[U-Boot] [PATCH v3 25/25] rockchip: Add a simple README

Naoki FUKAUMI
2015-06-24T04:24:46Z

Hi,

On Wed, Jun 24, 2015 at 8:29 AM, Simon Glass <sjg@chromium.org> wrote:
> Add a few notes on how to try out the Rockchip support so far.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
> Changes in v3:
> - Update README to mention available drivers
> - Add various new patches to get RK3288 booting to a prompt
>
> Changes in v2: None
>
> doc/README.rockchip | 246 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 246 insertions(+)
> create mode 100644 doc/README.rockchip
>
> diff --git a/doc/README.rockchip b/doc/README.rockchip
> new file mode 100644
> index 0000000..a34e198
> --- /dev/null
> +++ b/doc/README.rockchip
> @@ -0,0 +1,246 @@
> +#
> +# 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.
> +
> +So far only support for the RK3288 is provided.
> +
> +
> +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 three RK3288 boards are supported:
> +
> + - Firefly RK3288 - use firefly-rk3288 configuration
> + - Radxa Rock Pro - also uses firefly-rk3288 configuration
> + - Haier Chromebook - use chromebook_jerry configuration
> +
> +For example:
> +
> + CROSS_COMPILE=arm-linux-gnueabi- make O=firefly firefly-rk3288_defconfig all
> +
> +(or you can use another cross compiler if you prefer)
> +
> +Note that the Radxa Rock Pro uses the Firefly configuration for now as
> +device tree files are not yet available for the Rock Pro. Clearly the two
> +have hardware differences, so this approach will break down as more drivers
> +are added.
> +
> +
> +Writing to the board with USB
> +=============================
> +
> +For USB 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.

"holding the recovery" method will load & run loader from flash
storage (if available). if my memory is correct, SPL cannot be loaded
in this case. (rkflashtool l doesn't work)

if working (Rockchip's) loader is already loaded, "rkflashtool b 3"
might work to enter mask rom mode.
https://github.com/linux-rockchip/rkflashtool/commit/f6159af25af766374e1d8a2cb2901d522102b8b8

I'll check it later.

> +To erase your MMC, you can boot into Linux and type (as root)
> +
> + dd if=/dev/zero of=/dev/mmcblk0 bs=1M
> +
> +Connect your board's OTG port to your computer.
> +
> +To create a suitable image and write it to the board:
> +
> + ./firefly-rk3288/tools/mkimage -T rkimage -d ./firefly-rk3288/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 2015.07-rc1-00383-ge345740-dirty (Jun 03 2015 - 10:06:49)
> + Card did not respond to voltage select!
> + spl: mmc init failed with error: -17
> + ### 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. If support for the Rockchip USB protocol or DFU were added
> +in SPL then we could in principle load U-Boot and boot to a prompt from USB
> +as several other platforms do. However it does not seem to be possible to
> +use the existing boot ROM code from SPL.
> +
> +
> +Booting from an SD card
> +=======================
> +
> +To write an image that boots from an SD card (assumed to be /dev/sdc):
> +
> + ./firefly-rk3288/tools/mkimage -T rksd -d firefly-rk3288/spl/u-boot-spl-dtb.bin out
> + sudo dd if=out of=/dev/sdc
> + sudo dd if=firefly-rk3288/u-boot-dtb.img of=/dev/sdc seek=256
> +
> +This puts the Rockchip header and SPL image first and then places the U-Boot
> +image at block 256 (i.e. 128KB from the start of the SD card). This
> +corresponds with this setting in U-Boot:
> +
> + #define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 256
> +
> +Put this SD (or micro-SD) card into your board and reset it. You should see
> +something like:
> +
> + U-Boot SPL 2015.07-rc1-00383-ge345740-dirty (Jun 03 2015 - 11:04:40)
> +
> +
> + U-Boot 2015.07-rc1-00383-ge345740-dirty (Jun 03 2015 - 11:04:40)
> +
> + DRAM: 2 GiB
> + MMC:
> + Using default environment
> +
> + In: serial at ff690000
> + Out: serial at ff690000
> + Err: serial at ff690000
> + =>
> +
> +
> +Booting from SPI
> +================
> +
> +To write an image that boots from SPI flash (e.g. for the Haier Chromebook):
> +
> + ./chromebook_jerry/tools/mkimage -T rkspi -d chromebook_jerry/spl/u-boot-spl-dtb.bin out
> + dd if=spl.bin of=out.bin bs=128K conv=sync
> + cat chromebook_jerry/u-boot-dtb.img out.bin
> + dd if=out.bin of=out.bin.pad bs=4M conv=sync
> +
> +This converts the SPL image to the required SPI format by adding the Rockchip
> +header and skipping every 2KB block. Then the U-Boot image is written at
> +offset 128KB and the whole image is padded to 4MB which is the SPI flash size.
> +The position of U-Boot is controlled with this setting in U-Boot:
> +
> + #define CONFIG_SYS_SPI_U_BOOT_OFFS (128 << 10)
> +
> +If you have a Dediprog em100pro connected then you can write the image with:
> +
> + sudo em100 -s -c GD25LQ32 -d out.bin.pad -r
> +
> +When booting you should see something like:
> +
> + U-Boot SPL 2015.07-rc2-00215-g9a58220-dirty (Jun 23 2015 - 12:11:32)
> +
> +
> + U-Boot 2015.07-rc2-00215-g9a58220-dirty (Jun 23 2015 - 12:11:32 -0600)
> +
> + Model: Google Jerry
> + DRAM: 2 GiB
> + MMC:
> + Using default environment
> +
> + In: serial at ff690000
> + Out: serial at ff690000
> + Err: serial at ff690000
> + =>
> +
> +
> +Future work
> +===========
> +
> +Immediate priorities are:
> +
> +- MMC support (in U-Boot itself)
> +- GPIO (driver exists but is lightly tested)
> +- I2C (driver exists but is non-functional)
> +- USB host
> +- USB device
> +- PMIC and regulators (only ACT8846 is supported at present)
> +- LCD and HDMI
> +- Run CPU at full speed
> +- Ethernet
> +- NAND flash
> +- Support for other Rockchip parts
> +- Boot U-Boot proper over USB OTG (at present only SPL works)
> +
> +
> +Development Notes
> +=================
> +
> +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
> +
> +rkimage
> +-------
> +
> +rkimage.c produces an SPL image suitable for sending directly to the boot ROM
> +over USB OTG. This is a very simple format - just the string RK32 (as 4 bytes)
> +followed by u-boot-spl-dtb.bin.
> +
> +The boot ROM loads image to 0xff704000 which is in the internal SRAM. The SRAM
> +starts at 0xff700000 and extends to 0xff718000 where we put the stack.
> +
> +rksd
> +----
> +
> +rksd.c produces an image consisting of 32KB of empty space, a header and
> +u-boot-spl-dtb.bin. The header is defined by 'struct header0_info' although
> +most of the fields are unused by U-Boot. We just need to specify the
> +signature, a flag and the block offset and size of the SPL image.
> +
> +The header occupies a single block but we pad it out to 4 blocks. The header
> +is encoding using RC4 with the key 7c4e0304550509072d2c7b38170d1711. The SPL
> +image can be encoded too but we don't do that.
> +
> +The maximum size of u-boot-spl-dtb.bin which the boot ROM will read is 32KB,
> +or 0x40 blocks. This is a severe and annoying limitation. There may be a way
> +around this limitation, since there is plenty of SRAM, but at present the
> +board refuses to boot if this limit is exceeded.
> +
> +The image produced is padded up to a block boundary (512 bytes). It should be
> +written to the start of an SD card using dd.
> +
> +Since this image is set to load U-Boot from the SD card at block offset,
> +CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, dd should be used to write
> +u-boot-dtb.img to the SD card at that offset. See above for instructions.
> +
> +rkspi
> +-----
> +
> +rkspi.c produces an image consisting of a header and u-boot-spl-dtb.bin. The
> +resulting image is then spread out so that only the first 2KB of each 4KB
> +sector is used. The header is the same as with rksd and the maximum size is
> +also 32KB (before spreading). The image should be written to the start of
> +SPI flash.
> +
> +See above for instructions on how to write a SPI image.
> +
> +
> +Device tree and driver model
> +----------------------------
> +
> +Where possible driver model is used to provide a structure to the
> +functionality. Device tree is used for configuration. However these have an
> +overhead and in SPL with a 32KB size limit some shortcuts have been taken.
> +In general all Rockchip drivers should use these features, with SPL-specific
> +modifications where required.
> +
> +
> +--
> +Simon Glass <sjg@chromium.org>
> +24 June 2015
> --
> 2.4.3.573.g4eafbef
>