1. [u-boot.git] / board / sunxi / README.pine64
2. Allwinner 64-bit boards README
1 Pine64 board README
2 ====================
3
4 The Pine64(+) is a single board computer equipped with an AArch64 capable ARMv8
5 compliant Allwinner A64 SoC.
6 This 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
8 in AArch32 mode and executes 32-bit code from the Boot ROM (BROM).
9 This has some implications on U-Boot.
10
11 Quick 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:
$ git clone https://github.com/u-boot/u-boot.git
$ cd u-boot
$ export CROSS_COMPILE=aarch64-linux-gun-
$ make pine64_plus_defconfig
$ make18 $ 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:
$ git clone https://github.com/apritzel/arm-trusted-firmware.git
$ cd arm-trusted-firmware
$ git checkout allwinner
$ export CROSS_COMPILE=aarch64-linux-gnu-
$ make PLAT=sun50iw1p1 DEBUG=1 bl3123 $ make PLAT=sun50iw1p1 DEBUG=1 bl31
24 The resulting binary is build/sun50iw1p1/debug/bl31.bin.
25
26 Now put an empty (or disposable) micro SD card in your card reader and learn
27 its device file name, replacing /dev/sd
28 be /dev/mmcblk
29
30 $ ./boot0img --device /dev/sd
31 -d trampoline64:0x44000 -s bl31.bin -a 0x44008 -p 100
32 (either copying the respective files to the working directory or specifying
33 the paths directly)
34
35 This will create a new partition table (with a 100 MB FAT boot partition),
36 copies boot0.img, ATF and U-Boot to the proper locations on the SD card and
37 will fill in the magic Allwinner header to be recognized by boot0.
38 Prefix the above call with "sudo" if you don't have write access to the
39 uSD card. You can also use "-o output.img" instead of "--device /dev/sd
40 to create an image file and "dd" that to the uSD card.
41 Omitting the "-p" option will skip the partition table.
42
43 Now put this uSD card in the board and power it on. You should be greeted by
44 the U-Boot prompt.
45
46
47 Main U-Boot
48 ============
49 The main U-Boot proper is a real 64-bit ARMv8 port and runs entirely in the
50 64-bit AArch64 mode. It can load any AArch64 code, EFI applications or arm64
51 Linux kernel images (often named "Image") using the booti command.
52 Launching 32-bit code and kernels is technically possible, though not without
53 drawbacks (or hacks to avoid them) and currently not implemented.
54
55 SPL support
56 ============
57 The main task of the SPL support is to bring up the DRAM controller and make
58 DRAM actually accessible. At the moment there is no documentation or source
59 code available which would do this.
60 There are currently two ways to overcome this situation: using a tainted 32-bit
61 SPL (involving some hacks and resulting in a non-redistributable binary, thus
62 not described here) or using the Allwinner boot0 blob.
63
64 boot0 method
65 -------------
66 boot0 is Allwiner's secondary program loader and it can be used as some kind
67 of SPL replacement to get U-Boot up and running.
68 The binary is a 32 KByte blob and contained on every Pine64 image distributed
69 so far. It can be easily extracted from a micro SD card or an image file:
70 # dd if=/dev/sd
71 where /dev/sd
72 file. Apparently Allwinner allows re-distribution of this proprietary code
73 as-is.
74 For the time being this boot0 blob is the only redistributable way of making
75 U-Boot work on the Pine64. Beside loading the various parts of the (original)
76 firmware it also switches the core into AArch64 mode.
77 The 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.
79 There is a tool called boot0img[1] which takes a boot0.bin image and a compiled
80 U-Boot binary (plus other binaries) and will populate that header accordingly.
81 To make space for the magic header, the pine64_plus_defconfig will make sure
82 there is sufficient space at the beginning of the U-Boot binary.
83 boot0img will also take care of putting the different binaries at the right
84 places on the uSD card and works around unused, but mandatory parts by using
85 trampoline code. See the output of "boot0img -h" for more information.
86 boot0img can also patch boot0 to avoid loading U-Boot from 19MB, instead
87 fetching it from just behind the boot0 binary (-B option).
88
89 FEL boot
90 =========
91 FEL is the name of the Allwinner defined USB boot protocol built-in the
92 mask ROM of most Allwinner SoCs. It allows to bootstrap a board solely
93 by using the USB-OTG interface and a host port on another computer.
94 Since FEL boot does not work with boot0, it requires the libdram hack, which
95 is not described here.
96
97 [1] https://github.com/apritzel/pine64/
98 [2] https://github.com/apritzel/arm-trusted-firmware.git
