[PATCH v10 3/9] env: Allow U-Boot scripts to be placed in a .env file
Simon Glass
sjg at chromium.org
Sat Mar 12 19:14:38 CET 2022
Hi Patrick,
On Thu, 10 Feb 2022 at 04:20, Patrick DELAUNAY
<patrick.delaunay at foss.st.com> wrote:
>
> Hi Simon,
>
> On 10/22/21 05:08, Simon Glass wrote:
> > At present U-Boot environment variables, and thus scripts, are defined
> > by CONFIG_EXTRA_ENV_SETTINGS. It is painful to add large amounts of text
> > to this file and dealing with quoting and newlines is harder than it
> > should be. It would be better if we could just type the script into a
> > text file and have it included by U-Boot.
> >
> > Add a feature that brings in a .env file associated with the board
> > config, if present. To use it, create a file in a board/<vendor>
> > directory, typically called <board>.env and controlled by the
> > CONFIG_ENV_SOURCE_FILE option.
> >
> > The environment variables should be of the form "var=value". Values can
> > extend to multiple lines. See the README under 'Environment Variables:'
> > for more information and an example.
> >
> > In many cases environment variables need access to the U-Boot CONFIG
> > variables to select different options. Enable this so that the environment
> > scripts can be as useful as the ones currently in the board config files.
> > This uses the C preprocessor, means that comments can be included in the
> > environment using /* ... */
> >
> > Also support += to allow variables to be appended to. This is needed when
> > using the preprocessor.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > Reviewed-by: Marek Behún <marek.behun at nic.cz>
> > Tested-by: Marek Behún <marek.behun at nic.cz>
> > ---
> ...
> >
> >
> > MAINTAINERS | 7 +++
> > Makefile | 66 ++++++++++++++++++++++-
> > config.mk | 2 +
> > doc/usage/environment.rst | 81 ++++++++++++++++++++++++++++-
> > doc/usage/index.rst | 1 +
> > env/Kconfig | 18 +++++++
> > env/embedded.c | 1 +
> > include/env_default.h | 11 ++++
> > scripts/env2string.awk | 80 ++++++++++++++++++++++++++++
> > test/py/tests/test_env.py | 107 ++++++++++++++++++++++++++++++++++++++
> > 10 files changed, 372 insertions(+), 2 deletions(-)
> > create mode 100644 scripts/env2string.awk
> >
>
> ...
>
>
> For information, it seems the new test "test_env_text" failed when the
> gawk is not installed on Ubuntu distribution,
>
> or when /usr/bin/mawk is used as alternative (sudo update-alternatives
> --config awk)
>
> The test result is
>
> test/py/tests/test_env.py:556: in test_env_text
> check_script('''fred=123
> test/py/tests/test_env.py:542: in check_script
> assert result == expect
> E assert '#define CONF...red=123\\0"\n' == '#define CONF...nie=456\\0"\n'
> E - #define CONFIG_EXTRA_ENV_TEXT "ernie=456\0fred=123\0"
> E ? ----------
> E + #define CONFIG_EXTRA_ENV_TEXT "fred=123\0ernie=456\0"
> E ? ++++++++++
> ------------------------------------------------------------ Captured
> stdout call -------------------------------------------------------------
> +awk -f <PATH>/u-boot/scripts/env2string.awk /tmp/tmp0zgiwrd9/infile
> #define CONFIG_EXTRA_ENV_TEXT "fred=123\0"
> +awk -f <PATH>/u-boot/scripts/env2string.awk /tmp/tmpq6xej0ct/infile
> +awk -f <PATH>/u-boot/scripts/env2string.awk /tmp/tmpyrn10apn/infile
> #define CONFIG_EXTRA_ENV_TEXT "ernie=456\0fred=123\0"
>
>
> => the env variables are sorted in alphabetic order in mawk output / in
> creation order in gawk ouput
>
> I don't found solution to be POSIX compliant and to guarantee the output
> order
>
>
> >> By default, when a for loop traverses an array, the order is undefined,
>
> >> meaning that the awk implementation determines the order in which
>
> >> the array is traversed. This order is usually based on the internal
>
> >> implementation of arrays and will vary from one version of awk to
> the next.
>
>
> References:
>
> https://www.gnu.org/software/gawk/manual/html_node/Controlling-Scanning.html
>
> https://www.gnu.org/software/gawk/manual/html_node/Controlling-Array-Traversal.html
>
>
> > diff --git a/scripts/env2string.awk b/scripts/env2string.awk
> > new file mode 100644
> > index 00000000000..57d0fc8f3ba
> > --- /dev/null
> > +++ b/scripts/env2string.awk
> > @@ -0,0 +1,80 @@
> > +# SPDX-License-Identifier: GPL-2.0+
> > +#
> > +# Copyright 2021 Google, Inc
> > +#
> > +# SPDX-License-Identifier: GPL-2.0+
> > +#
> > +# Awk script to parse a text file containing an environment and convert it
> > +# to a C string which can be compiled into U-Boot.
> > +
> > +# The resulting output is:
> > +#
> > +# #define CONFIG_EXTRA_ENV_TEXT "<environment here>"
> > +#
> > +# If the input is empty, this script outputs a comment instead.
> > +
> > +BEGIN {
> > + # env holds the env variable we are currently processing
> > + env = "";
> > + ORS = ""
> > +}
> > +
>
>
> ...
>
>
> > +
> > +END {
> > + # Record the value of the variable now completed. If the variable is
> > + # empty it is not set.
> > + if (length(env) != 0) {
> > + vars[var] = env
> > + }
> > +
> > + if (length(vars) != 0) {
> > + printf("%s", "#define CONFIG_EXTRA_ENV_TEXT \"")
> > +
> > + # Print out all the variables
>
>
> ORDER is not guarantee here by awk for the loop on the "vars" array
>
>
> > + for (var in vars) {
> > + env = vars[var]
> > + print var "=" vars[var] "\\0"
> > + }
> > + print "\"\n"
> > + }
> > +}
> > diff --git a/test/py/tests/test_env.py b/test/py/tests/test_env.py
> > index 9bed2f48d77..f85cb031382 100644
> > --- a/test/py/tests/test_env.py
> > +++ b/test/py/tests/test_env.py
> > @@ -7,6 +7,7 @@
> > import os
> > import os.path
> > from subprocess import call, check_call, CalledProcessError
> > +import tempfile
> >
> > import pytest
> > import u_boot_utils
> > @@ -515,3 +516,109 @@ def test_env_ext4(state_test_env):
> > finally:
> > if fs_img:
> > call('rm -f %s' % fs_img, shell=True)
> > +
> > +def test_env_text(u_boot_console):
> > + """Test the script that converts the environment to a text file"""
> > +
> > + def check_script(intext, expect_val):
> > + """Check a test case
> > +
> > + Args:
> > + intext: Text to pass to the script
> > + expect_val: Expected value of the CONFIG_EXTRA_ENV_TEXT string, or
> > + None if we expect it not to be defined
> > + """
> > + with tempfile.TemporaryDirectory() as path:
> > + fname = os.path.join(path, 'infile')
> > + with open(fname, 'w') as inf:
> > + print(intext, file=inf)
> > + result = u_boot_utils.run_and_log(cons, ['awk', '-f', script, fname])
> > + if expect_val is not None:
> > + expect = '#define CONFIG_EXTRA_ENV_TEXT "%s"\n' % expect_val
> > + assert result == expect
> > + else:
> > + assert result == ''
> > +
> > + cons = u_boot_console
> > + script = os.path.join(cons.config.source_dir, 'scripts', 'env2string.awk')
> > +
> > + # simple script with a single var
> > + check_script('fred=123', 'fred=123\\0')
> > +
> > + # no vars
> > + check_script('', None)
> > +
> > + # two vars
> > + check_script('''fred=123
> > +ernie=456''', 'fred=123\\0ernie=456\\0')
>
> Here according the awk implementation the test result can be
>
> 'fred=123\\0ernie=456\\0' => creation order
>
> 'ernie=456\\0fred=123\\0' => alphabetic order
>
> and perhaps other order for other awk ?
>
>
> do you think you can have a solution with POSIX awk ?
> today I found only solution for gawk:
>
>
> ---------------------------- scripts/env2string.awk ----------------------------
> index 1bfe9ed07a..f3215c369a 100644
> @@ -81,7 +81,8 @@ END {
> if (do_output) {
> printf("%s", "#define CONFIG_EXTRA_ENV_TEXT \"")
>
> - # Print out all the variables
> + # Print out all the variables by alphabetic order
> + PROCINFO["sorted_in"] = "@ind_str_asc"
> for (var in vars) {
> env = vars[var]
> print var "=" vars[var] "\\0"
>
>
> But this GNU feature must be avoid,
> see commit 7acb32256831 ("env: Avoid using GNU features in awk")
Thanks for this. I filed:
https://source.denx.de/u-boot/u-boot/-/issues/10
Regards,
Simon
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