1.. SPDX-License-Identifier: GPL-2.0+
2
3U-Boot for LibreTech CCs
4========================
5
6LibreTech CC is a single board computer manufactured by Libre Technology
7with the following specifications:
8
9V1:
10
11 - Amlogic S905X ARM Cortex-A53 quad-core SoC @ 1.5GHz
12 - ARM Mali 450 GPU
13 - 2GB DDR3 SDRAM
14 - 10/100 Ethernet
15 - HDMI 2.0 4K/60Hz display
16 - 40-pin GPIO header
17 - 4 x USB 2.0 Host
18 - eMMC, microSD
19 - Infrared receiver
20 - Jack for CVBS and Audio
21
22V2:
23
24 - Added SPI NOR
25 - Removed Jack
26
27Schematics are available on the manufacturer website.
28
29U-Boot compilation
30------------------
31
32.. code-block:: bash
33
34    $ export CROSS_COMPILE=aarch64-none-elf-
35    $ make libretech-cc_defconfig
36    $ make
37
38Use libretech-cc_v2_defconfig for v2.
39
40Image creation
41--------------
42
43To boot the system, u-boot must be combined with several earlier stage
44bootloaders:
45
46* bl2.bin: vendor-provided binary blob
47* bl21.bin: built from vendor u-boot source
48* bl30.bin: vendor-provided binary blob
49* bl301.bin: built from vendor u-boot source
50* bl31.bin: vendor-provided binary blob
51* acs.bin: built from vendor u-boot source
52
53These binaries and the tools required below have been collected and prebuilt
54for convenience at <https://github.com/BayLibre/u-boot/releases/>. These
55apply to both v1 and v2.
56
57Download and extract the libretech-cc release from there, and set FIPDIR to
58point to the `fip` subdirectory.
59
60.. code-block:: bash
61
62    $ export FIPDIR=/path/to/extracted/fip
63
64Alternatively, you can obtain the original vendor u-boot tree which
65contains the required blobs and sources, and build yourself.
66Note that old compilers are required for this to build. The compilers here
67are suggested by Amlogic, and they are 32-bit x86 binaries.
68
69.. code-block:: bash
70
71    $ wget https://releases.linaro.org/archive/13.11/components/toolchain/binaries/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz
72    $ wget https://releases.linaro.org/archive/13.11/components/toolchain/binaries/gcc-linaro-arm-none-eabi-4.8-2013.11_linux.tar.xz
73    $ tar xvfJ gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz
74    $ tar xvfJ gcc-linaro-arm-none-eabi-4.8-2013.11_linux.tar.xz
75    $ export PATH=$PWD/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin:$PWD/gcc-linaro-arm-none-eabi-4.8-2013.11_linux/bin:$PATH
76    $ git clone https://github.com/BayLibre/u-boot.git -b libretech-cc amlogic-u-boot
77    $ cd amlogic-u-boot
78    $ make libretech_cc_defconfig
79    $ make
80    $ export FIPDIR=$PWD/fip
81
82Once you have the binaries available (either through the prebuilt download,
83or having built the vendor u-boot yourself), you can then proceed to glue
84everything together. Go back to mainline U-Boot source tree then :
85
86.. code-block:: bash
87
88    $ mkdir fip
89
90    $ cp $FIPDIR/gxl/bl2.bin fip/
91    $ cp $FIPDIR/gxl/acs.bin fip/
92    $ cp $FIPDIR/gxl/bl21.bin fip/
93    $ cp $FIPDIR/gxl/bl30.bin fip/
94    $ cp $FIPDIR/gxl/bl301.bin fip/
95    $ cp $FIPDIR/gxl/bl31.img fip/
96    $ cp u-boot.bin fip/bl33.bin
97
98    $ $FIPDIR/blx_fix.sh \
99    	fip/bl30.bin \
100    	fip/zero_tmp \
101    	fip/bl30_zero.bin \
102    	fip/bl301.bin \
103    	fip/bl301_zero.bin \
104    	fip/bl30_new.bin \
105    	bl30
106
107    $ $FIPDIR/acs_tool.pyc fip/bl2.bin fip/bl2_acs.bin fip/acs.bin 0
108
109    $ $FIPDIR/blx_fix.sh \
110    	fip/bl2_acs.bin \
111    	fip/zero_tmp \
112    	fip/bl2_zero.bin \
113    	fip/bl21.bin \
114    	fip/bl21_zero.bin \
115    	fip/bl2_new.bin \
116    	bl2
117
118    $ $FIPDIR/gxl/aml_encrypt_gxl --bl3enc --input fip/bl30_new.bin
119    $ $FIPDIR/gxl/aml_encrypt_gxl --bl3enc --input fip/bl31.img
120    $ $FIPDIR/gxl/aml_encrypt_gxl --bl3enc --input fip/bl33.bin
121    $ $FIPDIR/gxl/aml_encrypt_gxl --bl2sig --input fip/bl2_new.bin --output fip/bl2.n.bin.sig
122    $ $FIPDIR/gxl/aml_encrypt_gxl --bootmk \
123    		--output fip/u-boot.bin \
124    		--bl2 fip/bl2.n.bin.sig \
125    		--bl30 fip/bl30_new.bin.enc \
126    		--bl31 fip/bl31.img.enc \
127    		--bl33 fip/bl33.bin.enc
128
129and then write the image to SD with:
130
131.. code-block:: bash
132
133    $ DEV=/dev/your_sd_device
134    $ dd if=fip/u-boot.bin.sd.bin of=$DEV conv=fsync,notrunc bs=512 skip=1 seek=1
135    $ dd if=fip/u-boot.bin.sd.bin of=$DEV conv=fsync,notrunc bs=1 count=444
136
137Note that Amlogic provides aml_encrypt_gxl as a 32-bit x86 binary with no
138source code. Should you prefer to avoid that, there are open source reverse
139engineered versions available:
140
1411. gxlimg <https://github.com/repk/gxlimg>, which comes with a handy
142   Makefile that automates the whole process.
1432. meson-tools <https://github.com/afaerber/meson-tools>
144
145However, these community-developed alternatives are not endorsed by or
146supported by Amlogic.
147