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.
Signed-off-by: Simon Glass sjg@chromium.org --- 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 | 3 ++- README | 17 ++++++++++++++++- tools/scripts/env2string.awk | 6 ++++++ 3 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile index 9dae750..89ac4c5 100644 --- a/Makefile +++ b/Makefile @@ -714,7 +714,8 @@ ENV_FILE := $(if $(wildcard $(ENV_FILE_BOARD)),$(ENV_FILE_BOARD),$(ENV_FILE_COMM $(obj)include/generated/environment.in: $(obj)include/generated/autoconf.mk.base \ $(wildcard $(ENV_FILE)) if [ -f "$(ENV_FILE)" ]; then \ - cat $(ENV_FILE) >$@ ; \ + $(CPP) -P $(CFLAGS) -x assembler-with-cpp -D__ASSEMBLY__ \ + -include $(obj)include/config.h $(ENV_FILE) -o $@; \ else \ echo -n >$@ ; \ fi diff --git a/README b/README index 2c8a8c9..6711cd0 100644 --- a/README +++ b/README @@ -4376,12 +4376,25 @@ have a common environment for all vendor boards.
This is a plain text file where you can type your environment variables in the form 'var=value'. Blank lines and multi-line variables are supported. +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.
For example, for snapper9260 you would create a text file called board/bluewater/env/snapper9260.env containing the environment text.
+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. +
+stdout=serial +#ifdef CONFIG_LCD +stdout+=,lcd +#endif bootcmd= + /* U-Boot script for booting */ + if [ -z ${tftpserverip} ]; then echo "Use 'setenv tftpserverip a.b.c.d' to set IP address." fi @@ -4390,7 +4403,9 @@ bootcmd= tftpboot ${tftpserverip}: bootm failed= - echo boot failed - please check your image + /* Print a message when boot fails */ + echo CONFIG_SYS_BOARD boot failed - please check your image + echo Load address is CONFIG_SYS_LOAD_ADDR <<<
The resulting environment can be exported and importing using the diff --git a/tools/scripts/env2string.awk b/tools/scripts/env2string.awk index 2d167c0..d647cf3 100644 --- a/tools/scripts/env2string.awk +++ b/tools/scripts/env2string.awk @@ -23,6 +23,12 @@ BEGIN { } var = arr[1] env = arr[2] + + # Deal with += + if (match(var, "(.*)[+]$", var_arr)) { + var = var_arr[1] + env = vars[var] env + } } else { # Change newline to \n env = env "\n" $0;