diff options
| author | Simon Glass | 2014-06-02 22:04:50 -0600 |
|---|---|---|
| committer | Tom Rini | 2014-06-11 16:25:46 -0400 |
| commit | 63b4b5bae52e48528876e13e858ef934ac2e4a3b (patch) | |
| tree | e0143f2b83f7bbba3d30f97785dad6f2624eb932 /doc | |
| parent | 31890ae299bca739c58b311dfced0bb199a5f520 (diff) | |
fdt: Add DEV_TREE_BIN option to specify a device tree binary file
In some cases, an externally-built device tree binary is required to be
attached to U-Boot. An example is when using image signing, since in that
case the .dtb file must include the public keys.
Add a DEV_TREE_BIN option to the Makefile, and update the documentation.
Usage is something like:
make DEV_TREE_BIN=boot/am335x-boneblack-pubkey.dtb
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.fdt-control | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/doc/README.fdt-control b/doc/README.fdt-control index 0ceebe7aa6f..be92d7ae883 100644 --- a/doc/README.fdt-control +++ b/doc/README.fdt-control @@ -122,7 +122,8 @@ This should include your CPU or SOC's device tree file, placed in arch/<arch>/dts, and then make any adjustments required. If CONFIG_OF_EMBED is defined, then it will be picked up and built into -the U-Boot image (including u-boot.bin). +the U-Boot image (including u-boot.bin). This is suitable for debugging +and development only and is not recommended for production devices. If CONFIG_OF_SEPARATE is defined, then it will be built and placed in a u-boot.dtb file alongside u-boot.bin. A common approach is then to @@ -130,7 +131,10 @@ join the two: cat u-boot.bin u-boot.dtb >image.bin -and then flash image.bin onto your board. +and then flash image.bin onto your board. Note that U-Boot creates +u-boot-dtb.bin which does the above step for you also. If you are using +CONFIG_SPL_FRAMEWORK, then u-boot.img will be built to include the device +tree binary. If CONFIG_OF_HOSTFILE is defined, then it will be read from a file on startup. This is only useful for sandbox. Use the -d flag to U-Boot to @@ -138,6 +142,14 @@ specify the file to read. You cannot use more than one of these options at the same time. +To use a device tree file that you have compiled yourself, pass +DEV_TREE_BIN=<filename> to 'make', as in: + + make DEV_TREE_BIN=boot/am335x-boneblack-pubkey.dtb + +Then U-Boot will copy that file to u-boot.dtb, put it in the .img file +if used, and u-boot-dtb.bin. + If you wish to put the fdt at a different address in memory, you can define the "fdtcontroladdr" environment variable. This is the hex address of the fdt binary blob, and will override either of the options. |