SPL doesn't write to the environment. These list entries prevent the functions from being garbage-collected, even though nothing will look at the list. This caused several SPL builds (e.g. P2020RDB-PC_NAND) to break due to size limitations and/or unresolved symbols.
A static inline function is used to provide a context in which we can consume the callback, and thus avoid unused function warnings. Signed-off-by: Scott Wood <scottw...@freescale.com> Acked-by: Joe Hershberger <joe.hershber...@gmail.com> --- v2: Update commit message to reflect that some SPLs do use the environment, in a read-only fashion. Also update commit message to indicate that the size of the included functions wasn't the only problem seen. --- include/env_callback.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/env_callback.h b/include/env_callback.h index 47fdc6f..c583120 100644 --- a/include/env_callback.h +++ b/include/env_callback.h @@ -68,8 +68,16 @@ void env_callback_init(ENTRY *var_entry); * when associated through the ".callbacks" environment variable, the callback * will be executed any time the variable is inserted, overwritten, or deleted. */ +#ifdef CONFIG_SPL_BUILD +#define U_BOOT_ENV_CALLBACK(name, callback) \ + static inline void _u_boot_env_noop_##name(void) \ + { \ + (void)callback; \ + } +#else #define U_BOOT_ENV_CALLBACK(name, callback) \ ll_entry_declare(struct env_clbk_tbl, name, env_clbk, env_clbk) = \ {#name, callback} +#endif #endif /* __ENV_CALLBACK_H__ */ -- 1.7.9.5 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot