cmd: env: Add `indirect` to indirectly set values
This allows an ergonomic-enough approximation of ${!variable} expansion.
This could be used the following way:
```
for target in ${boot_targets}; do
env indirect target_name target_name_${target}
# ...
done
```
Assuming `target_name_mmc0` and similar are set appropriately.
A default value can be optionally provided.
Note: this acts on environment variables, not hush variables.
Signed-off-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: "Marek Behún" <marek.behun@nic.cz>
[trini: Don't enable by default]
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 7bd9546..c5eb71c 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -518,6 +518,9 @@
If enabled, we are allowed to set/print UEFI variables using
"env" command with "-e" option without knowing details.
+config CMD_NVEDIT_INDIRECT
+ bool "env indirect - Sets environment value from another"
+
config CMD_NVEDIT_INFO
bool "env info - print or evaluate environment information"
help
diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index 3bb6e76..53e6b57 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -1018,6 +1018,45 @@
}
#endif
+#if defined(CONFIG_CMD_NVEDIT_INDIRECT)
+static int do_env_indirect(struct cmd_tbl *cmdtp, int flag,
+ int argc, char *const argv[])
+{
+ char *to = argv[1];
+ char *from = argv[2];
+ char *default_value = NULL;
+ int ret = 0;
+
+ if (argc < 3 || argc > 4) {
+ return CMD_RET_USAGE;
+ }
+
+ if (argc == 4) {
+ default_value = argv[3];
+ }
+
+ if (env_get(from) == NULL && default_value == NULL) {
+ printf("## env indirect: Environment variable for <from> (%s) does not exist.\n", from);
+
+ return CMD_RET_FAILURE;
+ }
+
+ if (env_get(from) == NULL) {
+ ret = env_set(to, default_value);
+ }
+ else {
+ ret = env_set(to, env_get(from));
+ }
+
+ if (ret == 0) {
+ return CMD_RET_SUCCESS;
+ }
+ else {
+ return CMD_RET_FAILURE;
+ }
+}
+#endif
+
#if defined(CONFIG_CMD_NVEDIT_INFO)
/*
* print_env_info - print environment information
@@ -1181,6 +1220,9 @@
#if defined(CONFIG_CMD_IMPORTENV)
U_BOOT_CMD_MKENT(import, 5, 0, do_env_import, "", ""),
#endif
+#if defined(CONFIG_CMD_NVEDIT_INDIRECT)
+ U_BOOT_CMD_MKENT(indirect, 3, 0, do_env_indirect, "", ""),
+#endif
#if defined(CONFIG_CMD_NVEDIT_INFO)
U_BOOT_CMD_MKENT(info, 3, 0, do_env_info, "", ""),
#endif
@@ -1265,6 +1307,9 @@
#if defined(CONFIG_CMD_IMPORTENV)
"env import [-d] [-t [-r] | -b | -c] addr [size] [var ...] - import environment\n"
#endif
+#if defined(CONFIG_CMD_NVEDIT_INDIRECT)
+ "env indirect <to> <from> [default] - sets <to> to the value of <from>, using [default] when unset\n"
+#endif
#if defined(CONFIG_CMD_NVEDIT_INFO)
"env info - display environment information\n"
"env info [-d] [-p] [-q] - evaluate environment information\n"