From: Simon Glass <s...@chromium.org>
Standard passage provides for a bloblist to be passed from one firmware
phase to the next. That can be used to pass the devicetree along as well.
If CONFIG_OF_BOARD is defined, a board custom routine will provide a
bloblist or a specified memory address to retrieve the devicetree at
runtime.
A devicetree from a bloblist is prioritized than the one from specified
memory region.
Tests for this will be added as part of the Universal Payload work.
Signed-off-by: Simon Glass <s...@chromium.org>
Co-developed-by: Raymond Mao <raymond....@linaro.org>
Signed-off-by: Raymond Mao <raymond....@linaro.org>
---
Changes in v2
- New patch file created for v2.
Amended from the original patch
"[v2,30/32] fdt: Allow the devicetree to come from a bloblist".
Remove CONFIG_OF_BLOBLIST and FDTSRC_BLOBLIST, a DTB from a previous
loader is defined by CONFIG_OF_BOARD. The DTB can be located either in the
bloblist or from a specified memory address.
doc/develop/devicetree/control.rst | 8 +++--
dts/Kconfig | 9 ++++--
include/fdtdec.h | 3 +-
lib/fdtdec.c | 52 +++++++++++++++++++++++-------
4 files changed, 53 insertions(+), 19 deletions(-)
diff --git a/doc/develop/devicetree/control.rst
b/doc/develop/devicetree/control.rst
index cbb65c9b17..a7f0f87841 100644
--- a/doc/develop/devicetree/control.rst
+++ b/doc/develop/devicetree/control.rst
@@ -104,9 +104,11 @@ in u-boot.bin so you can still just flash u-boot.bin onto
your board. If you are
using CONFIG_SPL_FRAMEWORK, then u-boot.img will be built to include the device
tree binary.
-If CONFIG_OF_BOARD is defined, a board-specific routine will provide the
-devicetree at runtime, for example if an earlier bootloader stage creates
-it and passes it to U-Boot.
+If CONFIG_OF_BOARD is defined, a board-specific routine will provide a bloblist
+or a specified memory region to retrieve the devicetree at runtime, for example
+if an earlier bootloader stage creates it and passes it to U-Boot.
+A devicetree from a bloblist is prioritized than the one from a specified
memory
+region.
If CONFIG_SANDBOX is defined, then it will be read from a file on
startup. Use the -d flag to U-Boot to specify the file to read, -D for the
diff --git a/dts/Kconfig b/dts/Kconfig
index 00c0aeff89..4faf4ba633 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -110,8 +110,13 @@ config OF_BOARD
default y if SANDBOX || OF_HAS_PRIOR_STAGE
help
If this option is enabled, the device tree is provided at runtime by
- a custom function called board_fdt_blob_setup(). The board must
- implement this function if it wishes to provide special behaviour.
+ bloblist via a custom function called board_bloblist_from_boot_arg()
+ or a memory region from a custom function called
+ board_fdt_blob_setup(). The board must implement either these
+ functions if it wishes to provide special behaviour.
+
+ A devicetree from a bloblist is prioritized then the one from a
+ specified memory region if the board provides both methods.
With this option, the device tree build by U-Boot may be overridden or
ignored. See OF_HAS_PRIOR_STAGE.
diff --git a/include/fdtdec.h b/include/fdtdec.h
index bd1149f46d..0824fe1359 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -72,14 +72,13 @@ struct bd_info;
* U-Boot is packaged as an ELF file, e.g. for debugging purposes
* @FDTSRC_ENV: Provided by the fdtcontroladdr environment variable. This
should
* be used for debugging/development only
- * @FDTSRC_NONE: No devicetree at all
*/
enum fdt_source_t {
FDTSRC_SEPARATE,
FDTSRC_FIT,
FDTSRC_BOARD,
FDTSRC_EMBED,
- FDTSRC_ENV,
+ FDTSRC_ENV
};
/*
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 7a69167648..025baca4a4 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -7,7 +7,11 @@
*/
#ifndef USE_HOSTCC
+
+#define LOG_CATEGORY LOGC_DT
+
#include <common.h>
+#include <bloblist.h>
#include <boot_fit.h>
#include <display_options.h>
#include <dm.h>
@@ -86,7 +90,7 @@ static const char *const fdt_src_name[] = {
[FDTSRC_FIT] = "fit",
[FDTSRC_BOARD] = "board",
[FDTSRC_EMBED] = "embed",
- [FDTSRC_ENV] = "env",
+ [FDTSRC_ENV] = "env"
};
const char *fdtdec_get_srcname(void)
@@ -1665,21 +1669,45 @@ int fdtdec_setup(void)
{
int ret;
- /* The devicetree is typically appended to U-Boot */
- if (IS_ENABLED(CONFIG_OF_SEPARATE)) {
- gd->fdt_blob = fdt_find_separate();
- gd->fdt_src = FDTSRC_SEPARATE;
- } else { /* embed dtb in ELF file for testing / development */
- gd->fdt_blob = dtb_dt_embedded();
- gd->fdt_src = FDTSRC_EMBED;
- }
-
- /* Allow the board to override the fdt address. */
+ /*
+ * The devicetree is typically appended to U-Boot.
+ * Option 1: From bloblist.
+ * Option 2: From a specified memory address.
+ */
if (IS_ENABLED(CONFIG_OF_BOARD)) {
- gd->fdt_blob = board_fdt_blob_setup(&ret);
+ /*
+ * DTB is from board.
+ * Either from bloblist or a platform specified memory.
+ */
+ ret = bloblist_maybe_init();
if (ret)
return ret;
+
+ /* Check if a DTB exists in bloblist first */
+ if (IS_ENABLED(CONFIG_BLOBLIST)) {
+ gd->fdt_blob = bloblist_find(BLOBLISTT_CONTROL_FDT, 0);
+ if (gd->fdt_blob) {
+ log_info("Fdt from bloblist at 0x%lx\n",
+ (unsigned long)gd->fdt_blob);
+ }
+ }
+ if (!gd->fdt_blob) {
+ /* Apply DTB from a platform specified memory */
+ gd->fdt_blob = board_fdt_blob_setup(&ret);
+ if (ret)
+ return ret;
+ log_info("Fdt from memory at 0x%lx\n",
+ (unsigned long)gd->fdt_blob);
+ }
gd->fdt_src = FDTSRC_BOARD;
+ } else {
+ if (IS_ENABLED(CONFIG_OF_SEPARATE)) {
+ gd->fdt_blob = fdt_find_separate();
+ gd->fdt_src = FDTSRC_SEPARATE;
+ } else { /* embed dtb in ELF file for testing / development */
+ gd->fdt_blob = dtb_dt_embedded();
+ gd->fdt_src = FDTSRC_EMBED;
+ }
}
/* Allow the early environment to override the fdt address */
--
2.25.1
