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 <s...@chromium.org>
Reviewed-by: Marek Behún <marek.be...@nic.cz>
Tested-by: Marek Behún <marek.be...@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")
Regard
Patrick Delaunay
