[U-Boot] [PATCH] cmd, fdt: add subcommand "get" to fdt header

Heiko Schocher hs at denx.de
Wed Nov 14 13:12:28 UTC 2018


store fdt header member with name <member> in U-Boot
Environment variable with name <var>.

for example to get the total length of the fdt and store
it in filesize, call:

fdt header get filesize totalsize

For membernames look into fdt header definition at
scripts/dtc/libfdt/libfdt.h

Signed-off-by: Heiko Schocher <hs at denx.de>
---

  cmd/fdt.c | 40 +++++++++++++++++++++++++++++++++++++++-
  1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/cmd/fdt.c b/cmd/fdt.c
index 8a19a3fdbf..cc50f7914d 100644
--- a/cmd/fdt.c
+++ b/cmd/fdt.c
@@ -73,6 +73,40 @@ static int fdt_value_env_set(const void *nodep, int len, const char *var)
  	return 0;
  }

+fdt_member_table[] = {
+	{"magic"},
+	{"totalsize"},
+	{"off_dt_struct"},
+	{"off_dt_strings"},
+	{"off_mem_rsvmap"},
+	{"version"},
+	{"last_comp_version"},
+	{"boot_cpuid_phys"},
+	{"size_dt_strings"},
+	{"size_dt_struct"},
+};
+
+static int fdt_get_header_value(int argc, char * const argv[])
+{
+	fdt32_t *fdtp = (fdt32_t *)working_fdt;
+	ulong val;
+	int i;
+
+	if (argv[2][0] != 'g')
+		return CMD_RET_FAILURE;
+
+	for (i = 0; i < ARRAY_SIZE(fdt_member_table); i++) {
+		if (strcmp(fdt_member_table[i], argv[4]) == 0) {
+			val = fdt32_to_cpu(*fdtp);
+			env_set_hex(argv[3], val);
+			return CMD_RET_SUCCESS;
+		}
+		fdtp++;
+	}
+
+	return CMD_RET_FAILURE;
+}
+
  /*
   * Flattened Device Tree command, see the help for parameter definitions.
   */
@@ -491,6 +525,9 @@ static int do_fdt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  	 * Display header info
  	 */
  	} else if (argv[1][0] == 'h') {
+		if (argc == 5)
+			return fdt_get_header_value(argc, argv);
+
  		u32 version = fdt_version(working_fdt);
  		printf("magic:\t\t\t0x%x\n", fdt_magic(working_fdt));
  		printf("totalsize:\t\t0x%x (%d)\n", fdt_totalsize(working_fdt),
@@ -1090,7 +1127,8 @@ static char fdt_help_text[] =
  	"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"
-	"fdt header                          - Display header info\n"
+	"fdt header [get <var> <member>]     - Display header info\n"
+	"                                      get - get header member <member> and store it in <var>\n"
  	"fdt bootcpu <id>                    - Set boot cpuid\n"
  	"fdt memory <addr> <size>            - Add/Update memory node\n"
  	"fdt rsvmem print                    - Show current mem reserves\n"
-- 
2.13.6


-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de


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