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

View File

@ -23,6 +23,10 @@ work on this 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.
For a volatile rootfs, you have to slightly adjust the configuration:
@ -51,16 +55,22 @@ Result of the build
After building, you should obtain this tree:
output/images/
+-- rootfs.tar
+-- rpi-firmware
+-- rootfs.tar [0]
+-- rpi-firmware/
| +-- bcm2708-rpi-b.dtb [1]
| +-- bcm2708-rpi-b-plus.dtb [1]
| +-- bootcode.bin
| +-- config.txt
| +-- fixup.dat
| `-- start.elf
`-- zImage
Note for Volatile: rootfs.tar will only be there if you kept
"tar the root filesystem" option selected in "Filesystem images".
[0] Note for Volatile: rootfs.tar will only be there if you kept
"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
==================
@ -89,17 +99,30 @@ Install the binaries to the SDCard
At the root of the boot partition, the RaspberryPi must find the following
files:
* bcm2708-rpi-b.dtb [2]
* bcm2708-rpi-b-plus.dtb [2]
* bootcode.bin
* config.txt
* fixup.dat
* start.elf
* zImage
[2] Only needed if your kernel has support for the Device Tree.
For example:
$ 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
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:
kernel=zImage