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

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

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@ff690000
> +   Out:   serial@ff690000
> +   Err:   serial@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@ff690000
> +   Out:   serial@ff690000
> +   Err:   serial@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
>

Hi Simon,

On 24/06/15 00:29, Simon Glass wrote:
> diff --git a/doc/README.rockchip b/doc/README.rockchip
> new file mode 100644
> index 0000000..a34e198
> --- /dev/null
> +++ b/doc/README.rockchip

....

> +
> +Future work
> +===========
> +
> +Immediate priorities are:
> +
> +- MMC support (in U-Boot itself)

Can you briefly sketch what is missing here? If I got this correctly,
the SPL part has MMC working, right?
If that works, we should be able to load a kernel from the SD card,
shouldn't we?

Cheers,
Andre.

P.S. Is there any news on the oversized SPL image? I disabled LED
support in the SPL for the time being, so the resulting image is 32189
Bytes (vanilla GCC 5.1.0) and it works for me now.


> +- 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
>

Hi Andre,

On 27 July 2015 at 11:08, Andre Przywara <andre.przywara@arm.com> wrote:
>
> Hi Simon,
>
> On 24/06/15 00:29, Simon Glass wrote:
> > diff --git a/doc/README.rockchip b/doc/README.rockchip
> > new file mode 100644
> > index 0000000..a34e198
> > --- /dev/null
> > +++ b/doc/README.rockchip
>
> ....
>
> > +
> > +Future work
> > +===========
> > +
> > +Immediate priorities are:
> > +
> > +- MMC support (in U-Boot itself)
>
> Can you briefly sketch what is missing here? If I got this correctly,
> the SPL part has MMC working, right?
> If that works, we should be able to load a kernel from the SD card,
> shouldn't we?

Yes but it is untested. I suspect there will be a few issues but it
should not be hard to figure out.

>
> Cheers,
> Andre.
>
> P.S. Is there any news on the oversized SPL image? I disabled LED
> support in the SPL for the time being, so the resulting image is 32189
> Bytes (vanilla GCC 5.1.0) and it works for me now.

Does that GCC have the bug fix?

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54303
https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00509.html

It will be a few weeks before I get back to this sorry.

Regards,
Simon

>
>
> > +- 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
> >

Hi Simon

On Tue, 2015-06-23 at 17:29 -0600, Simon Glass wrote:
> +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)

Is it always necessary for RK3288 to have full PMIC support? Wouldn't it
be possible in most cases to go with the reset-default-values (of a
let's say ACT8846) to boot Linux from an SD-Card?

Thanks
  -- Christoph

Hi Christoph,

On 6 August 2015 at 09:35, Christoph Fritz <chf.fritz@googlemail.com> wrote:
> Hi Simon
>
> On Tue, 2015-06-23 at 17:29 -0600, Simon Glass wrote:
>> +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)
>
> Is it always necessary for RK3288 to have full PMIC support? Wouldn't it
> be possible in most cases to go with the reset-default-values (of a
> let's say ACT8846) to boot Linux from an SD-Card?

For U-Boot to start and boot at full speed it is often necessary ti
increase the voltage on various rails. Some peripherals may require
regulators to be enabled. It depends on your requirements.

Regards,
Simon