xref: /aosp_15_r20/external/pigweed/pw_stm32cube_build/py/pw_stm32cube_build/inject_init.py (revision 61c4878ac05f98d0ceed94b57d316916de578985)
1# Copyright 2021 The Pigweed Authors
2#
3# Licensed under the Apache License, Version 2.0 (the "License"); you may not
4# use this file except in compliance with the License. You may obtain a copy of
5# the License at
6#
7#     https://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12# License for the specific language governing permissions and limitations under
13# the License.
14"""Injects pre main init to ST startup scripts."""
15
16
17import pathlib
18import re
19
20
21def add_pre_main_init(startup: str) -> str:
22    """Add pw_stm32cube_Init call to startup file
23
24    The stm32cube startup files directly call main(), while pigweed expects to
25    do some setup before main is called. This could include sys_io or system
26    clock initialization.
27
28    This adds a call to `pw_stm32cube_Init()` immediately before the call to
29    `main()`
30
31    Args:
32        startup: The startup script read into a string
33
34    Returns:
35        A new startup script with the `pw_stm32cube_Init()` call added.
36
37    Raises:
38        ValueError if the `main()` call is not found in `startup`
39    """
40    match = re.search(r'\s*bl\s+main', startup)
41    if match is None:
42        raise ValueError("`bl main` not found in startup script")
43
44    return (
45        startup[: match.start()]
46        + '\nbl pw_stm32cube_Init'
47        + startup[match.start() :]
48    )
49
50
51def inject_init(startup_in: pathlib.Path, startup_out: pathlib.Path | None):
52    """Injects pw_stm32cube_Init before main in given ST startup script.
53
54    Args:
55        startup_in: path to startup_*.s file
56        startup_out: path to write generated startup file or None.
57                    If None, output startup script printed to stdout
58    """
59    with open(startup_in, 'rb') as startup_in_file:
60        startup_in_str = startup_in_file.read().decode('utf-8', errors='ignore')
61
62    startup_out_str = add_pre_main_init(startup_in_str)
63
64    if startup_out:
65        with open(startup_out, 'w') as startup_out_file:
66            startup_out_file.write(startup_out_str)
67    else:
68        print(startup_out_str)
69