From 0df82694776d4497ca3bcfb662a68fd817698e89 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <damien.lemoal@wdc.com>
Date: Fri, 18 Jan 2019 15:49:37 +0900
Subject: Makefile: Add support for device tree compilation

Add rules to compile dts files into dtb files using the device tree
compiler (dtc). A platform can specify the DTS file to compile using
the platform-dtb-y variable. The flattened device tree binary file to be
used for building the final polatform firmware can be specified using
the new FW_PAYLOAD_FDT firmware configuration option to point to the
automatically compiled FDT file. Using the existing FW_PAYLOAD_FDT_PATH
configuration option is still possible and will take precedence over
the FW_PAYLOAD_FDT definition.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 docs/firmware/fw_payload.md | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'docs/firmware')

diff --git a/docs/firmware/fw_payload.md b/docs/firmware/fw_payload.md
index 0e705a2..3a8a14d 100644
--- a/docs/firmware/fw_payload.md
+++ b/docs/firmware/fw_payload.md
@@ -57,6 +57,14 @@ device tree file is specified by the platform (c.f. *FW_PAYLOAD_FDT*),
 then the firmware will expect the FDT to be passed as an argument by
 the prior booting stage.
 
+* **FW_PAYLOAD_FDT** - Path to an internal flattened device tree
+binary file defined by the platform code. The file name must match the
+DTB file name specified in the platform *objects.mk* file with the
+*platform-dtb-y* entry. This option results in *FW_PAYLOAD_FDT_PATH* to
+be automatically set. Specifying *FW_PAYLOAD_FDT_PATH* on the `make`
+command line disables *FW_PAYLOAD_FDT* and the command line specified
+device tree binary file is used for building the final firmware.
+
 * **FW_PAYLOAD_FDT_ADDR** - Address where the FDT passed by the prior
 booting stage or specified by the *FW_PAYLOAD_FDT_PATH* parameter and
 embedded in the *.text* section will be placed before executing the
-- 
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