Re: [PATCH v3 01/12] README: Add doumentation for version information

1 Feb 2021

Hi Simon,
On Mon, Jan 25, 2021 at 1:50 AM Simon Glass sjg@chromium.org wrote:
...
There are quite a few available version options in U-Boot. Add a list of
the available Makefile variables and #defines, along with examples.
Signed-off-by: Simon Glass sjg@chromium.org
Changes in v3:

Move to doc/ and .rst format
Add examples for converting epoch values

doc/Makefile            |  1 -
 doc/develop/index.rst   |  1 +
 doc/develop/version.rst | 93 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 doc/develop/version.rst

diff --git a/doc/Makefile b/doc/Makefile
index a686d4728ec..683e4b56099 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -56,7 +56,6 @@ quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
        PYTHONDONTWRITEBYTECODE=1 \
        BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \
        $(SPHINXBUILD) \

  -W \



Why is this change?
...
    -b $2 \
    -c $(abspath $(srctree)/$(src)) \
    -d $(abspath $(BUILDDIR)/.doctrees/$3) \

diff --git a/doc/develop/index.rst b/doc/develop/index.rst
index beaa64d8d90..ac57fdb8f30 100644
--- a/doc/develop/index.rst
+++ b/doc/develop/index.rst
@@ -13,6 +13,7 @@ Implementation
    global_data
    logging
    menus

version

Debugging
diff --git a/doc/develop/version.rst b/doc/develop/version.rst
new file mode 100644
index 00000000000..6da31a4a1e7
--- /dev/null
+++ b/doc/develop/version.rst
@@ -0,0 +1,93 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. Copyright (c) 2013 The Chromium OS Authors.



+Version information
+===================



+U-Boot releases are named by year and patch level, for example 2020.10 means the
+release that came out in October 2020. Release candidates are tagged every few
+weeks as the project heads to the next release. So 2020.10-rc1 was the first
+release candidate (RC), tagged soon after 2020.07 was released.



+See https://www.denx.de/wiki/view/U-Boot/ReleaseCycle for full details.



+Within the build system, various Makefile variables are created, making use of
+VERSION, PATCHLEVEL and EXTRAVERSION defined at the top of 'Makefile'. There is
+also SUBLEVEL available for downstream use. See also CONFIG_IDENT_STRING.



+Some variables end up in a generated header file at
+include/generated/version_autogenerated.h and can be accessed from C source by
+including <version.h>



+The following are available:


UBOOTRELEASE (Makefile)
 Full release version as a string. If this is not a tagged release, it also


 includes the number of commits since the last tag as well as the the git


 hash.  If there are uncommitted changes a '-dirty' suffix is added too.



 This is written by scripts/setlocalversion (maintained by Linux) to


 include/config/uboot.release and ends up in the UBOOTRELEASE Makefile


 variable.



 Examples::



    2020.10-rc3


    2021.01-rc5-00248-g60dd854f3ba-dirty



PLAIN_VERSION (string #define)
 This is UBOOTRELEASE but available in C source.



 Examples::



    2020.10


    2021.01-rc5-00248-g60dd854f3ba-dirty



UBOOTVERSION (Makefile)
 This holds just the first three components of UBOOTRELEASE (i.e. not the


 git hash, etc.)



 Examples::



    2020.10


    2021.01-rc5



U_BOOT_VERSION (string #define)
 "U-Boot " followed by UBOOTRELEASE, for example::



    U-Boot 2020.10


    U-Boot 2021.01-rc5



 This is used as part of the banner string when U-Boot starts.



U_BOOT_VERSION_STRING (string #define)
 U_BOOT_VERSION followed by build-time information


 and CONFIG_IDENT_STRING.



 Examples::



    U-Boot 2020.10 (Jan 06 2021 - 08:50:36 -0700)


    U-Boot 2021.01-rc5-00248-g60dd854f3ba-dirty (Jan 06 2021 - 08:50:36 -0700) for spring




+Build date/time is also included. See the generated file
+include/generated/timestamp_autogenerated.h for the available
+fields. For example::


#define U_BOOT_DATE "Jan 06 2021"     (US format only)
#define U_BOOT_TIME "08:50:36"        (24-hour clock)
#define U_BOOT_TZ "-0700"             (Time zone in hours)
#define U_BOOT_DMI_DATE "01/06/2021"  (US format only)
#define U_BOOT_BUILD_DATE 0x20210106  (hex yyyymmdd format)
#define U_BOOT_EPOCH 1609948236


+The Epoch is the number of seconds since midnight on 1/1/70. You can convert
+this to a time with::


$ date -u -d @1609948236
Wed 06 Jan 2021 03:50:36 PM UTC
$ date -d 'Wed 06 Jan 2021 03:50:36 PM UTC' +%s
1609948236


+Every time you build U-Boot this will update based on the time
+on your build machine. See 'Reproducible builds' if you want to
+avoid that.
Otherwise,
Reviewed-by: Bin Meng bmeng.cn@gmail.com

    