diff options
| author | Rasmus Villemoes | 2021-04-21 11:06:54 +0200 |
|---|---|---|
| committer | Tom Rini | 2021-05-04 11:50:50 -0400 |
| commit | 95fd9772011f29fad2c40fbc3060b5dac042152c (patch) | |
| tree | e06d8d10b7e5cd0b011372786ae918067b982d3e /include | |
| parent | 1cbfed8d3e9254d7e2a9466498ef867f7cb3f4cd (diff) | |
env: allow environment to be amended from control dtb
It can be useful to use the same U-Boot binary for multiple purposes,
say the normal one, one for developers that allow breaking into the
U-Boot shell, and one for use during bootstrapping which runs a
special-purpose bootcmd. Or one can have several board variants that
can share almost all boot logic, but just needs a few tweaks in the
variables used by the boot script.
To that end, allow the control dtb to contain a /config/enviroment
node (or whatever one puts in fdt_env_path variable), whose
property/value pairs are used to update the run-time environment after
it has been loaded from its persistent location.
The indirection via fdt_env_path is for maximum flexibility - for
example, should the user wish (or board logic dictate) that the values
in the DTB should no longer be applied, one simply needs to delete the
fdt_env_path variable; that can even be done automatically by
including a
fdt_env_path = "";
property in the DTB node.
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/env.h | 15 | ||||
| -rw-r--r-- | include/env_default.h | 3 |
2 files changed, 18 insertions, 0 deletions
diff --git a/include/env.h b/include/env.h index b5731e4b9a7..d5e2bcb530f 100644 --- a/include/env.h +++ b/include/env.h @@ -375,4 +375,19 @@ int env_get_char(int index); * This is used for those unfortunate archs with crappy toolchains */ void env_reloc(void); + + +/** + * env_import_fdt() - Import environment values from device tree blob + * + * This uses the value of the environment variable "env_fdt_path" as a + * path to an fdt node, whose property/value pairs are added to the + * environment. + */ +#ifdef CONFIG_ENV_IMPORT_FDT +void env_import_fdt(void); +#else +static inline void env_import_fdt(void) {} +#endif + #endif diff --git a/include/env_default.h b/include/env_default.h index ea31a8eddfa..1ddd64ba8ff 100644 --- a/include/env_default.h +++ b/include/env_default.h @@ -103,6 +103,9 @@ const uchar default_environment[] = { #ifdef CONFIG_SYS_SOC "soc=" CONFIG_SYS_SOC "\0" #endif +#ifdef CONFIG_ENV_IMPORT_FDT + "env_fdt_path=" CONFIG_ENV_FDT_PATH "\0" +#endif #endif #if defined(CONFIG_BOOTCOUNT_BOOTLIMIT) && (CONFIG_BOOTCOUNT_BOOTLIMIT > 0) "bootlimit=" __stringify(CONFIG_BOOTCOUNT_BOOTLIMIT)"\0" |