bootm: adapt help text and naming for bootm.provide_machine_id

The Kconfig help text as well the function name
machine_id_set_bootarg() suggest that enabling the Kconfig option is
sufficient to have barebox pass the machine id to the kernel.

This is not the case, so change the naming/documentation to make this
clearer.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: Bastian Krause <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 13 insertions, 12 deletions

diff --git a/common/Kconfig b/common/Kconfig
index 9b73aa8454..ffdce2f96c 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -989,19 +989,20 @@ config RESET_SOURCE
 	  useful for any kind of system recovery or repair.
 
 config MACHINE_ID
-	bool "pass machine-id to kernel"
+	bool "compute unique machine-id"
 	depends on FLEXIBLE_BOOTARGS
 	depends on SHA1
 	help
-	  Sets the linux.bootargs.machine_id global variable with a value of
-	  systemd.machine_id=UID. The UID is a persistent device-specific
-	  id. It is a hash over device-specific information provided by various
-	  sources.
+	  Compute a persistent machine-specific id and store it to $global.machine_id.
+	  The id is a hash of device-specific information added via
+	  machine_id_set_hashable(). If multiple sources are available, the
+	  information provided by the last call prior to the late initcall
+	  set_machine_id() is used to generate the machine id from. Thus when
+	  updating barebox the machine id might change.
 
-	  Note: if multiple sources provide hashable device-specific information
-	  (via machine_id_set_hashable()) the information provided by the last call
-	  prior to the late initcall set_machine_id() is used to generate the
-	  machine id from. Thus when updating barebox the machine id might change.
+	  global.bootm.provide_machine_id may be used to automatically set
+	  the linux.bootargs.machine_id global variable with a value of
+	  systemd.machine_id=${global.machine_id}
 
 	  Note: if no hashable information is available no machine id will be passed
 	  to the kernel.
diff --git a/common/bootm.c b/common/bootm.c
index f70ef10100..59efc61099 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -856,4 +856,4 @@ BAREBOX_MAGICVAR(global.bootm.verify, "bootm default verify level");
 BAREBOX_MAGICVAR(global.bootm.verbose, "bootm default verbosity level (0=quiet)");
 BAREBOX_MAGICVAR(global.bootm.appendroot, "Add root= option to Kernel to mount rootfs from the device the Kernel comes from (default, device can be overridden via global.bootm.root_dev)");
 BAREBOX_MAGICVAR(global.bootm.root_dev, "bootm default root device (overrides default device in global.bootm.appendroot)");
-BAREBOX_MAGICVAR(global.bootm.provide_machine_id, "If true, add systemd.machine_id= with value of global.machine_id to Kernel");
+BAREBOX_MAGICVAR(global.bootm.provide_machine_id, "If true, append systemd.machine_id=$global.machine_id to Kernel command line");
diff --git a/common/machine_id.c b/common/machine_id.c
index c1309ccafd..6480806cd2 100644
--- a/common/machine_id.c
+++ b/common/machine_id.c
@@ -24,7 +24,7 @@ void machine_id_set_hashable(const void *hashable, size_t len)
 	__machine_id_hashable_length = len;
 }
 
-static int machine_id_set_bootarg(void)
+static int machine_id_set_globalvar(void)
 {
 	struct digest *digest = NULL;
 	unsigned char machine_id[SHA1_DIGEST_SIZE];
@@ -64,6 +64,6 @@ out:
 	return ret;
 
 }
-late_initcall(machine_id_set_bootarg);
+late_initcall(machine_id_set_globalvar);
 
 BAREBOX_MAGICVAR(global.machine_id, "Persistent device-specific, hexadecimal, 32-character id");