1# SPDX-License-Identifier: GPL-2.0+
2#
3# Copyright (C) 2015 Google. Inc
4# Written by Simon Glass <sjg@chromium.org>
5
6U-Boot on Rockchip
7==================
8
9A wide range of Rockchip SoCs are supported in mainline U-Boot
10
11Warning
12=======
13This document is being moved to doc/board/rockchip, so information on it
14might be incomplete or outdated.
15
16Prerequisites
17=============
18
19You will need:
20
21   - Firefly RK3288 board or something else with a supported RockChip SoC
22   - Power connection to 5V using the supplied micro-USB power cable
23   - Separate USB serial cable attached to your computer and the Firefly
24        (connect to the micro-USB connector below the logo)
25   - rkflashtool [3]
26   - openssl (sudo apt-get install openssl)
27   - Serial UART connection [4]
28   - Suitable ARM cross compiler, e.g.:
29        sudo apt-get install gcc-4.7-arm-linux-gnueabi
30
31Building
32========
33
341. To build RK3288 board:
35
36   CROSS_COMPILE=arm-linux-gnueabi- make O=firefly firefly-rk3288_defconfig all
37
38    (or you can use another cross compiler if you prefer)
39
402. To build RK3308 board:
41   - Get the rkbin
42     => git clone https://github.com/rockchip-linux/rkbin.git
43
44   - Compile U-Boot
45     => cd /path/to/u-boot
46     => export BL31=/path/to/rkbin/bin/rk33/rk3308_bl31_v2.22.elf
47     => make roc-cc-rk3308_defconfig
48     => make CROSS_COMPILE=aarch64-linux-gnu- all
49     => ./tools/mkimage -n rk3308 -T rksd -d /path/to/rkbin/bin/rk33/rk3308_ddr_589MHz_uart2_m0_v1.26.bin idbloader.img
50     => cat spl/u-boot-spl.bin  >> idbloader.img
51
523. To build RK3399 board:
53
54   Option 1: Package the image with Rockchip miniloader:
55
56   - Compile U-Boot
57
58     => cd /path/to/u-boot
59     => make nanopi-neo4-rk3399_defconfig
60     => make
61
62   - Get the rkbin
63
64     => git clone https://github.com/rockchip-linux/rkbin.git
65
66   - Create trust.img
67
68     => cd /path/to/rkbin
69     => ./tools/trust_merger RKTRUST/RK3399TRUST.ini
70
71   - Create uboot.img
72
73     => cd /path/to/rkbin
74     => ./tools/loaderimage --pack --uboot /path/to/u-boot/u-boot-dtb.bin uboot.img
75
76     (Get trust.img and uboot.img)
77
78   Option 2: Package the image with SPL:
79
80   - Export cross compiler path for aarch64
81
82   - Compile ATF
83
84     For Puma board.
85
86	=> git clone git://git.theobroma-systems.com/arm-trusted-firmware.git
87	=> cd arm-trusted-firmware
88	=> make CROSS_COMPILE=aarch64-linux-gnu- PLAT=rk3399 bl31
89
90	(export bl31.bin)
91	=> export BL31=/path/to/arm-trusted-firmware/build/rk3399/release/bl31/bl31.bin
92
93     For rest of rk3399 boards.
94
95	=> git clone https://github.com/ARM-software/arm-trusted-firmware.git
96	=> cd arm-trusted-firmware
97
98	(export cross compiler path for Cortex-M0 MCU likely arm-none-eabi-)
99	=> make realclean
100	=> make CROSS_COMPILE=aarch64-linux-gnu- PLAT=rk3399
101
102	(export bl31.elf)
103	=> export BL31=/path/to/arm-trusted-firmware/build/rk3399/release/bl31/bl31.elf
104
105   - Compile PMU M0 firmware
106
107     This is optional for most of the rk3399 boards and required only for Puma board.
108
109     => git clone git://git.theobroma-systems.com/rk3399-cortex-m0.git
110     => cd rk3399-cortex-m0
111
112     (export cross compiler path for Cortex-M0 PMU)
113     => make CROSS_COMPILE=arm-cortex_m0-eabi-
114
115     (export rk3399m0.bin)
116     => export PMUM0=/path/to/rk3399-cortex-m0/rk3399m0.bin
117
118   - Compile U-Boot
119
120     => cd /path/to/u-boot
121     => make orangepi-rk3399_defconfig
122     => make
123
124     (Get spl/u-boot-spl-dtb.bin, u-boot.itb images and some boards would get
125      spl/u-boot-spl.bin since it doesn't enable CONFIG_SPL_OF_CONTROL
126
127      If TPL enabled on the target, get tpl/u-boot-tpl-dtb.bin or tpl/u-boot-tpl.bin
128      if CONFIG_TPL_OF_CONTROL not enabled)
129
130Writing to the board with USB
131=============================
132
133For USB to work you must get your board into ROM boot mode, either by erasing
134your MMC or (perhaps) holding the recovery button when you boot the board.
135To erase your MMC, you can boot into Linux and type (as root)
136
137   dd if=/dev/zero of=/dev/mmcblk0 bs=1M
138
139Connect your board's OTG port to your computer.
140
141To create a suitable image and write it to the board:
142
143   ./firefly-rk3288/tools/mkimage -n rk3288 -T rkimage -d \
144	./firefly-rk3288/spl/u-boot-spl-dtb.bin out && \
145   cat out | openssl rc4 -K 7c4e0304550509072d2c7b38170d1711 | rkflashtool l
146
147If all goes well you should something like:
148
149   U-Boot SPL 2015.07-rc1-00383-ge345740-dirty (Jun 03 2015 - 10:06:49)
150   Card did not respond to voltage select!
151   spl: mmc init failed with error: -17
152   ### ERROR ### Please RESET the board ###
153
154You will need to reset the board before each time you try. Yes, that's all
155it does so far. If support for the Rockchip USB protocol or DFU were added
156in SPL then we could in principle load U-Boot and boot to a prompt from USB
157as several other platforms do. However it does not seem to be possible to
158use the existing boot ROM code from SPL.
159
160
161Writing to the eMMC with USB on ROC-RK3308-CC
162=============================================
163For USB to work you must get your board into Bootrom mode,
164either by erasing the eMMC or short circuit the GND and D0
165on core board.
166
167Connect the board to your computer via tyepc.
168=> rkdeveloptool db rk3308_loader_v1.26.117.bin
169=> rkdeveloptool wl 0x40 idbloader.img
170=> rkdeveloptool wl 0x4000 u-boot.itb
171=> rkdeveloptool rd
172
173Then you will see the boot log from Debug UART at baud rate 1500000:
174DDR Version V1.26
175REGFB: 0x00000032, 0x00000032
176In
177589MHz
178DDR3
179 Col=10 Bank=8 Row=14 Size=256MB
180msch:1
181Returning to boot ROM...
182
183U-Boot SPL 2020.01-rc1-00225-g34b681327f (Nov 14 2019 - 10:58:04 +0800)
184Trying to boot from MMC1
185INFO:    Preloader serial: 2
186NOTICE:  BL31: v1.3(release):30f1405
187NOTICE:  BL31: Built : 17:08:28, Sep 23 2019
188INFO:    Lastlog: last=0x100000, realtime=0x102000, size=0x2000
189INFO:    ARM GICv2 driver initialized
190INFO:    Using opteed sec cpu_context!
191INFO:    boot cpu mask: 1
192INFO:    plat_rockchip_pmu_init: pd status 0xe b
193INFO:    BL31: Initializing runtime services
194WARNING: No OPTEE provided by BL2 boot loader, Booting device without OPTEE initialization. SMC`s destined for OPTEE will rK
195ERROR:   Error initializing runtime service opteed_fast
196INFO:    BL31: Preparing for EL3 exit to normal world
197INFO:    Entry point address = 0x600000
198INFO:    SPSR = 0x3c9
199
200
201U-Boot 2020.01-rc1-00225-g34b681327f (Nov 14 2019 - 10:58:47 +0800)
202
203Model: Firefly ROC-RK3308-CC board
204DRAM:  254 MiB
205MMC:   dwmmc@ff480000: 0, dwmmc@ff490000: 1
206rockchip_dnl_key_pressed read adc key val failed
207Net:   No ethernet found.
208Hit any key to stop autoboot:  0
209Card did not respond to voltage select!
210switch to partitions #0, OK
211mmc1(part 0) is current device
212Scanning mmc 1:4...
213Found /extlinux/extlinux.conf
214Retrieving file: /extlinux/extlinux.conf
215151 bytes read in 3 ms (48.8 KiB/s)
2161:      kernel-mainline
217Retrieving file: /Image
21814737920 bytes read in 377 ms (37.3 MiB/s)
219append: earlycon=uart8250,mmio32,0xff0c0000 console=ttyS2,1500000n8
220Retrieving file: /rk3308-roc-cc.dtb
22128954 bytes read in 4 ms (6.9 MiB/s)
222Flattened Device Tree blob at 01f00000
223Booting using the fdt blob at 0x1f00000
224## Loading Device Tree to 000000000df3a000, end 000000000df44119 ... OK
225
226Starting kernel ...
227[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd042]
228[    0.000000] Linux version 5.4.0-rc1-00040-g4dc2d508fa47-dirty (andy@B150) (gcc version 6.3.1 20170404 (Linaro GCC 6.3-209
229[    0.000000] Machine model: Firefly ROC-RK3308-CC board
230[    0.000000] earlycon: uart8250 at MMIO32 0x00000000ff0c0000 (options '')
231[    0.000000] printk: bootconsole [uart8250] enabled
232
233Booting from an SD card
234=======================
235
236To write an image that boots from an SD card (assumed to be /dev/sdc):
237
238   ./firefly-rk3288/tools/mkimage -n rk3288 -T rksd -d \
239	firefly-rk3288/spl/u-boot-spl-dtb.bin out && \
240   sudo dd if=out of=/dev/sdc seek=64 && \
241   sudo dd if=firefly-rk3288/u-boot-dtb.img of=/dev/sdc seek=16384
242
243This puts the Rockchip header and SPL image first and then places the U-Boot
244image at block 16384 (i.e. 8MB from the start of the SD card). This
245corresponds with this setting in U-Boot:
246
247   #define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR	0x4000
248
249Put this SD (or micro-SD) card into your board and reset it. You should see
250something like:
251
252   U-Boot 2016.01-rc2-00309-ge5bad3b-dirty (Jan 02 2016 - 23:41:59 -0700)
253
254   Model: Radxa Rock 2 Square
255   DRAM:  2 GiB
256   MMC:   dwmmc@ff0f0000: 0, dwmmc@ff0c0000: 1
257   *** Warning - bad CRC, using default environment
258
259   In:    serial
260   Out:   vop@ff940000.vidconsole
261   Err:   serial
262   Net:   Net Initialization Skipped
263   No ethernet found.
264   Hit any key to stop autoboot:  0
265   =>
266
267The rockchip bootrom can load and boot an initial spl, then continue to
268load a second-stage bootloader (ie. U-Boot) as soon as the control is returned
269to the bootrom. Both the RK3288 and the RK3036 use this special boot sequence.
270The configuration option enabling this is:
271
272	CONFIG_SPL_ROCKCHIP_BACK_TO_BROM=y
273
274You can create the image via the following operations:
275
276   ./firefly-rk3288/tools/mkimage -n rk3288 -T rksd -d \
277	firefly-rk3288/spl/u-boot-spl-dtb.bin out && \
278   cat firefly-rk3288/u-boot-dtb.bin >> out && \
279   sudo dd if=out of=/dev/sdc seek=64
280
281Or:
282   ./firefly-rk3288/tools/mkimage -n rk3288 -T rksd -d \
283	firefly-rk3288/spl/u-boot-spl-dtb.bin:firefly-rk3288/u-boot-dtb.bin \
284	out && \
285   sudo dd if=out of=/dev/sdc seek=64
286
287If you have an HDMI cable attached you should see a video console.
288
289For evb_rk3036 board:
290	./evb-rk3036/tools/mkimage -n rk3036 -T rksd  -d evb-rk3036/spl/u-boot-spl.bin out && \
291	cat evb-rk3036/u-boot-dtb.bin >> out && \
292	sudo dd if=out of=/dev/sdc seek=64
293
294Or:
295	./evb-rk3036/tools/mkimage -n rk3036 -T rksd -d \
296		evb-rk3036/spl/u-boot-spl.bin:evb-rk3036/u-boot-dtb.bin out && \
297	sudo dd if=out of=/dev/sdc seek=64
298
299Note: rk3036 SDMMC and debug uart use the same iomux, so if you boot from SD, the
300      debug uart must be disabled
301
302
303Booting from an SD card on RK3288 with TPL
304==========================================
305
306Since the size of SPL can't be exceeded 0x8000 bytes in RK3288, it is not possible add
307new SPL features like Falcon mode or etc.
308
309So introduce TPL so-that adding new features to SPL is possible because now TPL should
310run minimal with code like DDR, clock etc and rest of new features in SPL.
311
312As of now TPL is added on Vyasa-RK3288 board.
313
314To write an image that boots from an SD card (assumed to be /dev/mmcblk0):
315
316    sudo dd if=idbloader.img of=/dev/mmcblk0 seek=64 &&
317    sudo dd if=u-boot-dtb.img of=/dev/mmcblk0 seek=16384
318
319Booting from an SD card on RK3188
320=================================
321
322For rk3188 boards the general storage onto the card stays the same as
323described above, but the image creation needs a bit more care.
324
325The bootrom of rk3188 expects to find a small 1kb loader which returns
326control to the bootrom, after which it will load the real loader, which
327can then be up to 29kb in size and does the regular ddr init.  This is
328handled by a single image (built as the SPL stage) that tests whether
329it is handled for the first or second time via code executed from the
330boot0-hook.
331
332Additionally the rk3188 requires everything the bootrom loads to be
333rc4-encrypted. Except for the very first stage the bootrom always reads
334and decodes 2kb pages, so files should be sized accordingly.
335
336# copy tpl, pad to 1020 bytes and append spl
337tools/mkimage -n rk3188 -T rksd -d spl/u-boot-spl.bin out
338
339# truncate, encode and append u-boot.bin
340truncate -s %2048 u-boot.bin
341cat u-boot.bin | split -b 512 --filter='openssl rc4 -K 7C4E0304550509072D2C7B38170D1711' >> out
342
343Booting from an SD card on Pine64 Rock64 (RK3328)
344=================================================
345
346For Rock64 rk3328 board the following three parts are required:
347TPL, SPL, and the u-boot image tree blob.
348
349  - Write TPL/SPL image at 64 sector
350
351    => sudo dd if=idbloader.img of=/dev/mmcblk0 seek=64
352
353  - Write u-boot image tree blob at 16384 sector
354
355    => sudo dd if=u-boot.itb of=/dev/mmcblk0 seek=16384
356
357Booting from an SD card on RK3399
358=================================
359
360To write an image that boots from an SD card (assumed to be /dev/sdc):
361
362Option 1: Package the image with Rockchip miniloader:
363
364  - Create idbloader.img
365
366    => cd /path/to/u-boot
367    => ./tools/mkimage  -n rk3399 -T rksd -d /path/to/rkbin/bin/rk33/rk3399_ddr_800MHz_v1.20.bin idbloader.img
368    => cat /path/to/rkbin/bin/rk33/rk3399_miniloader_v1.19.bin >> idbloader.img
369
370  - Write idbloader.img at 64 sector
371
372    => sudo dd if=idbloader.img of=/dev/sdc seek=64
373
374  - Write trust.img at 24576
375
376    => sudo dd if=trust.img of=/dev/sdc seek=24576
377
378  - Write uboot.img at 16384 sector
379
380    => sudo dd if=uboot.img of=/dev/sdc seek=16384
381    => sync
382
383Put this SD (or micro-SD) card into your board and reset it. You should see
384something like:
385
386DDR Version 1.20 20190314
387In
388Channel 0: DDR3, 933MHz
389Bus Width=32 Col=10 Bank=8 Row=15 CS=1 Die Bus-Width=16 Size=1024MB
390no stride
391ch 0 ddrconfig = 0x101, ddrsize = 0x20
392pmugrf_os_reg[2] = 0x10006281, stride = 0x17
393OUT
394Boot1: 2019-03-14, version: 1.19
395CPUId = 0x0
396ChipType = 0x10, 239
397mmc: ERROR: SDHCI ERR:cmd:0x102,stat:0x18000
398mmc: ERROR: Card did not respond to voltage select!
399emmc reinit
400mmc: ERROR: SDHCI ERR:cmd:0x102,stat:0x18000
401mmc: ERROR: Card did not respond to voltage select!
402emmc reinit
403mmc: ERROR: SDHCI ERR:cmd:0x102,stat:0x18000
404mmc: ERROR: Card did not respond to voltage select!
405SdmmcInit=2 1
406mmc0:cmd5,20
407SdmmcInit=0 0
408BootCapSize=0
409UserCapSize=60543MB
410FwPartOffset=2000 , 0
411StorageInit ok = 45266
412SecureMode = 0
413SecureInit read PBA: 0x4
414SecureInit read PBA: 0x404
415SecureInit read PBA: 0x804
416SecureInit read PBA: 0xc04
417SecureInit read PBA: 0x1004
418SecureInit read PBA: 0x1404
419SecureInit read PBA: 0x1804
420SecureInit read PBA: 0x1c04
421SecureInit ret = 0, SecureMode = 0
422atags_set_bootdev: ret:(0)
423GPT 0x3380ec0 signature is wrong
424recovery gpt...
425GPT 0x3380ec0 signature is wrong
426recovery gpt fail!
427LoadTrust Addr:0x4000
428No find bl30.bin
429Load uboot, ReadLba = 2000
430hdr 0000000003380880 + 0x0:0x88,0x41,0x3e,0x97,0xe6,0x61,0x54,0x23,0xe9,0x5a,0xd1,0x2b,0xdc,0x2f,0xf9,0x35,
431
432Load OK, addr=0x200000, size=0x9c9c0
433RunBL31 0x10000
434NOTICE:  BL31: v1.3(debug):370ab80
435NOTICE:  BL31: Built : 09:23:41, Mar  4 2019
436NOTICE:  BL31: Rockchip release version: v1.1
437INFO:    GICv3 with legacy support detected. ARM GICV3 driver initialized in EL3
438INFO:    Using opteed sec cpu_context!
439INFO:    boot cpu mask: 0
440INFO:    plat_rockchip_pmu_init(1181): pd status 3e
441INFO:    BL31: Initializing runtime services
442INFO:    BL31: Initializing BL32
443INF [0x0] TEE-CORE:init_primary_helper:337: Initializing (1.1.0-195-g8f090d20 #6 Fri Dec  7 06:11:20 UTC 2018 aarch64)
444
445INF [0x0] TEE-CORE:init_primary_helper:338: Release version: 1.2
446
447INF [0x0] TEE-CORE:init_teecore:83: teecore inits done
448INFO:    BL31: Preparing for EL3 exit to normal world
449INFO:    Entry point address = 0x200000
450INFO:    SPSR = 0x3c9
451
452
453U-Boot 2019.04-rc4-00136-gfd121f9641-dirty (Apr 16 2019 - 14:02:47 +0530)
454
455Model: FriendlyARM NanoPi NEO4
456DRAM:  1022 MiB
457MMC:   dwmmc@fe310000: 2, dwmmc@fe320000: 1, sdhci@fe330000: 0
458Loading Environment from MMC... *** Warning - bad CRC, using default environment
459
460In:    serial@ff1a0000
461Out:   serial@ff1a0000
462Err:   serial@ff1a0000
463Model: FriendlyARM NanoPi NEO4
464Net:   eth0: ethernet@fe300000
465Hit any key to stop autoboot:  0
466=>
467
468Option 2: Package the image with SPL:
469
470  - Prefix rk3399 header to SPL image
471
472    => cd /path/to/u-boot
473    => ./tools/mkimage -n rk3399 -T rksd -d spl/u-boot-spl-dtb.bin out
474
475  - Write prefixed SPL at 64th sector
476
477    => sudo dd if=out of=/dev/sdc seek=64
478
479  - Write U-Boot proper at 16384 sector
480
481    => sudo dd if=u-boot.itb of=/dev/sdc seek=16384
482    => sync
483
484Put this SD (or micro-SD) card into your board and reset it. You should see
485something like:
486
487U-Boot SPL board init
488Trying to boot from MMC1
489
490
491U-Boot 2019.01-00004-g14db5ee998 (Mar 11 2019 - 13:18:41 +0530)
492
493Model: Orange Pi RK3399 Board
494DRAM:  2 GiB
495MMC:   dwmmc@fe310000: 2, dwmmc@fe320000: 1, sdhci@fe330000: 0
496Loading Environment from MMC... OK
497In:    serial@ff1a0000
498Out:   serial@ff1a0000
499Err:   serial@ff1a0000
500Model: Orange Pi RK3399 Board
501Net:   eth0: ethernet@fe300000
502Hit any key to stop autoboot:  0
503=>
504
505Option 3: Package the image with TPL:
506
507  - Write tpl+spl at 64th sector
508
509    => sudo dd if=idbloader.img of=/dev/sdc seek=64
510
511  - Write U-Boot proper at 16384 sector
512
513    => sudo dd if=u-boot.itb of=/dev/sdc seek=16384
514    => sync
515
516Put this SD (or micro-SD) card into your board and reset it. You should see
517something like:
518
519U-Boot TPL board init
520Trying to boot from BOOTROM
521Returning to boot ROM...
522
523U-Boot SPL board init
524Trying to boot from MMC1
525
526
527U-Boot 2019.07-rc1-00241-g5b3244767a (May 08 2019 - 10:51:06 +0530)
528
529Model: Orange Pi RK3399 Board
530DRAM:  2 GiB
531MMC:   dwmmc@fe310000: 2, dwmmc@fe320000: 1, sdhci@fe330000: 0
532Loading Environment from MMC... OK
533In:    serial@ff1a0000
534Out:   serial@ff1a0000
535Err:   serial@ff1a0000
536Model: Orange Pi RK3399 Board
537Net:   eth0: ethernet@fe300000
538Hit any key to stop autoboot:  0
539=>
540
541Using fastboot on rk3288
542========================
543- Write GPT partition layout to mmc device which fastboot want to use it to
544store the image
545
546        => gpt write mmc 1 $partitions
547
548- Invoke fastboot command to prepare
549
550        => fastboot 1
551
552- Start fastboot request on PC
553
554        fastboot -i 0x2207 flash loader evb-rk3288/spl/u-boot-spl-dtb.bin
555
556You should see something like:
557
558        => fastboot 1
559        WARNING: unknown variable: partition-type:loader
560        Starting download of 357796 bytes
561        ..
562        downloading of 357796 bytes finished
563        Flashing Raw Image
564        ........ wrote 357888 bytes to 'loader'
565
566Booting from SPI
567================
568
569To write an image that boots from SPI flash (e.g. for the Haier Chromebook or
570Bob):
571
572   ./chromebook_jerry/tools/mkimage -n rk3288 -T rkspi \
573	-d chromebook_jerry/spl/u-boot-spl-dtb.bin spl.bin && \
574   dd if=spl.bin of=spl-out.bin bs=128K conv=sync && \
575   cat spl-out.bin chromebook_jerry/u-boot-dtb.img >out.bin && \
576   dd if=out.bin of=out.bin.pad bs=4M conv=sync
577
578This converts the SPL image to the required SPI format by adding the Rockchip
579header and skipping every second 2KB block. Then the U-Boot image is written at
580offset 128KB and the whole image is padded to 4MB which is the SPI flash size.
581The position of U-Boot is controlled with this setting in U-Boot:
582
583   #define CONFIG_SYS_SPI_U_BOOT_OFFS	0x20000
584
585If you have a Dediprog em100pro connected then you can write the image with:
586
587      sudo em100 -s -c GD25LQ32 -d out.bin.pad -r
588
589When booting you should see something like:
590
591   U-Boot SPL 2015.07-rc2-00215-g9a58220-dirty (Jun 23 2015 - 12:11:32)
592
593
594   U-Boot 2015.07-rc2-00215-g9a58220-dirty (Jun 23 2015 - 12:11:32 -0600)
595
596   Model: Google Jerry
597   DRAM:  2 GiB
598   MMC:
599   Using default environment
600
601   In:    serial@ff690000
602   Out:   serial@ff690000
603   Err:   serial@ff690000
604   =>
605
606Future work
607===========
608
609Immediate priorities are:
610
611- USB host
612- USB device
613- Run CPU at full speed (code exists but we only see ~60 DMIPS maximum)
614- NAND flash
615- Boot U-Boot proper over USB OTG (at present only SPL works)
616
617
618Development Notes
619=================
620
621There are plenty of patches in the links below to help with this work.
622
623[1] https://github.com/rkchrome/uboot.git
624[2] https://github.com/linux-rockchip/u-boot-rockchip.git branch u-boot-rk3288
625[3] https://github.com/linux-rockchip/rkflashtool.git
626[4] http://wiki.t-firefly.com/index.php/Firefly-RK3288/Serial_debug/en
627
628rkimage
629-------
630
631rkimage.c produces an SPL image suitable for sending directly to the boot ROM
632over USB OTG. This is a very simple format - just the string RK32 (as 4 bytes)
633followed by u-boot-spl-dtb.bin.
634
635The boot ROM loads image to 0xff704000 which is in the internal SRAM. The SRAM
636starts at 0xff700000 and extends to 0xff718000 where we put the stack.
637
638rksd
639----
640
641rksd.c produces an image consisting of 32KB of empty space, a header and
642u-boot-spl-dtb.bin. The header is defined by 'struct header0_info' although
643most of the fields are unused by U-Boot. We just need to specify the
644signature, a flag and the block offset and size of the SPL image.
645
646The header occupies a single block but we pad it out to 4 blocks. The header
647is encoding using RC4 with the key 7c4e0304550509072d2c7b38170d1711. The SPL
648image can be encoded too but we don't do that.
649
650The maximum size of u-boot-spl-dtb.bin which the boot ROM will read is 32KB,
651or 0x40 blocks. This is a severe and annoying limitation. There may be a way
652around this limitation, since there is plenty of SRAM, but at present the
653board refuses to boot if this limit is exceeded.
654
655The image produced is padded up to a block boundary (512 bytes). It should be
656written to the start of an SD card using dd.
657
658Since this image is set to load U-Boot from the SD card at block offset,
659CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, dd should be used to write
660u-boot-dtb.img to the SD card at that offset. See above for instructions.
661
662rkspi
663-----
664
665rkspi.c produces an image consisting of a header and u-boot-spl-dtb.bin. The
666resulting image is then spread out so that only the first 2KB of each 4KB
667sector is used. The header is the same as with rksd and the maximum size is
668also 32KB (before spreading). The image should be written to the start of
669SPI flash.
670
671See above for instructions on how to write a SPI image.
672
673rkmux.py
674--------
675
676You can use this script to create #defines for SoC register access. See the
677script for usage.
678
679
680Device tree and driver model
681----------------------------
682
683Where possible driver model is used to provide a structure to the
684functionality. Device tree is used for configuration. However these have an
685overhead and in SPL with a 32KB size limit some shortcuts have been taken.
686In general all Rockchip drivers should use these features, with SPL-specific
687modifications where required.
688
689GPT partition layout
690----------------------------
691
692Rockchip use a unified GPT partition layout  in open source support.
693With this GPT partition layout, uboot can be compatilbe with other components,
694like miniloader, trusted-os, arm-trust-firmware.
695
696There are some documents about partitions in the links below.
697http://rockchip.wikidot.com/partitions
698
699--
700Jagan Teki <jagan@amarulasolutions.com>
70127 Mar 2019
702Simon Glass <sjg@chromium.org>
70324 June 2015
704