174a1dcc96
When building with 'make -s', no output to stdout should be printed.
As Arnd Bergmann reported [1], mkimage shows the detailed information
of the generated images.
I think this should be suppressed by the 'cmd' macro instead of by
individual scripts.
Insert 'exec >/dev/null;' in order to redirect stdout to /dev/null for
silent builds.
[Note about this implementation]
'exec >/dev/null;' may look somewhat tricky, but this has a reason.
Appending '>/dev/null' at the end of command line is a common way for
redirection, so I first tried this:
cmd = @set -e; $(echo-cmd) $(cmd_$(1)) >/dev/null
... but it would not work if $(cmd_$(1)) itself contains a redirection.
For example, cmd_wrap in scripts/Makefile.asm-generic redirects the
output from the 'echo' command into the target file.
It would be expanded into:
echo "#include <asm-generic/$*.h>" > $@ >/dev/null
Then, the target file gets empty because the string will go to /dev/null
instead of $@.
Next, I tried this:
cmd = @set -e; $(echo-cmd) { $(cmd_$(1)); } >/dev/null
The form above would be expanded into:
{ echo "#include <asm-generic/$*.h>" > $@; } >/dev/null
This works as expected. However, it would be a syntax error if
$(cmd_$(1)) is empty.
When CONFIG_TRIM_UNUSED_KSYMS is disabled, $(call cmd,gen_ksymdeps) in
scripts/Makefile.build would be expanded into:
set -e; { ; } >/dev/null
..., which causes an syntax error.
I also tried this:
cmd = @set -e; $(echo-cmd) ( $(cmd_$(1)) ) >/dev/null
... but this causes a syntax error for the same reason.
So, finally I adopted:
cmd = @set -e; $(echo-cmd) exec >/dev/null; $(cmd_$(1))
[1]: https://lore.kernel.org/lkml/20210514135752.2910387-1-arnd@kernel.org/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.