[PATCH v4 1/5] common: add $global.serial_number with device tree fixup

[Oleksij Rempel]

From: Ahmad Fatoum <a.fatoum at pengutronix.de>

This new variable can be set by boards from C code or from the
environment to change the serial number fixed up into the kernel device
tree.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel at pengutronix.de>
---
 common/Kconfig   |  5 +++++
 common/misc.c    | 16 ++++++++++++++++
 common/oftree.c  |  9 +++++++++
 include/common.h |  3 +++
 4 files changed, 33 insertions(+)

diff --git a/common/Kconfig b/common/Kconfig
index f7a6a96e87..e77e0c78c5 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -1066,6 +1066,11 @@ config MACHINE_ID
 	  Note: if no hashable information is available no machine id will be passed
 	  to the kernel.
 
+config SERIAL_NUMBER_FIXUP
+	bool "fix up board serial number"
+	help
+	  fixup serial number supplied by board code into device tree
+
 config SYSTEMD_OF_WATCHDOG
 	bool "inform devicetree-enabled kernel of used watchdog"
 	depends on WATCHDOG && OFTREE && FLEXIBLE_BOOTARGS
diff --git a/common/misc.c b/common/misc.c
index 226635f0d4..3b3bc05bfd 100644
--- a/common/misc.c
+++ b/common/misc.c
@@ -149,6 +149,7 @@ EXPORT_SYMBOL(barebox_get_model);
 BAREBOX_MAGICVAR(global.model, "Product name of this hardware");
 
 static char *hostname;
+static char *serial_number;
 
 /*
  * The hostname is supposed to be the shortname of a board. It should
@@ -179,6 +180,21 @@ EXPORT_SYMBOL(barebox_set_hostname_no_overwrite);
 BAREBOX_MAGICVAR(global.hostname,
 		"shortname of the board. Also used as hostname for DHCP requests");
 
+void barebox_set_serial_number(const char *__serial_number)
+{
+	globalvar_add_simple_string("serial_number", &serial_number);
+
+	free(serial_number);
+	serial_number = xstrdup(__serial_number);
+}
+
+const char *barebox_get_serial_number(void)
+{
+	return serial_number;
+}
+
+BAREBOX_MAGICVAR(global.serial_number, "Board serial number");
+
 void __noreturn panic(const char *fmt, ...)
 {
 	va_list args;
diff --git a/common/oftree.c b/common/oftree.c
index bce0ff09d6..c6d75055cc 100644
--- a/common/oftree.c
+++ b/common/oftree.c
@@ -207,6 +207,15 @@ static int of_fixup_bootargs(struct device_node *root, void *unused)
 	int instance = reset_source_get_instance();
 	struct device_d *dev;
 
+	if (IS_ENABLED(CONFIG_SERIAL_NUMBER_FIXUP)) {
+		const char *serialno;
+
+		serialno = getenv("global.serial_number");
+		if (serialno)
+			of_property_write_string(root, "serial-number", serialno);
+
+	}
+
 	node = of_create_node(root, "/chosen");
 	if (!node)
 		return -ENOMEM;
diff --git a/include/common.h b/include/common.h
index 4167d4676e..967502a7ab 100644
--- a/include/common.h
+++ b/include/common.h
@@ -126,4 +126,7 @@ const char *barebox_get_hostname(void);
 void barebox_set_hostname(const char *);
 void barebox_set_hostname_no_overwrite(const char *);
 
+const char *barebox_get_serial_number(void);
+void barebox_set_serial_number(const char *);
+
 #endif	/* __COMMON_H_ */
-- 
2.30.2