Add a few notes on how to try out the Rockchip support so far.
Signed-off-by: Simon Glass sjg@chromium.org ---
doc/README.rockchip | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 doc/README.rockchip
diff --git a/doc/README.rockchip b/doc/README.rockchip new file mode 100644 index 0000000..2f26814 --- /dev/null +++ b/doc/README.rockchip @@ -0,0 +1,83 @@ +# +# Copyright (C) 2015 Google. Inc +# Written by Simon Glass sjg@chromium.org +# +# SPDX-License-Identifier: GPL-2.0+ +# + +U-Boot on Rockchip +================== + +There are several repositories available with versions of U-Boot that support +many Rockchip devices [1] [2]. + +The current mainline support is experimental only and is not useful for +anything. It should provide a base on which to build. + + +Prerequisites +============= + +You will need: + + - Firefly RK3288 baord + - Power connection to 5V using the supplied micro-USB power cable + - Separate USB serial cable attached to your computer and the Firefly + (connect to the micro-USB connector below the logo) + - rkflashtool [3] + - openssl (sudo apt-get install openssl) + - Serial UART connection [4] + - Suitable ARM cross compiler, e.g.: + sudo apt-get install gcc-4.7-arm-linux-gnueabi + + +Building +======== + +At present, only Firefly RK3288 is supported. You can use the firefly-rk3288 +configuration for this. + + CROSS_COMPILE=arm-linux-gnueabi- make O=firefly firefly-rk3288_defconfig all + +(or you can use another cross compiler if you prefer) + + +Writing to the board +==================== + +Only USB is supported. For this to work you must get your board into ROM +boot mode, either by erasing your MMC or (perhaps) holding the recovery +button when you boot the board. To erase your MMC, you can boot into Linux +and type (as root) 'dd if=/dev/zero of=/dev/mmcblk0 bs=1M'. + +To create a suitable image and write it to the board: + + ./firefly/tools/mkimage -T rockchip -d firefly/spl/u-boot-spl-dtb.bin out + cat out | openssl rc4 -K 7c4e0304550509072d2c7b38170d1711 | rkflashtool l + +If all goes well you should something like: + + U-Boot SPL 2015.04-rc2-00123-gc5b539a-dirty (Feb 27 2015 - 09:35:31) + SPL: Unsupported Boot Device! + ### ERROR ### Please RESET the board ### + +You will need to reset the board before each time you try. Yes, that's all +it does so far. + + +Future work +=========== + +Immediate priorities are: + +- Support SPL clock init +- Support loading U-Boot from MMC +- Boot U-Boot to a prompt + +There are plenty of patches in the links below to help with this work. + + +[1] https://github.com/rkchrome/uboot.git +[2] https://github.com/linux-rockchip/u-boot-rockchip.git branch u-boot-rk3288 +[3] https://github.com/linux-rockchip/rkflashtool.git +[4] http://wiki.t-firefly.com/index.php/Firefly-RK3288/Serial_debug/en