zynq: unify readme.txt for all Zynq boards

The readme.txt for the three boards are almost the same, so merge
them into board/zynq/readme.txt.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matt Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/board/zynq/readme.txt b/board/zynq/readme.txt
new file mode 100644
index 000000000..73f8bf336
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+++ b/board/zynq/readme.txt
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+This is the Buildroot support for Zynq boards.  Zynq boards are available from
+Xilinx and some third party vendors, but the build procedure is very similar.
+
+Currently, three boards are natively supported by Buildroot:
+ - Xilinx ZC706 board (zynq_zc706_defconfig)
+ - Avnet ZedBoard (zynq_zed_defconfig)
+ - Avnet MicroZed (zynq_microzed_defconfig)
+
+The following build procedure focuses on them, but you can adjust it to your
+board even if it is not listed above.  Major Zynq-based boards are supported by
+U-Boot, and their Device Trees are merged in Linux Kernel.  If your board is the
+case, booting the kernel is a piece of cake.  All you need to do is to change:
+ - Kernel Device Tree file name (BR2_LINUX_KERNEL_INTREE_DTS_NAME)
+ - U-Boot board defconfig (BR2_TARGET_UBOOT_BOARDNAME)
+
+Steps to create a working system for a Zynq board:
+
+1) Configuration (do one of the followings)
+    make zynq_zc706_defconfig     (ZC706)
+    make zynq_zed_defconfig       (Zedboard)
+    make zynq_microzed_defconfig  (MicroZed)
+2) make
+3) All needed files will be available in the output/images directory.
+   Create a FAT32 partition at the beginning of your SD Card and copy files:
+     - boot.bin
+     - u-boot.img
+     - uImage
+     - uramdisk.image.gz (should be renamed from rootfs.cpio.uboot)
+     - devicetree.dtb (should be renamed from zynq-***.dtb)
+   into your SD card
+4) boot your board
+
+You can alter the booting procedure by creating a file uEnv.txt
+in the root of the SD card. It is a plain text file in format
+<key>=<value> one per line:
+
+kernel_image=myimage
+modeboot=myboot
+myboot=...
+
+Note:
+The DTB for MicroZed is the same as the one for the Zedboard (zynq-zed.dtb),
+and this is the recommended solution, see
+https://forums.xilinx.com/t5/Embedded-Linux/Microzed-default-device-tree-dts/td-p/432856.
+
+References:
+ - ZC706 information including schematics, reference designs, and manuals are
+   available from
+   http://www.xilinx.com/products/boards-and-kits/ek-z7-zc706-g.html.
+
+ - Zedboard/Microzed information including schematics, reference designs, and
+   manuals are available from http://www.zedboard.org .