From cc832b676456c11cd730dd75f0c122991268e64d Mon Sep 17 00:00:00 2001 From: Adrian Freihofer Date: Tue, 17 Feb 2026 17:39:11 +0100 Subject: siemens: capricorn: protect environment With ENV_WRITEABLE_LIST only specific environment variables lisetd in CFG_ENV_FLAGS_LIST_STATIC are read from the u-boot environment storage. All other environment variables are set to default values and are not written back to the storage. The u-boot environment usually stays for the lifetime of the product. There is no A/B copy mechanism as for the firmware itself. That means that incompatible changes to environment variables in future u-boot versions may lead to serious issues if the old environment is used with a new u-boot version or vice versa. Having this protection in place ensures that only a limited set of environment variables are persisted across u-boot versions. All the macros not listed in CFG_ENV_FLAGS_LIST_STATIC are now part of the u-boot binary which is redundant and immutable. This guarantees that the u-boot version and the default values of these environment variables are always in sync and cannot be changed at runtime. ustate and rastate are not relevant for u-boot itself. ustate is used by swupdate which persists the transaction state in the environment. rastate is a similar variable used by another user space application. Signed-off-by: Adrian Freihofer Signed-off-by: Heiko Schocher Reviewed-by: Peng Fan Signed-off-by: Adrian Freihofer Signed-off-by: Heiko Schocher Reviewed-by: Peng Fan --- include/configs/capricorn-common.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include') diff --git a/include/configs/capricorn-common.h b/include/configs/capricorn-common.h index 7120a44d186..ee13d2ab950 100644 --- a/include/configs/capricorn-common.h +++ b/include/configs/capricorn-common.h @@ -38,6 +38,19 @@ #define CFG_EXTRA_ENV_SETTINGS \ AHAB_ENV +#ifdef CONFIG_ENV_WRITEABLE_LIST +#define CFG_ENV_FLAGS_LIST_STATIC \ + "bootcount:dw," \ + "bootdelay:sw," \ + "bootlimit:dw," \ + "partitionset_active:sw," \ + "rastate:dw," \ + "sig_a:sw,sig_b:sw," \ + "target_env:sw," \ + "upgrade_available:dw," \ + "ustate:dw" +#endif + /* Default location for tftp and bootm */ /* On CCP board, USDHC1 is for eMMC */ -- cgit v1.3.1