blob: 55534152708ad5b7fee2478ecdc6535ef33e02c1 [file] [log] [blame]
Andre Przywaraa8685982016-07-08 15:25:23 +01001Pine64 board README
2====================
3
4The Pine64(+) is a single board computer equipped with an AArch64 capable ARMv8
5compliant Allwinner A64 SoC.
6This chip has ARM Cortex A-53 cores and thus can run both in AArch32
7(compatible to 32-bit ARMv7) and AArch64 modes. Upon reset the SoC starts
8in AArch32 mode and executes 32-bit code from the Boot ROM (BROM).
9This has some implications on U-Boot.
10
11Quick start
12============
13- Get hold of a boot0.img file (see below for more details).
14- Get the boot0img tool source from the tools directory in [1] and compile
15 that on your host.
16- Build U-Boot:
17$ export CROSS_COMPILE=aarch64-linux-gnu-
18$ make pine64_plus_defconfig
19$ make
20- You also need a compiled ARM Trusted Firmware (ATF) binary. Checkout the
21 "allwinner" branch from the github repository [2] and build it:
22$ export CROSS_COMPILE=aarch64-linux-gnu-
23$ make PLAT=sun50iw1p1 DEBUG=1 bl31
24 The resulting binary is build/sun50iw1p1/debug/bl31.bin.
25
26Now put an empty (or disposable) micro SD card in your card reader and learn
27its device file name, replacing /dev/sd<x> below with the result (that could
28be /dev/mmcblk<x> as well):
29
30$ ./boot0img --device /dev/sd<x> -e -u u-boot.bin -B boot0.img \
31 -d trampoline64:0x44000 -s bl31.bin -a 0x44008 -p 100
32(either copying the respective files to the working directory or specifying
33the paths directly)
34
35This will create a new partition table (with a 100 MB FAT boot partition),
36copies boot0.img, ATF and U-Boot to the proper locations on the SD card and
37will fill in the magic Allwinner header to be recognized by boot0.
38Prefix the above call with "sudo" if you don't have write access to the
39uSD card. You can also use "-o output.img" instead of "--device /dev/sd<x>"
40to create an image file and "dd" that to the uSD card.
41Omitting the "-p" option will skip the partition table.
42
43Now put this uSD card in the board and power it on. You should be greeted by
44the U-Boot prompt.
45
46
47Main U-Boot
48============
49The main U-Boot proper is a real 64-bit ARMv8 port and runs entirely in the
5064-bit AArch64 mode. It can load any AArch64 code, EFI applications or arm64
51Linux kernel images (often named "Image") using the booti command.
52Launching 32-bit code and kernels is technically possible, though not without
53drawbacks (or hacks to avoid them) and currently not implemented.
54
55SPL support
56============
57The main task of the SPL support is to bring up the DRAM controller and make
58DRAM actually accessible. At the moment there is no documentation or source
59code available which would do this.
60There are currently two ways to overcome this situation: using a tainted 32-bit
61SPL (involving some hacks and resulting in a non-redistributable binary, thus
62not described here) or using the Allwinner boot0 blob.
63
64boot0 method
65-------------
66boot0 is Allwiner's secondary program loader and it can be used as some kind
67of SPL replacement to get U-Boot up and running.
68The binary is a 32 KByte blob and contained on every Pine64 image distributed
69so far. It can be easily extracted from a micro SD card or an image file:
70# dd if=/dev/sd<x> of=boot0.bin bs=8k skip=1 count=4
71where /dev/sd<x> is the device name of the uSD card or the name of the image
72file. Apparently Allwinner allows re-distribution of this proprietary code
73as-is.
74For the time being this boot0 blob is the only redistributable way of making
75U-Boot work on the Pine64. Beside loading the various parts of the (original)
76firmware it also switches the core into AArch64 mode.
77The original boot0 code looks for U-Boot at a certain place on an uSD card
78(at 19096 KB), also it expects a header with magic bytes and a checksum.
79There is a tool called boot0img[1] which takes a boot0.bin image and a compiled
80U-Boot binary (plus other binaries) and will populate that header accordingly.
81To make space for the magic header, the pine64_plus_defconfig will make sure
82there is sufficient space at the beginning of the U-Boot binary.
83boot0img will also take care of putting the different binaries at the right
84places on the uSD card and works around unused, but mandatory parts by using
85trampoline code. See the output of "boot0img -h" for more information.
86boot0img can also patch boot0 to avoid loading U-Boot from 19MB, instead
87fetching it from just behind the boot0 binary (-B option).
88
89FEL boot
90=========
91FEL is the name of the Allwinner defined USB boot protocol built-in the
92mask ROM of most Allwinner SoCs. It allows to bootstrap a board solely
93by using the USB-OTG interface and a host port on another computer.
94Since FEL boot does not work with boot0, it requires the libdram hack, which
95is not described here.
96
97[1] https://github.com/apritzel/pine64/
98[2] https://github.com/apritzel/arm-trusted-firmware.git