fdt: Add get commands to fdt
Add commands to access data in the fdt. This allows data from a dtb
or itb to be accessed from the shell scripts.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/common/cmd_fdt.c b/common/cmd_fdt.c
index 699441b5..2997452 100644
--- a/common/cmd_fdt.c
+++ b/common/cmd_fdt.c
@@ -47,6 +47,7 @@
static int fdt_valid(void);
static int fdt_parse_prop(char *const*newval, int count, char *data, int *len);
static int fdt_print(const char *pathp, char *prop, int depth);
+static int is_printable_string(const void *data, int len);
/*
* The working_fdt points to our working flattened device tree.
@@ -64,6 +65,34 @@
}
/*
+ * Get a value from the fdt and format it to be set in the environment
+ */
+static int fdt_value_setenv(const void *nodep, int len, const char *var)
+{
+ if (is_printable_string(nodep, len))
+ setenv(var, (void *)nodep);
+ else if (len == 4) {
+ char buf[11];
+
+ sprintf(buf, "0x%08X", *(uint32_t *)nodep);
+ setenv(var, buf);
+ } else if (len%4 == 0 && len <= 20) {
+ /* Needed to print things like sha1 hashes. */
+ char buf[41];
+ int i;
+
+ for (i = 0; i < len; i += sizeof(unsigned int))
+ sprintf(buf + (i * 2), "%08x",
+ *(unsigned int *)(nodep + i));
+ setenv(var, buf);
+ } else {
+ printf("error: unprintable value\n");
+ return 1;
+ }
+ return 0;
+}
+
+/*
* Flattened Device Tree command, see the help for parameter definitions.
*/
int do_fdt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
@@ -253,6 +282,117 @@
return 1;
}
+ /********************************************************************
+ * Get the value of a property in the working_fdt.
+ ********************************************************************/
+ } else if (argv[1][0] == 'g') {
+ char *subcmd; /* sub-command */
+ char *pathp; /* path */
+ char *prop; /* property */
+ char *var; /* variable to store result */
+ int nodeoffset; /* node offset from libfdt */
+ const void *nodep; /* property node pointer */
+ int len = 0; /* new length of the property */
+
+ /*
+ * Parameters: Node path, property, optional value.
+ */
+ if (argc < 5)
+ return CMD_RET_USAGE;
+
+ subcmd = argv[2];
+
+ if (argc < 6 && subcmd[0] != 's')
+ return CMD_RET_USAGE;
+
+ var = argv[3];
+ pathp = argv[4];
+ prop = argv[5];
+
+ nodeoffset = fdt_path_offset(working_fdt, pathp);
+ if (nodeoffset < 0) {
+ /*
+ * Not found or something else bad happened.
+ */
+ printf("libfdt fdt_path_offset() returned %s\n",
+ fdt_strerror(nodeoffset));
+ return 1;
+ }
+
+ if (subcmd[0] == 'n' || (subcmd[0] == 's' && argc == 5)) {
+ int reqIndex = -1;
+ int startDepth = fdt_node_depth(
+ working_fdt, nodeoffset);
+ int curDepth = startDepth;
+ int curIndex = -1;
+ int nextNodeOffset = fdt_next_node(
+ working_fdt, nodeoffset, &curDepth);
+
+ if (subcmd[0] == 'n')
+ reqIndex = simple_strtoul(argv[5], NULL, 16);
+
+ while (curDepth > startDepth) {
+ if (curDepth == startDepth + 1)
+ curIndex++;
+ if (subcmd[0] == 'n' && curIndex == reqIndex) {
+ const char *nodeName = fdt_get_name(
+ working_fdt, nextNodeOffset, NULL);
+
+ setenv(var, (char *)nodeName);
+ return 0;
+ }
+ nextNodeOffset = fdt_next_node(
+ working_fdt, nextNodeOffset, &curDepth);
+ if (nextNodeOffset < 0)
+ break;
+ }
+ if (subcmd[0] == 's') {
+ /* get the num nodes at this level */
+ char buf[11];
+
+ sprintf(buf, "%d", curIndex + 1);
+ setenv(var, buf);
+ } else {
+ /* node index not found */
+ printf("libfdt node not found\n");
+ return 1;
+ }
+ } else {
+ nodep = fdt_getprop(
+ working_fdt, nodeoffset, prop, &len);
+ if (len == 0) {
+ /* no property value */
+ setenv(var, "");
+ return 0;
+ } else if (len > 0) {
+ if (subcmd[0] == 'v') {
+ int ret;
+
+ ret = fdt_value_setenv(nodep, len, var);
+ if (ret != 0)
+ return ret;
+ } else if (subcmd[0] == 'a') {
+ /* Get address */
+ char buf[11];
+
+ sprintf(buf, "0x%08X", (uint32_t)nodep);
+ setenv(var, buf);
+ } else if (subcmd[0] == 's') {
+ /* Get size */
+ char buf[11];
+
+ sprintf(buf, "0x%08X", len);
+ setenv(var, buf);
+ } else
+ return CMD_RET_USAGE;
+ return 0;
+ } else {
+ printf("libfdt fdt_getprop(): %s\n",
+ fdt_strerror(len));
+ return 1;
+ }
+ }
+
/*
* Print (recursive) / List (single level)
*/
@@ -836,6 +976,10 @@
"fdt resize - Resize fdt to size + padding to 4k addr\n"
"fdt print <path> [<prop>] - Recursive print starting at <path>\n"
"fdt list <path> [<prop>] - Print one level starting at <path>\n"
+ "fdt get value <var> <path> <prop> - Get <property> and store in <var>\n"
+ "fdt get name <var> <path> <index> - Get name of node <index> and store in <var>\n"
+ "fdt get addr <var> <path> <prop> - Get start address of <property> and store in <var>\n"
+ "fdt get size <var> <path> [<prop>] - Get size of [<property>] or num nodes and store in <var>\n"
"fdt set <path> <prop> [<val>] - Set <property> [to <val>]\n"
"fdt mknode <path> <node> - Create a new node after <path>\n"
"fdt rm <path> [<prop>] - Delete the node or <property>\n"