u-boot-initial-env: rework make target

With LTO enabled the U-Boot initial environment is no longer stored
in an easy accessible section in env/common.o. I.e. the section name
changes from build to build, its content maybe compressed and it is
annotated with additional data.

Drop trying to read the initial env with elf tools from the compiler
specific object file in favour of adding and using a host tool with
the only functionality of printing the initial env to stdout.

See also:
https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com/

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Acked-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/Makefile b/Makefile
index 11efc4180414c0236ee2ef66705ac56cd02f029e..9ec2e12a06affa35e91ed3a677aef795b798a2b5 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -2439,11 +2439,13 @@ endif
        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 quiet_cmd_genenv = GENENV  $@
-cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
-       sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
-       sort --field-separator== -k1,1 --stable $@ -o $@
+cmd_genenv = \
+       $(objtree)/tools/printinitialenv | \
+       sed -e '/^\s*$$/d' | \
+       sort --field-separator== -k1,1 --stable -o $@
 
-u-boot-initial-env: u-boot.bin
+u-boot-initial-env: $(env_h) FORCE
+       $(Q)$(MAKE) $(build)=tools $(objtree)/tools/printinitialenv
        $(call if_changed,genenv)
 
 # Consistency checks

diff --git a/tools/.gitignore b/tools/.gitignore
index d3a93ff294a697d8e2ca37648ff0cdde2cef2a61..28e8ce2a07ad49c024fa97077e3a5db75953d7c5 100644 (file)
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -28,6 +28,7 @@
 /mxsboot
 /ncb
 /prelink-riscv
+/printinitialenv
 /proftool
 /relocate-rela
 /spl_size_limit

diff --git a/tools/Makefile b/tools/Makefile
index 26be0a7ba2eabb9cff10118cfd102ffd285fb8ba..80bc62befcbb6ef09c915832a70df8de29746e51 100644 (file)
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -275,6 +275,10 @@ clean-dirs := lib common
 
 always := $(hostprogs-y)
 
+# Host tool to dump the currently configured default environment,
+# build it on demand, i.e. not add it to 'always'.
+hostprogs-y += printinitialenv
+
 # Generated LCD/video logo
 LOGO_H = $(objtree)/include/bmp_logo.h
 LOGO_DATA_H = $(objtree)/include/bmp_logo_data.h

diff --git a/tools/printinitialenv.c b/tools/printinitialenv.c
new file mode 100644 (file)
index 0000000..c58b234
--- /dev/null
+++ b/tools/printinitialenv.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022
+ * Max Krummenacher, Toradex
+ *
+ * Snippets taken from tools/env/fw_env.c
+ *
+ * This prints the list of default environment variables as currently
+ * configured.
+ *
+ */
+
+#include <stdio.h>
+
+/* Pull in the current config to define the default environment */
+#include <linux/kconfig.h>
+
+#ifndef __ASSEMBLY__
+#define __ASSEMBLY__ /* get only #defines from config.h */
+#include <config.h>
+#undef __ASSEMBLY__
+#else
+#include <config.h>
+#endif
+
+#define DEFAULT_ENV_INSTANCE_STATIC
+#include <generated/environment.h>
+#include <env_default.h>
+
+int main(void)
+{
+       char *env, *nxt;
+
+       for (env = default_environment; *env; env = nxt + 1) {
+               for (nxt = env; *nxt; ++nxt) {
+                       if (nxt >= &default_environment[sizeof(default_environment)]) {
+                               fprintf(stderr, "## Error: environment not terminated\n");
+                               return -1;
+                       }
+               }
+               printf("%s\n", env);
+       }
+       return 0;
+}