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(-)
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;