fdt: Pass the device serial number through devicetree

Before device-tree, the device serial number used to be passed to the kernel using ATAGs (on ARM). This is now deprecated and all the handover to the kernel should now be done using device-tree. Thus, this passes the serial-number property to the kernel using the serial-number property of the root node, as expected by the kernel. The serial number is a string that somewhat represents the device's serial number. It might come from some form of storage (e.g. an eeprom) and be programmed at factory-time by the manufacturer or come from identification bits available in e.g. the SoC. Signed-off-by: Paul Kocialkowski <contact@paulk.fr> Reviewed-by: Simon Glass <sgj@chromium.org>

fdt: Pass the device serial number through devicetree
Before device-tree, the device serial number used to be passed to the kernel using ATAGs (on ARM). This is now deprecated and all the handover to the kernel should now be done using device-tree. Thus, this passes the serial-number property to the kernel using the serial-number property of the root node, as expected by the kernel. The serial number is a string that somewhat represents the device's serial number. It might come from some form of storage (e.g. an eeprom) and be programmed at factory-time by the manufacturer or come from identification bits available in e.g. the SoC. Signed-off-by: Paul Kocialkowski <contact@paulk.fr> Reviewed-by: Simon Glass <sgj@chromium.org>
Paul Kocialkowski · Simon Glass
1 parent d8abb46b37
Showing 4 changed files with 34 additions and 0 deletions Side-by-side Diff
common/fdt_support.c
common/image-fdt.c
doc/device-tree-bindings/root.txt
include/fdt_support.h
@@ -194,6 +194,31 @@
 		return fdt_setprop_u32(fdt, nodeoffset, name, (uint32_t)val);
 }
  
+int fdt_root(void *fdt)
+{
+	char *serial;
+	int err;
+
+	err = fdt_check_header(fdt);
+	if (err < 0) {
+		printf("fdt_root: %s\n", fdt_strerror(err));
+		return err;
+	}
+
+	serial = getenv("serial#");
+	if (serial) {
+		err = fdt_setprop(fdt, 0, "serial-number", serial,
+				  strlen(serial) + 1);
+
+		if (err < 0) {
+			printf("WARNING: could not set serial-number %s.\n",
+			       fdt_strerror(err));
+			return err;
+		}
+	}
+
+	return 0;
+}
  
 int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end)
 {
@@ -471,6 +471,10 @@
 	int ret = -EPERM;
 	int fdt_ret;
  
+	if (fdt_root(blob) < 0) {
+		printf("ERROR: root node setup failed\n");
+		goto err;
+	}
 	if (fdt_chosen(blob) < 0) {
 		printf("ERROR: /chosen node create failed\n");
 		goto err;
+The root node
+
+Optional properties:
+  - serial-number : a string representing the device's serial number
@@ -16,6 +16,7 @@
 				const char *prop, const u32 dflt);
 u32 fdt_getprop_u32_default(const void *fdt, const char *path,
 				const char *prop, const u32 dflt);
+int fdt_root(void *fdt);
 int fdt_chosen(void *fdt);
 int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end);
 void do_fixup_by_path(void *fdt, const char *path, const char *prop,
...	...	@@ -194,6 +194,31 @@
194	194	return fdt_setprop_u32(fdt, nodeoffset, name, (uint32_t)val);
195	195	}
196	196
	197	+int fdt_root(void *fdt)
	198	+{
	199	+ char *serial;
	200	+ int err;
	201	+
	202	+ err = fdt_check_header(fdt);
	203	+ if (err < 0) {
	204	+ printf("fdt_root: %s\n", fdt_strerror(err));
	205	+ return err;
	206	+ }
	207	+
	208	+ serial = getenv("serial#");
	209	+ if (serial) {
	210	+ err = fdt_setprop(fdt, 0, "serial-number", serial,
	211	+ strlen(serial) + 1);
	212	+
	213	+ if (err < 0) {
	214	+ printf("WARNING: could not set serial-number %s.\n",
	215	+ fdt_strerror(err));
	216	+ return err;
	217	+ }
	218	+ }
	219	+
	220	+ return 0;
	221	+}
197	222
198	223	int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end)
199	224	{
...	...	@@ -471,6 +471,10 @@
471	471	int ret = -EPERM;
472	472	int fdt_ret;
473	473
	474	+ if (fdt_root(blob) < 0) {
	475	+ printf("ERROR: root node setup failed\n");
	476	+ goto err;
	477	+ }
474	478	if (fdt_chosen(blob) < 0) {
475	479	printf("ERROR: /chosen node create failed\n");
476	480	goto err;
	1	+The root node
	2	+
	3	+Optional properties:
	4	+ - serial-number : a string representing the device's serial number
...	...	@@ -16,6 +16,7 @@
16	16	const char *prop, const u32 dflt);
17	17	u32 fdt_getprop_u32_default(const void fdt, const char path,
18	18	const char *prop, const u32 dflt);
	19	+int fdt_root(void *fdt);
19	20	int fdt_chosen(void *fdt);
20	21	int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end);
21	22	void do_fixup_by_path(void fdt, const char path, const char *prop,