[U-Boot] [PATCH v2 3/5] Allow U-Boot scripts to be placed in a .env file

Simon Glass sjg at chromium.org
Mon Jun 24 22:46:03 CEST 2013


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>/env
directory called <board>.env (or common.env if you want the same
environment for all boards).

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.

Comments are not permitted in the environment with this commit.

Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v2:
- Add additional include to env_embedded to deal with its dirty trick
- Add dependency rule so that the environment is rebuilt when it changes
- Add information and updated example script to README
- Move .env file from include/configs to board/
- Use awk script to process environment since it is much easier on the brain

 Makefile                     | 30 +++++++++++++++++++++++++++++-
 README                       | 34 ++++++++++++++++++++++++++++++++++
 common/env_embedded.c        |  1 +
 config.mk                    |  2 ++
 include/env_default.h        |  2 ++
 mkconfig                     |  6 ++++++
 tools/scripts/env2string.awk | 43 +++++++++++++++++++++++++++++++++++++++++++
 7 files changed, 117 insertions(+), 1 deletion(-)
 create mode 100644 tools/scripts/env2string.awk

diff --git a/Makefile b/Makefile
index 693b3f2..9dae750 100644
--- a/Makefile
+++ b/Makefile
@@ -695,7 +695,7 @@ $(obj)include/autoconf.mk.dep: $(obj)include/config.h include/common.h
 	$(CC) -x c -DDO_DEPS_ONLY -M $(CFLAGS) $(CPPFLAGS) \
 		-MQ $(obj)include/autoconf.mk include/common.h > $@
 
-$(obj)include/autoconf.mk: $(obj)include/config.h
+$(obj)include/generated/autoconf.mk.base: $(obj)include/config.h
 	@$(XECHO) Generating $@ ; \
 	set -e ; \
 	: Extract the config macros ; \
@@ -703,6 +703,34 @@ $(obj)include/autoconf.mk: $(obj)include/config.h
 		sed -n -f tools/scripts/define2mk.sed > $@.tmp && \
 	mv $@.tmp $@
 
+# We expect '<board>.env' but failing that will use 'common.env'
+ENV_HEADER := $(obj)include/generated/environment.h
+ENV_DIR := $(if $(VENDOR),$(VENDOR)/env,$(BOARD)/env)
+ENV_FILE_BOARD := $(src)board/${ENV_DIR}/$(BOARD).env
+ENV_FILE_COMMON := $(src)board/${ENV_DIR}/common.env
+ENV_FILE := $(if $(wildcard $(ENV_FILE_BOARD)),$(ENV_FILE_BOARD),$(ENV_FILE_COMMON))
+
+# Regenerate the environment if it changes
+$(obj)include/generated/environment.in: $(obj)include/generated/autoconf.mk.base \
+		$(wildcard $(ENV_FILE))
+	if [ -f "$(ENV_FILE)" ]; then \
+		cat $(ENV_FILE) >$@ ; \
+	else \
+		echo -n >$@ ; \
+	fi
+
+$(obj)include/generated/environment.inc: $(obj)include/generated/environment.in
+	@$(XECHO) Generating $@ ; \
+	set -e ; \
+	: Process the environment file ; \
+	echo -n "CONFIG_EXTRA_ENV_TEXT=" >$@ ; \
+	echo -n "#define CONFIG_EXTRA_ENV_TEXT " >$(ENV_HEADER) ; \
+	awk -f tools/scripts/env2string.awk $< | \
+		tee -a $(ENV_HEADER) >>$@ ; \
+
+$(obj)include/autoconf.mk: $(obj)include/generated/environment.inc
+	cat $(obj)include/generated/autoconf.mk.base $< >$@
+
 $(obj)include/generated/generic-asm-offsets.h:	$(obj)include/autoconf.mk.dep \
 	$(obj)lib/asm-offsets.s
 	@$(XECHO) Generating $@
diff --git a/README b/README
index cd0336c..2c8a8c9 100644
--- a/README
+++ b/README
@@ -4363,6 +4363,40 @@ environment. As long as you don't save the environment you are
 working with an in-memory copy. In case the Flash area containing the
 environment is erased by accident, a default environment is provided.
 
+The default environment is created in include/env_default.h, and can be
+augmented by various CONFIG defines. See that file for details. In
+particular you can define CONFIG_EXTRA_ENV_SETTINGS in your board file
+to add environment variables (see 'CONFIG_EXTRA_ENV_SETTINGS' above
+for details).
+
+It is also possible to create an environment file with the name
+board/<vendor>/env/<board>.env for your board. If that file is not present
+then U-Boot will look for board/<vendor>/env/common.env so that you can
+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.
+
+For example, for snapper9260 you would create a text file called
+board/bluewater/env/snapper9260.env containing the environment text.
+
+>>>
+bootcmd=
+	if [ -z ${tftpserverip} ]; then
+		echo "Use 'setenv tftpserverip a.b.c.d' to set IP address."
+	fi
+
+	usb start; setenv autoload n; bootp;
+	tftpboot ${tftpserverip}:
+	bootm
+failed=
+	echo boot failed - please check your image
+<<<
+
+The resulting environment can be exported and importing using the
+'env export/import -t' commands.
+
+
 Some configuration options can be set using Environment Variables.
 
 List of environment variables (most likely not complete):
diff --git a/common/env_embedded.c b/common/env_embedded.c
index 52bc687..c8e7ee9 100644
--- a/common/env_embedded.c
+++ b/common/env_embedded.c
@@ -24,6 +24,7 @@
 #ifndef __ASSEMBLY__
 #define	__ASSEMBLY__			/* Dirty trick to get only #defines */
 #endif
+#include <generated/environment.h>
 #define	__ASM_STUB_PROCESSOR_H__	/* don't include asm/processor. */
 #include <config.h>
 #undef	__ASSEMBLY__
diff --git a/config.mk b/config.mk
index ddf350e..26385da 100644
--- a/config.mk
+++ b/config.mk
@@ -181,8 +181,10 @@ sinclude $(TOPDIR)/$(CPUDIR)/$(SOC)/config.mk	# include  SoC	specific rules
 endif
 ifdef	VENDOR
 BOARDDIR = $(VENDOR)/$(BOARD)
+ENVDIR=${vendor}/env
 else
 BOARDDIR = $(BOARD)
+ENVDIR=${board}/env
 endif
 ifdef	BOARD
 sinclude $(TOPDIR)/board/$(BOARDDIR)/config.mk	# include board specific rules
diff --git a/include/env_default.h b/include/env_default.h
index 39c5b7c..a394df5 100644
--- a/include/env_default.h
+++ b/include/env_default.h
@@ -137,6 +137,8 @@ const uchar default_environment[] = {
 #ifdef	CONFIG_EXTRA_ENV_SETTINGS
 	CONFIG_EXTRA_ENV_SETTINGS
 #endif
+	/* This is created in the Makefile */
+	CONFIG_EXTRA_ENV_TEXT
 	"\0"
 #ifdef DEFAULT_ENV_INSTANCE_EMBEDDED
 	}
diff --git a/mkconfig b/mkconfig
index 73f852e..7c286a7 100755
--- a/mkconfig
+++ b/mkconfig
@@ -141,8 +141,10 @@ fi
 # Assign board directory to BOARDIR variable
 if [ -z "${vendor}" ] ; then
     BOARDDIR=${board}
+    ENVDIR=${board}/env
 else
     BOARDDIR=${vendor}/${board}
+    ENVDIR=${vendor}/env
 fi
 
 #
@@ -171,10 +173,14 @@ echo "#define CONFIG_SYS_BOARD \"${board}\"" >> config.h
 
 cat << EOF >> config.h
 #define CONFIG_BOARDDIR board/$BOARDDIR
+#define CONFIG_ENVDIR board/$ENVDIR
 #include <config_cmd_defaults.h>
 #include <config_defaults.h>
 #include <configs/${CONFIG_NAME}.h>
 #include <asm/config.h>
+#if !defined(DO_DEPS_ONLY) && !defined(__ASSEMBLY__)
+#include <generated/environment.h>
+#endif
 #include <config_fallbacks.h>
 #include <config_uncmd_spl.h>
 EOF
diff --git a/tools/scripts/env2string.awk b/tools/scripts/env2string.awk
new file mode 100644
index 0000000..2d167c0
--- /dev/null
+++ b/tools/scripts/env2string.awk
@@ -0,0 +1,43 @@
+#
+# Sed script to parse a text file containing an environment and convert it
+# to a C string which can be compiled into U-Boot.
+#
+
+# We begin and end with "
+BEGIN {
+	# env holds the env variable we are currently processing
+	env = "";
+	ORS = ""
+	print "\""
+}
+
+{
+	# Quote quotes
+	gsub("\"", "\\\"")
+
+	# Is this the start of a new environment variable?
+	if (match($0, "^([^ =][^ =]*)=(.*)", arr)) {
+		if (length(env) != 0) {
+			# Record the value of the variable now completed
+			vars[var] = env
+		}
+		var = arr[1]
+		env = arr[2]
+	} else {
+		# Change newline to \n
+		env = env "\\n" $0;
+	}
+}
+
+END {
+	# Record the value of the variable now completed
+	if (length(env) != 0) {
+		vars[var] = env
+	}
+
+	# Print out all the variables
+	for (var in vars) {
+		print var "=" vars[var] "\\0";
+	}
+	print "\""
+}
-- 
1.8.3



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