1Allwinner ARMv8 SoCs
2====================
3
4Trusted Firmware-A (TF-A) implements the EL3 firmware layer for Allwinner
5SoCs with ARMv8 cores. Only BL31 is used to provide proper EL3 setup and
6PSCI runtime services.
7
8Building TF-A
9-------------
10
11To build for machines with an A64 or H5 SoC:
12
13.. code:: shell
14
15    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1 bl31
16
17To build for machines with an H6 SoC:
18
19.. code:: shell
20
21    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_h6 DEBUG=1 bl31
22
23To build for machines with an H616 or H313 SoC:
24
25.. code:: shell
26
27    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_h616 DEBUG=1 bl31
28
29
30Installation
31------------
32
33U-Boot's SPL acts as a loader, loading both BL31 and BL33 (typically U-Boot).
34Loading is done from SD card, eMMC or SPI flash, also via an USB debug
35interface (FEL).
36
37After building bl31.bin, the binary must be fed to the U-Boot build system
38to include it in the FIT image that the SPL loader will process.
39bl31.bin can be either copied (or sym-linked) into U-Boot's root directory,
40or the environment variable BL31 must contain the binary's path.
41See the respective `U-Boot documentation`_ for more details.
42
43.. _U-Boot documentation: https://gitlab.denx.de/u-boot/u-boot/-/blob/master/board/sunxi/README.sunxi64
44
45Memory layout
46-------------
47
48A64, H5 and H6 SoCs
49~~~~~~~~~~~~~~~~~~~
50
51BL31 lives in SRAM A2, which is documented to be accessible from secure
52world only. Since this SRAM region is very limited (48 KB), we take
53several measures to reduce memory consumption. One of them is to confine
54BL31 to only 28 bits of virtual address space, which reduces the number
55of required page tables (each occupying 4KB of memory).
56The mapping we use on those SoCs is as follows:
57
58::
59
60   0 64K         16M             1GB         1G+160M     physical address
61   +-+------+-+---+------+--...---+-------+----+------+----------
62   |B|      |S|///|      |//...///|       |////|      |
63   |R| SRAM |C|///| dev  |//...///| (sec) |////| BL33 |  DRAM ...
64   |O|      |P|///| MMIO |//...///| DRAM  |////|      |
65   |M|      | |///|      |//...///| (32M) |////|      |
66   +-+------+-+---+------+--...---+-------+----+------+----------
67   | |      | |   |      |       /       /   /      /
68   | |      | |   |      |      /       /  /      /
69   | |      | |   |      |     /       / /      /
70   | |      | |   |      |    /       //      /
71   | |      | |   |      |   /       /      /
72   +-+------+-+---+------+--+-------+------+
73   |B|      |S|///|      |//|       |      |
74   |R| SRAM |C|///| dev  |//|  sec  | BL33 |
75   |O|      |P|///| MMIO |//| DRAM  |      |
76   |M|      | |///|      |//|       |      |
77   +-+------+-+---+------+--+-------+------+
78   0 64K         16M       160M    192M  256M             virtual address
79
80
81H616 SoC
82~~~~~~~~
83
84The H616 lacks the secure SRAM region present on the other SoCs, also
85lacks the "ARISC" management processor (SCP) we use. BL31 thus needs to
86run from DRAM, which prevents our compressed virtual memory map described
87above. Since running in DRAM also lifts the restriction of the limited
88SRAM size, we use the normal 1:1 mapping with 32 bits worth of virtual
89address space. So the virtual addresses used in BL31 match the physical
90addresses as presented above.
91
92Trusted OS dispatcher
93---------------------
94
95One can boot Trusted OS(OP-TEE OS, bl32 image) along side bl31 image on Allwinner A64.
96
97In order to include the 'opteed' dispatcher in the image, pass 'SPD=opteed' on the command line
98while compiling the bl31 image and make sure the loader (SPL) loads the Trusted OS binary to
99the beginning of DRAM (0x40000000).
100