2 # Copyright (C) 2015 Google. Inc
3 # Written by Simon Glass <sjg@chromium.org>
5 # SPDX-License-Identifier: GPL-2.0+
11 There are several repositories available with versions of U-Boot that support
12 many Rockchip devices [1] [2].
14 The current mainline support is experimental only and is not useful for
15 anything. It should provide a base on which to build.
17 So far only support for the RK3288 and RK3036 is provided.
25 - Firefly RK3288 board or something else with a supported RockChip SoC
26 - Power connection to 5V using the supplied micro-USB power cable
27 - Separate USB serial cable attached to your computer and the Firefly
28 (connect to the micro-USB connector below the logo)
30 - openssl (sudo apt-get install openssl)
31 - Serial UART connection [4]
32 - Suitable ARM cross compiler, e.g.:
33 sudo apt-get install gcc-4.7-arm-linux-gnueabi
39 At present five RK3288 boards are supported:
41 - Firefly RK3288 - use firefly-rk3288 configuration
42 - Radxa Rock 2 - use rock2 configuration
43 - Hisense Chromebook - use chromebook_jerry configuration
44 - EVB RK3288 - use evb-rk3288 configuration
45 - Fennec RK3288 - use fennec-rk3288 configuration
47 Two RK3036 board are supported:
49 - EVB RK3036 - use evb-rk3036 configuration
50 - Kylin - use kylin_rk3036 configuration
54 CROSS_COMPILE=arm-linux-gnueabi- make O=firefly firefly-rk3288_defconfig all
56 (or you can use another cross compiler if you prefer)
59 Writing to the board with USB
60 =============================
62 For USB to work you must get your board into ROM boot mode, either by erasing
63 your MMC or (perhaps) holding the recovery button when you boot the board.
64 To erase your MMC, you can boot into Linux and type (as root)
66 dd if=/dev/zero of=/dev/mmcblk0 bs=1M
68 Connect your board's OTG port to your computer.
70 To create a suitable image and write it to the board:
72 ./firefly-rk3288/tools/mkimage -n rk3288 -T rkimage -d \
73 ./firefly-rk3288/spl/u-boot-spl-dtb.bin out && \
74 cat out | openssl rc4 -K 7c4e0304550509072d2c7b38170d1711 | rkflashtool l
76 If all goes well you should something like:
78 U-Boot SPL 2015.07-rc1-00383-ge345740-dirty (Jun 03 2015 - 10:06:49)
79 Card did not respond to voltage select!
80 spl: mmc init failed with error: -17
81 ### ERROR ### Please RESET the board ###
83 You will need to reset the board before each time you try. Yes, that's all
84 it does so far. If support for the Rockchip USB protocol or DFU were added
85 in SPL then we could in principle load U-Boot and boot to a prompt from USB
86 as several other platforms do. However it does not seem to be possible to
87 use the existing boot ROM code from SPL.
90 Booting from an SD card
91 =======================
93 To write an image that boots from an SD card (assumed to be /dev/sdc):
95 ./firefly-rk3288/tools/mkimage -n rk3288 -T rksd -d \
96 firefly-rk3288/spl/u-boot-spl-dtb.bin out && \
97 sudo dd if=out of=/dev/sdc seek=64 && \
98 sudo dd if=firefly-rk3288/u-boot-dtb.img of=/dev/sdc seek=256
100 This puts the Rockchip header and SPL image first and then places the U-Boot
101 image at block 256 (i.e. 128KB from the start of the SD card). This
102 corresponds with this setting in U-Boot:
104 #define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 256
106 Put this SD (or micro-SD) card into your board and reset it. You should see
109 U-Boot 2016.01-rc2-00309-ge5bad3b-dirty (Jan 02 2016 - 23:41:59 -0700)
111 Model: Radxa Rock 2 Square
113 MMC: dwmmc@ff0f0000: 0, dwmmc@ff0c0000: 1
114 *** Warning - bad CRC, using default environment
117 Out: vop@ff940000.vidconsole
119 Net: Net Initialization Skipped
121 Hit any key to stop autoboot: 0
124 The rockchip bootrom can load and boot an initial spl, then continue to
125 load a second-level bootloader(ie. U-BOOT) as soon as it returns to bootrom.
126 Therefore RK3288 has another loading sequence like RK3036. The option of
127 U-Boot is controlled with this setting in U-Boot:
129 #define CONFIG_ROCKCHIP_SPL_BACK_TO_BROM
131 You can create the image via the following operations:
133 ./firefly-rk3288/tools/mkimage -n rk3288 -T rksd -d \
134 firefly-rk3288/spl/u-boot-spl-dtb.bin out && \
135 cat firefly-rk3288/u-boot-dtb.bin >> out && \
136 sudo dd if=out of=/dev/sdc seek=64
138 If you have an HDMI cable attached you should see a video console.
140 For evb_rk3036 board:
141 ./evb-rk3036/tools/mkimage -n rk3036 -T rksd -d evb-rk3036/spl/u-boot-spl.bin out && \
142 cat evb-rk3036/u-boot-dtb.bin >> out && \
143 sudo dd if=out of=/dev/sdc seek=64
145 Note: rk3036 SDMMC and debug uart use the same iomux, so if you boot from SD, the
146 debug uart must be disabled
148 Using fastboot on rk3288
149 ========================
150 - Define GPT partition layout like kylin_rk3036(see include/configs/kylin_rk3036.h)
151 - Write GPT partition layout to mmc device which fastboot want to use it to
154 => gpt write mmc 1 $partitions
156 - Invoke fastboot command to prepare
160 - Start fastboot request on PC
162 fastboot -i 0x2207 flash loader evb-rk3288/spl/u-boot-spl-dtb.bin
164 You should see something like:
167 WARNING: unknown variable: partition-type:loader
168 Starting download of 357796 bytes
170 downloading of 357796 bytes finished
172 ........ wrote 357888 bytes to 'loader'
177 To write an image that boots from SPI flash (e.g. for the Haier Chromebook):
179 ./chromebook_jerry/tools/mkimage -n rk3288 -T rkspi \
180 -d chromebook_jerry/spl/u-boot-spl-dtb.bin spl.bin && \
181 dd if=spl.bin of=spl-out.bin bs=128K conv=sync && \
182 cat spl-out.bin chromebook_jerry/u-boot-dtb.img >out.bin && \
183 dd if=out.bin of=out.bin.pad bs=4M conv=sync
185 This converts the SPL image to the required SPI format by adding the Rockchip
186 header and skipping every 2KB block. Then the U-Boot image is written at
187 offset 128KB and the whole image is padded to 4MB which is the SPI flash size.
188 The position of U-Boot is controlled with this setting in U-Boot:
190 #define CONFIG_SYS_SPI_U_BOOT_OFFS (128 << 10)
192 If you have a Dediprog em100pro connected then you can write the image with:
194 sudo em100 -s -c GD25LQ32 -d out.bin.pad -r
196 When booting you should see something like:
198 U-Boot SPL 2015.07-rc2-00215-g9a58220-dirty (Jun 23 2015 - 12:11:32)
201 U-Boot 2015.07-rc2-00215-g9a58220-dirty (Jun 23 2015 - 12:11:32 -0600)
206 Using default environment
217 Immediate priorities are:
221 - Run CPU at full speed (code exists but we only see ~60 DMIPS maximum)
224 - Support for other Rockchip parts
225 - Boot U-Boot proper over USB OTG (at present only SPL works)
231 There are plenty of patches in the links below to help with this work.
233 [1] https://github.com/rkchrome/uboot.git
234 [2] https://github.com/linux-rockchip/u-boot-rockchip.git branch u-boot-rk3288
235 [3] https://github.com/linux-rockchip/rkflashtool.git
236 [4] http://wiki.t-firefly.com/index.php/Firefly-RK3288/Serial_debug/en
241 rkimage.c produces an SPL image suitable for sending directly to the boot ROM
242 over USB OTG. This is a very simple format - just the string RK32 (as 4 bytes)
243 followed by u-boot-spl-dtb.bin.
245 The boot ROM loads image to 0xff704000 which is in the internal SRAM. The SRAM
246 starts at 0xff700000 and extends to 0xff718000 where we put the stack.
251 rksd.c produces an image consisting of 32KB of empty space, a header and
252 u-boot-spl-dtb.bin. The header is defined by 'struct header0_info' although
253 most of the fields are unused by U-Boot. We just need to specify the
254 signature, a flag and the block offset and size of the SPL image.
256 The header occupies a single block but we pad it out to 4 blocks. The header
257 is encoding using RC4 with the key 7c4e0304550509072d2c7b38170d1711. The SPL
258 image can be encoded too but we don't do that.
260 The maximum size of u-boot-spl-dtb.bin which the boot ROM will read is 32KB,
261 or 0x40 blocks. This is a severe and annoying limitation. There may be a way
262 around this limitation, since there is plenty of SRAM, but at present the
263 board refuses to boot if this limit is exceeded.
265 The image produced is padded up to a block boundary (512 bytes). It should be
266 written to the start of an SD card using dd.
268 Since this image is set to load U-Boot from the SD card at block offset,
269 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, dd should be used to write
270 u-boot-dtb.img to the SD card at that offset. See above for instructions.
275 rkspi.c produces an image consisting of a header and u-boot-spl-dtb.bin. The
276 resulting image is then spread out so that only the first 2KB of each 4KB
277 sector is used. The header is the same as with rksd and the maximum size is
278 also 32KB (before spreading). The image should be written to the start of
281 See above for instructions on how to write a SPI image.
286 You can use this script to create #defines for SoC register access. See the
290 Device tree and driver model
291 ----------------------------
293 Where possible driver model is used to provide a structure to the
294 functionality. Device tree is used for configuration. However these have an
295 overhead and in SPL with a 32KB size limit some shortcuts have been taken.
296 In general all Rockchip drivers should use these features, with SPL-specific
297 modifications where required.
301 Simon Glass <sjg@chromium.org>