[PATCH] smbios: Fix calculating BIOS Release Date

[Heinrich Schuchardt]

On 4/22/21 6:09 PM, Pali Rohár wrote:
> BIOS Release Date must be in format mm/dd/yyyy and must be release date.

%s/BIOS/The SMBIOS/

Please add a reference to the System Management BIOS (SMBIOS) Reference
Specification here an as comment in the code.

> U-Boot currently sets BIOS Release Date from U_BOOT_DMI_DATE macro which is
> generated from current build timestamp.

%s/BIOS/the SMBIOS/

Please, describe in the commit message that you want to achieve
reproducible builds.

>
> Fix this issue by setting U_BOOT_DMI_DATE macro to U-Boot version which is
> better approximation of U-Boot release date than current build timestamp.
> Current U-Boot versioning is in format yyyy.mm so as a day choose 01.
>
> Some operating systems are using BIOS Release Date for detecting when was
> SMBIOS table filled or if it could support some feature (e.g. BIOS from
> 1990 cannot support features invented in 2000). So this change also ensures
> that recompiling U-Boot from same sources but in different year does not
> change behavior of some operating systems.
>
> Macro U_BOOT_DMI_DATE is not used in other file than lib/smbios.c
> so remove it from global autogenerated files and also from Makefile.
>
> Signed-off-by: Pali Rohár <pali at kernel.org>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
>   Makefile                |  2 --
>   doc/develop/version.rst |  1 -
>   lib/smbios.c            | 23 +++++++++++++++++++++++
>   3 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index e423f6de7468..4cd28bce237b 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1832,7 +1832,6 @@ define filechk_timestamp.h
>   			LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DATE "%b %d %C%y"'; \
>   			LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TIME "%T"'; \
>   			LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TZ "%z"'; \
> -			LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DMI_DATE "%m/%d/%Y"'; \
>   			LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_BUILD_DATE 0x%Y%m%d'; \
>   			LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_EPOCH %s'; \
>   		else \
> @@ -1842,7 +1841,6 @@ define filechk_timestamp.h
>   		LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"'; \
>   		LC_ALL=C date +'#define U_BOOT_TIME "%T"'; \
>   		LC_ALL=C date +'#define U_BOOT_TZ "%z"'; \
> -		LC_ALL=C date +'#define U_BOOT_DMI_DATE "%m/%d/%Y"'; \
>   		LC_ALL=C date +'#define U_BOOT_BUILD_DATE 0x%Y%m%d'; \
>   		LC_ALL=C date +'#define U_BOOT_EPOCH %s'; \
>   	fi)
> diff --git a/doc/develop/version.rst b/doc/develop/version.rst
> index a7797db41bb2..066901bcd2d9 100644
> --- a/doc/develop/version.rst
> +++ b/doc/develop/version.rst
> @@ -84,7 +84,6 @@ 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
>
> diff --git a/lib/smbios.c b/lib/smbios.c
> index 9eb226ec9fbd..e5cf05073543 100644
> --- a/lib/smbios.c
> +++ b/lib/smbios.c
> @@ -8,6 +8,7 @@
>   #include <common.h>
>   #include <dm.h>
>   #include <env.h>
> +#include <linux/stringify.h>
>   #include <mapmem.h>
>   #include <smbios.h>
>   #include <sysinfo.h>
> @@ -18,6 +19,28 @@
>   #include <dm/uclass-internal.h>
>   #endif
>
> +/* Safeguard for checking that U_BOOT_VERSION_NUM macros are compatible with U_BOOT_DMI */
> +#if U_BOOT_VERSION_NUM < 2000 || U_BOOT_VERSION_NUM > 2099 || \
> +    U_BOOT_VERSION_NUM_PATCH < 1 || U_BOOT_VERSION_NUM_PATCH > 12
> +#error U_BOOT_VERSION_NUM macros are not compatible with DMI, fix U_BOOT_DMI macros
> +#endif
> +
> +/*
> + * U_BOOT_DMI_DATE contains BIOS Release Date in format mm/dd/yyyy.

Why should we call this DMI_DATE and not SMBIOS_RELEASE_DATE?

Best regards

Heinrich

> + * BIOS Release Date is calculated from U-Boot version and fixed day 01.
> + * So for U-Boot version 2021.04 it is calculated as "04/01/2021".
> + * BIOS Release Date should contain date when code was released
> + * and not when it was built or compiled.
> + */
> +#if U_BOOT_VERSION_NUM_PATCH < 10
> +#define U_BOOT_DMI_MONTH "0" __stringify(U_BOOT_VERSION_NUM_PATCH)
> +#else
> +#define U_BOOT_DMI_MONTH __stringify(U_BOOT_VERSION_NUM_PATCH)
> +#endif
> +#define U_BOOT_DMI_DAY "01"
> +#define U_BOOT_DMI_YEAR __stringify(U_BOOT_VERSION_NUM)
> +#define U_BOOT_DMI_DATE U_BOOT_DMI_MONTH "/" U_BOOT_DMI_DAY "/" U_BOOT_DMI_YEAR
> +
>   DECLARE_GLOBAL_DATA_PTR;
>
>   /**
>