| Message ID | 20210421090655.1458746-2-rasmus.villemoes@prevas.dk |
|---|---|
| State | Accepted |
| Commit | 95fd9772011f29fad2c40fbc3060b5dac042152c |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | allow environment to be updated from dtb | expand |
On Wed, Apr 21, 2021 at 4:07 AM Rasmus Villemoes <rasmus.villemoes@prevas.dk> wrote: > > 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> Cool addition. Acked-by: Joe Hershberger <joe.hershberger@ni.com>
On Wed, Apr 21, 2021 at 11:06:54AM +0200, Rasmus Villemoes wrote: > 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> Applied to u-boot/master, thanks!
diff --git a/common/board_r.c b/common/board_r.c index c835ff8e26..3f82404772 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -459,6 +459,8 @@ static int initr_env(void) else env_set_default(NULL, 0); + env_import_fdt(); + if (IS_ENABLED(CONFIG_OF_CONTROL)) env_set_hex("fdtcontroladdr", (unsigned long)map_to_sysmem(gd->fdt_blob)); diff --git a/env/Kconfig b/env/Kconfig index 08e49c2a47..78c534344f 100644 --- a/env/Kconfig +++ b/env/Kconfig @@ -669,6 +669,24 @@ config DELAY_ENVIRONMENT later by U-Boot code. With CONFIG_OF_CONTROL this is instead controlled by the value of /config/load-environment. +config ENV_IMPORT_FDT + bool "Amend environment by FDT properties" + depends on OF_CONTROL + help + If selected, after the environment has been loaded from its + persistent location, the "env_fdt_path" variable is looked + up and used as a path to a node in the control DTB. The + property/value pairs in that node is then used to update the + run-time environment. This can be useful to use the same + U-Boot binary with different board variants. + +config ENV_FDT_PATH + string "Default value for env_fdt_path variable" + depends on ENV_IMPORT_FDT + default "/config/environment" + help + The initial value of the env_fdt_path variable. + config ENV_APPEND bool "Always append the environment with new data" default n diff --git a/env/common.c b/env/common.c index 49bbb05eec..81e9e0b2aa 100644 --- a/env/common.c +++ b/env/common.c @@ -20,6 +20,7 @@ #include <errno.h> #include <malloc.h> #include <u-boot/crc.h> +#include <dm/ofnode.h> DECLARE_GLOBAL_DATA_PTR; @@ -334,3 +335,32 @@ int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf, return found; } #endif + +#ifdef CONFIG_ENV_IMPORT_FDT +void env_import_fdt(void) +{ + const char *path; + struct ofprop prop; + ofnode node; + int res; + + path = env_get("env_fdt_path"); + if (!path || !path[0]) + return; + + node = ofnode_path(path); + if (!ofnode_valid(node)) { + printf("Warning: device tree node '%s' not found\n", path); + return; + } + + for (res = ofnode_get_first_property(node, &prop); + !res; + res = ofnode_get_next_property(&prop)) { + const char *name, *val; + + val = ofnode_get_property_by_prop(&prop, &name, NULL); + env_set(name, val); + } +} +#endif diff --git a/include/env.h b/include/env.h index b5731e4b9a..d5e2bcb530 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 ea31a8eddf..1ddd64ba8f 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"