boards/raspberrypi: update readme with Device Tree instructions

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This commit is contained in:
Yann E. MORIN 2015-01-10 14:14:58 +01:00 committed by Thomas Petazzoni
parent 23da43ae12
commit bb60ad9ba4

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@ -23,6 +23,10 @@ work on this defconfig:
$ make raspberrypi_defconfig $ make raspberrypi_defconfig
Alternatively, if you want to test support for the Device Tree:
$ make raspberrypi_dt_defconfig
If you want to use a persistent rootfs, skip to "Build the rootfs", below. If you want to use a persistent rootfs, skip to "Build the rootfs", below.
For a volatile rootfs, you have to slightly adjust the configuration: For a volatile rootfs, you have to slightly adjust the configuration:
@ -51,17 +55,23 @@ Result of the build
After building, you should obtain this tree: After building, you should obtain this tree:
output/images/ output/images/
+-- rootfs.tar +-- rootfs.tar [0]
+-- rpi-firmware +-- rpi-firmware/
| +-- bcm2708-rpi-b.dtb [1]
| +-- bcm2708-rpi-b-plus.dtb [1]
| +-- bootcode.bin | +-- bootcode.bin
| +-- config.txt | +-- config.txt
| +-- fixup.dat | +-- fixup.dat
| `-- start.elf | `-- start.elf
`-- zImage `-- zImage
Note for Volatile: rootfs.tar will only be there if you kept [0] Note for Volatile: rootfs.tar will only be there if you kept
"tar the root filesystem" option selected in "Filesystem images". "tar the root filesystem" option selected in "Filesystem images".
[1] The DTBs (Device Tree Blobs) will only be present if you setup
Buildroot to install the DTBs from the rpi-firmware package, and
will only be used if your kernel has support for the Device Tree.
Prepare you SDCard Prepare you SDCard
================== ==================
@ -89,17 +99,30 @@ Install the binaries to the SDCard
At the root of the boot partition, the RaspberryPi must find the following At the root of the boot partition, the RaspberryPi must find the following
files: files:
* bcm2708-rpi-b.dtb [2]
* bcm2708-rpi-b-plus.dtb [2]
* bootcode.bin * bootcode.bin
* config.txt * config.txt
* fixup.dat * fixup.dat
* start.elf * start.elf
* zImage * zImage
[2] Only needed if your kernel has support for the Device Tree.
For example: For example:
$ cp output/images/rpi-firmware/* /mnt/mountpointboot $ cp output/images/rpi-firmware/* /mnt/mountpointboot
If your kernel does *not* have support for the Device Tree, then install
it with:
$ cp output/images/zImage /mnt/mountpointboot $ cp output/images/zImage /mnt/mountpointboot
If your kernel *does* have support for the Device Tree, then install it
with:
$ ./output/host/usr/bin/mkknlimg output/images/zImage /mnt/mountpointboot/zImage
Note: The kernel image file name is defined in config.txt like this: Note: The kernel image file name is defined in config.txt like this:
kernel=zImage kernel=zImage