +                                item, schema_yaml['properties'][key]['items']["$ref"])
> +                    else:
> +                        br = br + \
> +                            self.__CompileYaml(
> +                                schema_yaml['properties'][key]['items'], item)
> +        return br
> +
> +    def GenerateBinaries(self, out_path=""):
> +        if not os.path.isdir(out_path):
> +            os.mkdir(out_path)
> +        if(self.CheckValidity()):
> +            for key in self.file_yaml.keys():
> +                br = []

You don't need this assignment, it's overwritten in the next one anyway.

> +                br = self.__CompileYaml(
> +                    self.schema_yaml['properties'][key], self.file_yaml[key])
> +                with open(out_path + "/" + key + ".bin", 'wb') as cfg:

Construct file paths with os.path.join() here and below.

> +                    cfg.write(bytearray(br))
> +        else:
> +            raise ValueError("Config YAML Validation failed!")
> +
> +    def DeleteBinaries(self, out_path=""):
> +        if os.path.isdir(out_path):
> +            for key in self.file_yaml.keys():
> +                if os.path.isfile(out_path + "/" + key + ".bin"):
> +                    os.remove(out_path + "/" + key + ".bin")
> +
> +
> +def cfgBinaryGen():
> +    """Generate config binaries from YAML config file and YAML schema
> +        Arguments:
> +            - config_yaml: board config file in YAML
> +            - schema_yaml: schema file in YAML to validate config_yaml against
> +    Pass the arguments along with the filename in the Makefile.
> +    """
> +    tibcfg = TIBoardConfig()
> +    config_yaml = sys.argv[1]
> +    schema_yaml = sys.argv[2]
> +    try:
> +        tibcfg.Load(config_yaml, schema_yaml)
> +    except:
> +        raise ValueError("Could not find config files!")
> +    tibcfg.GenerateBinaries(os.environ['O'])

I think it'd be better to pass the directory as an -o / --output-dir
argument instead of reading it from environment. You can use argparse to
parse the command line arguments.

> +
> +
> +cfgBinaryGen()

This should be guarded by if __name__ == '__main__'.