[U-Boot] [PATCH v6 3/3] Odroid-XU3: Add documentation for Odroid-XU3

[Hyungwon Hwang]

This patch adds documentation for Odroid-XU3. This documentation is
based on that of Odroid (doc/README-odroid) made by Przemyslaw Marczak.
The documentation includes basic information about boot media layout,
environment, partition layout, and the instruction to burn the u-boot
image to boot media.

Signed-off-by: Hyungwon Hwang <human.hwang at samsung.com>
Cc: Minkyu Kang <mk7.kang at samsung.com>
Cc: Lukasz Majewski <l.majewski at samsung.com>
---
Changes for v6:
- Newly added

 doc/README.odroid-xu3 | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 doc/README.odroid-xu3

diff --git a/doc/README.odroid-xu3 b/doc/README.odroid-xu3
new file mode 100644
index 0000000..8e1f333
--- /dev/null
+++ b/doc/README.odroid-xu3
@@ -0,0 +1,134 @@
+ U-boot for Odroid XU3
+========================
+
+1. Summary
+==========
+This is a quick instruction for setup Odroid boards based on Exynos5422.
+Exynos5422 is almost same with Exynos5800 which is a variant of Exynos5422 for
+Chromebook.
+
+Board config: odroid-xu3_config
+
+2. Supported devices
+====================
+This U-BOOT config can be used on the board:
+- Odroid XU3
+with CPU Exynos 5422 and 2GB of RAM
+
+3. Boot sequence
+================
+iROM->BL1->(BL2 + TrustZone)->U-BOOT
+
+To boot up, this version of U-BOOT needs BL1, BL2, and TrustZone binary.
+It can be downloaded from:
+https://github.com/hardkernel/u-boot/tree/odroidxu3-v2012.07/sd_fuse/hardkernel
+
+4. Boot media layout
+====================
+The table below shows SD/eMMC cards layout for U-boot.
+The block offset is starting from 0 and the block size is 512B.
+ -------------------------------------
+|  Binary   | Block offset| part type |
+|   name    | SD   | eMMC |(eMMC only)|
+ -------------------------------------
+| Bl1       | 1    | 0    |  1 (boot) |
+| Bl2       | 31   | 30   |  1 (boot) |
+| U-boot    | 63   | 62   |  1 (boot) |
+| Tzsw      | 2111 | 2110 |  1 (boot) |
+| Uboot Env | 2500 | 2500 |  0 (user) |
+ -------------------------------------
+
+5. Prepare the SD boot card - with SD card reader
+=================================================
+To prepare bootable media you need boot binaries provided by hardkernel.
+The files from the link in point 3.
+- bl1.bin.hardkernel
+- bl2.bin.hardkernel
+- tzsw.bin.hardkernel
+- u-boot.bin.hardkernel
+
+This is all you need to boot this board. You can write the binaries to SD card
+just by executiog sd_fusing.sh. You cannot use this script to write binaries to
+eMMC card.It is valid only for SD card.
+
+*note
+You cannot access the eMMC protected part (the first 8MB roughly) using an
+ordinary eMMC reader.
+
+*note:
+If you build u-boot by yourself, you will find u-boot.bin and u-boot-dtb.bin
+as the build result. You have to use u-boot-dtb.bin instead of u-boot.bin.
+
+quick steps for Linux:
+- Download all files from the link at point 3.
+- put any SD card into the SD reader
+- check the device with "dmesg"
+- run ./sd_fusing.sh /dev/sdX - where X is SD card device (but not a partition)
+Check if Hardkernel U-boot is booting, and next do the same with your U-boot.
+
+6. Prepare the eMMC boot card
+   with a eMMC card reader (boot from eMMC card slot)
+=====================================================
+To boot the device from the eMMC slot you should use a special card reader
+which supports eMMC partition switch. All of the boot binaries are stored
+on the eMMC boot partition which is normally hidden.
+
+The "sd_fusing.sh" script can be used after updating offsets of binaries
+according to the table from point 4. Be sure that you are working on the right
+eMMC partition - its size is usually very small, about 1-4 MiB.
+
+7. Prepare the eMMC boot card
+   with a SD card reader (boot from SD card slot)
+=================================================
+If you have an eMMC->microSD adapter you can prepare the card as in point 5.
+But then the device can boot only from the SD card slot.
+
+8. Prepare the boot media using Hardkernel U-boot
+=================================================
+You can update the U-boot to the custom one if you have an working bootloader
+delivered with the board on a eMMC/SD card. Then follow the steps:
+- install the android fastboot tool
+- connect a micro usb cable to the board
+- on the U-boot prompt, run command: fastboot (as a root)
+- on the host, run command: "fastboot flash bootloader u-boot-dtb.bin"
+- the custom U-boot should start after the board resets.
+
+9. Partition layout
+====================
+Default U-boot environment is setup for fixed partition layout.
+
+Partition table: MSDOS. Disk layout and files as listed in the table below.
+ ----- ------ ------ ------ -------- ---------------------------------
+| Num | Name |  FS  | Size | Offset |         Reguired files          |
+|     |      | Type |  MiB |  MiB   |                                 |
+ ----- ------ ------ ------ -------- ---------------------------------
+|  1  | BOOT | fat  |  100 |   2    |  kernel, fdt**                  |
+|  2  | ROOT | ext4 |   -  |        |  any Linux system               |
+ ----- ------ ------ ------ -------- ---------------------------------
+
+**note:
+Supported fdt files are:
+- exynos5422-odroidxu3.dtb
+
+Supported kernel files are:
+- Image.itb
+- zImage
+- uImage
+
+10. The environment and booting the kernel
+==========================================
+There are three macros defined in config for various boot options:
+Two for both, kernel with device tree support and also without it:
+- boot_uimg - load uImage
+- boot_zimg - load zImage
+If proper fdt file exists then it will be automatically loaded,
+so for old kernel types, please remove fdt file from boot partition.
+
+The third boot option for multi image support (more info: doc/uImage.FIT/)
+- boot_fit - for binary file: "Image.itb"
+
+Default boot command: "autoboot"
+And the boot sequence is:
+- boot_fit - if "Image.itb" exists
+- boot_zimg - if "zImage" exists
+- boot_uimg - if "uImage" exists
-- 
1.8.3.2