| Message ID | 20211001183842.v5.4.Ie78bfbfca0d01d9cba501e127f446ec48e1f7afe@changeid |
|---|---|
| State | Superseded |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | env: Allow environment in text files | expand |
Dear Simon Glass, In message <20211001183842.v5.4.Ie78bfbfca0d01d9cba501e127f446ec48e1f7afe@changeid> you wrote: > 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. > > Also support += to allow variables to be appended to. This is needed when > using the preprocessor. > > Signed-off-by: Simon Glass <sjg@chromium.org> > --- > > (no changes since v4) > > Changes in v4: > - Add documentation in rST format instead of README > - Move use of += to this patch > - Explain that environment variables may not end in + Sorry, I disagree here. There was intentionally only very little restrictions on what a environment variable name should look like - the only exceptions were the '=' and the NUL characters. Adding artificial restrictions now just to enable your custom notation for appending seems not acceptable to me. You might want to chose a different notation or implement a proper parser instead. Thanks. Wolfgang Denk
diff --git a/Makefile b/Makefile index 5c3ba37398f..289a2188cec 100644 --- a/Makefile +++ b/Makefile @@ -1796,7 +1796,12 @@ ENV_FILE := $(if $(wildcard $(ENV_FILE_BOARD)),$(ENV_FILE_BOARD),$(ENV_FILE_COMM quiet_cmd_gen_envp = ENVP $@ cmd_gen_envp = \ if [ -f "$(ENV_FILE)" ]; then \ - cat $(ENV_FILE) >$@; \ + $(CPP) -P $(CFLAGS) -x assembler-with-cpp -D__ASSEMBLY__ \ + -D__UBOOT_CONFIG__ \ + -I . -I include \ + -I $(srctree)/include -include include/config.h \ + -I$(srctree)/arch/$(ARCH)/include \ + $(ENV_FILE) -o $@; \ else \ echo -n >$@ ; \ fi diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst index 4e0770523eb..426d8f65329 100644 --- a/doc/usage/environment.rst +++ b/doc/usage/environment.rst @@ -39,12 +39,24 @@ and has an equals sign immediately afterwards. Spaces before the = are not permitted. It is a good idea to indent your scripts so that only the 'var=' appears at the start of a line. +To add additional text to a variable you can use var+=value. This text is +merged into the variable during the make process and made available as a +single value to U-Boot. To support this, environment variables may not end +in `+`. + +This file can include C-style comments. Blank lines and multi-line +variables are supported, and you can use normal C preprocessor directives +and CONFIG defines from your board config also. + For example, for snapper9260 you would create a text file called `board/bluewater/env/snapper9260.env` containing the environment text. Example:: stdout=serial + #ifdef CONFIG_LCD + stdout+=,lcd + #endif bootcmd= /* U-Boot script for booting */ diff --git a/scripts/env2string.awk b/scripts/env2string.awk index 661defdc350..6de3e3dd87e 100644 --- a/scripts/env2string.awk +++ b/scripts/env2string.awk @@ -29,6 +29,12 @@ NF { } var = arr[1] env = arr[2] + + # Deal with += + if (match(var, "(.*)[+]$", var_arr)) { + var = var_arr[1] + env = vars[var] env + } } else { # Change newline to \n env = env "\\n" $0;
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. Also support += to allow variables to be appended to. This is needed when using the preprocessor. Signed-off-by: Simon Glass <sjg@chromium.org> --- (no changes since v4) Changes in v4: - Add documentation in rST format instead of README - Move use of += to this patch - Explain that environment variables may not end in + Changes in v3: - Define __UBOOT_CONFIG__ when collecting environment files Changes in v2: - Add separate patch to enable C preprocessor for environment files - Enable var+=value form to simplify composing variables in multiple steps Makefile | 7 ++++++- doc/usage/environment.rst | 12 ++++++++++++ scripts/env2string.awk | 6 ++++++ 3 files changed, 24 insertions(+), 1 deletion(-)