Merge branch '2021-11-16-env-rework' into next

To quote Simon:

One barrier to completing the 7-year-long Kconfig migration is that
the default environment is implemented using ad-hoc CONFIG options.
At present U-Boot environment variables, and thus scripts, are defined
by CONFIG_EXTRA_ENV_SETTINGS.

It is not really feasible to move the environment to Kconfig as it is
hundreds of lines of text in some cases.

Even considering the current situation, it is painful to add large
amounts of text to the config-header 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.

This is already supported by the CONFIG_USE_DEFAULT_ENV_FILE feature. But
that does not support use of CONFIG options or comments, so is best suited
for use by other build systems wanting to define the U-Boot environment.

Add a feature that brings in a .env file associated with the board
config, if present. To use it, create a file board/<vendor>/<board>.env or
use CONFIG_ENV_SOURCE_FILE to set a filename.

The environment variables should be of the form "var=value". Values can
extend to multiple lines. This series converts the existing environment
documentation to rST and updates it to explain how to use this.

1 files changed, 107 insertions, 0 deletions

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')
+
+    # blank lines
+    check_script('''fred=123
+
+
+ernie=456
+
+''', 'fred=123\\0ernie=456\\0')
+
+    # append
+    check_script('''fred=123
+ernie=456
+fred+= 456''', 'fred=123 456\\0ernie=456\\0')
+
+    # append from empty
+    check_script('''fred=
+ernie=456
+fred+= 456''', 'fred= 456\\0ernie=456\\0')
+
+    # variable with + in it
+    check_script('fred+ernie=123', 'fred+ernie=123\\0')
+
+    # ignores variables that are empty
+    check_script('''fred=
+fred+=
+ernie=456''', 'ernie=456\\0')
+
+    # single-character env name
+    check_script('''f=123
+e=456
+f+= 456''', 'e=456\\0f=123 456\\0')
+
+    # contains quotes
+    check_script('''fred="my var"
+ernie=another"''', 'fred=\\"my var\\"\\0ernie=another\\"\\0')
+
+    # variable name ending in +
+    check_script('''fred\\+=my var
+fred++= again''', 'fred+=my var again\\0')
+
+    # variable name containing +
+    check_script('''fred+jane=both
+fred+jane+=again
+ernie=456''', 'fred+jane=bothagain\\0ernie=456\\0')
+
+    # multi-line vars - new vars always start at column 1
+    check_script('''fred=first
+ second
+\tthird with tab
+
+   after blank
+ confusing=oops
+ernie=another"''', 'fred=first second third with tab after blank confusing=oops\\0ernie=another\\"\\0')
+
+    # real-world example
+    check_script('''ubifs_boot=
+	env exists bootubipart ||
+		env set bootubipart UBI;
+	env exists bootubivol ||
+		env set bootubivol boot;
+	if ubi part ${bootubipart} &&
+		ubifsmount ubi${devnum}:${bootubivol};
+	then
+		devtype=ubi;
+		run scan_dev_for_boot;
+	fi
+''',
+        'ubifs_boot=env exists bootubipart || env set bootubipart UBI; '
+        'env exists bootubivol || env set bootubivol boot; '
+        'if ubi part ${bootubipart} && ubifsmount ubi${devnum}:${bootubivol}; '
+        'then devtype=ubi; run scan_dev_for_boot; fi\\0')