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authorMaxime Ripard <maxime.ripard@free-electrons.com>2016-07-05 10:26:45 +0200
committerTom Rini <trini@konsulko.com>2016-08-20 11:35:05 -0400
commite6628ad7b99b285b25147366c68a7b956e362878 (patch)
treec815eff9dc136d99f0d6577e37f5c0571daefda8 /cmd
parentddf67f71352be56d98f0e5bcf851146e54d764ad (diff)
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cmd: fdt: add fdt overlay application subcommand
The device tree overlays are a good way to deal with user-modifyable boards or boards with some kind of an expansion mechanism where we can easily plug new board in (like the BBB or the raspberry pi). However, so far, the usual mechanism to deal with it was to have in Linux some driver detecting the expansion boards plugged in and then request these overlays using the firmware interface. That works in most cases, but in some cases, you might want to have the overlays applied before the userspace comes in. Either because the new board requires some kind of an early initialization, or because your root filesystem is accessed through that expansion board. The easiest solution in such a case is to simply have the component before Linux applying that overlay, removing all these drawbacks. Reviewed-by: Stefan Agner <stefan@agner.ch> Acked-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Acked-by: Simon Glass <sjg@chromium.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Diffstat (limited to 'cmd')
-rw-r--r--cmd/fdt.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/cmd/fdt.c b/cmd/fdt.c
index 0f5923e..58af772 100644
--- a/cmd/fdt.c
+++ b/cmd/fdt.c
@@ -639,6 +639,27 @@ static int do_fdt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
#endif
}
+#ifdef CONFIG_OF_LIBFDT_OVERLAY
+ /* apply an overlay */
+ else if (strncmp(argv[1], "ap", 2) == 0) {
+ unsigned long addr;
+ struct fdt_header *blob;
+
+ if (argc != 3)
+ return CMD_RET_USAGE;
+
+ if (!working_fdt)
+ return CMD_RET_FAILURE;
+
+ addr = simple_strtoul(argv[2], NULL, 16);
+ blob = map_sysmem(addr, 0);
+ if (!fdt_valid(&blob))
+ return CMD_RET_FAILURE;
+
+ if (fdt_overlay_apply(working_fdt, blob))
+ return CMD_RET_FAILURE;
+ }
+#endif
/* resize the fdt */
else if (strncmp(argv[1], "re", 2) == 0) {
fdt_shrink_to_minimum(working_fdt);
@@ -1025,6 +1046,9 @@ static int fdt_print(const char *pathp, char *prop, int depth)
#ifdef CONFIG_SYS_LONGHELP
static char fdt_help_text[] =
"addr [-c] <addr> [<length>] - Set the [control] fdt location to <addr>\n"
+#ifdef CONFIG_OF_LIBFDT_OVERLAY
+ "fdt apply <addr> - Apply overlay to the DT\n"
+#endif
#ifdef CONFIG_OF_BOARD_SETUP
"fdt boardsetup - Do board-specific set up\n"
#endif