1Allwinner A10 hardware notes 2############################ 3 4- http://linux-sunxi.org 5 6Hardware Information 7==================== 8 9The A10 is a system-on chip. There are many devices based on it, for 10example the CubieBoard and the Rikomagic mk802 (versions I and II). 11 12- ARMv7 Architecture (Cortex-A8) 13- Mali 400MP GPU 14- CedarX VPU 15- SD Card Storage 16- 1GB RAM (DDR) 17- 4GB NAND Flash 18- Video Outputs 19 20 - HDMI Video Output 21 22- Ethernet 23- USB 24 25Setting up the Haiku SD card 26============================ 27 28Not so fun layout here. The A10 boot ROM reads raw blocks from the SD 29card (MBR style), so the bootloader can’t just be dropped in a FAT32 30partition. 31 32- 8KB partition table 33- 24KB SPL loader 34- 512KB u-boot 35- 128KB u-boot environment variables 36- 352KB unused 37- partition 1 – FAT32 or ext2 (anything u-boot can read is fine) 38- partition 2 – BeFS, Haiku filesystem, type ‘eb’ 39 40Note this layout can be a bit different depending on the u-boot version 41used, some versions will store the environment in uEnv.txt in the FAT32 42partition instead. Since everything is loaded from the SD Card, we are 43free to customize the u-boot or even remove it and get haiku_loader 44booting directly. 45 46Boot Partition 47-------------- 48 49Required Files 50~~~~~~~~~~~~~~ 51 52- haiku_loader: Haiku Loader 53- haiku-floppyboot.tgz: Compressed image with Haiku kernel 54 55Booting 56======= 57 581. SOC load SPL 592. SPL loads u-boot 603. u-boot loads and run the kernel 61 62SPL is a small binary (24K) loaded from a fixed location on the SD card. 63It does minimal hardware initializations, then loads u-boot, also from 64the SD card. From there on things go as usual. 65 66In the long term, we can make haiku_loader be an SPL executable on this 67platform, if it fits the 24K size limit, or have a custom stage1 that 68loads it. For now, u-boot can be an useful debugging tool. 69 70Script.bin 71---------- 72 73In order to work on different devices (RAM timings, PIO configs, …), the 74Linux kernels for Allwinner chips use a “script.bin” file. This is 75loaded to RAM at a fixed address by u-boot, then the Kernel parses it 76and uses it to configure the hardware (similar to FDT). 77 78We should probably NOT use this, and convert the script.bin file to an 79FDT instead. The format is known and there are tools to convert the 80binary file to an editable text version and back (bin2fex and fex2bin). 81 82This FEX stuff isn’t merged in mainline Linux, and lives on as Allwinner 83patches. The mainline Linux kernel has some A10 support, rewritten to 84use FDT. We may use the FDT files from there for the most common boards. 85 86Emulation support 87================= 88 89qemu 1.0 has a Cubieoard target which emulates this chip. 90 91Useful links 92============ 93 94Arch Linux instructions on creating a bootable SD card (partition 95layout, etc) 96http://archlinuxarm.org/platforms/armv7/allwinner/cubieboard#qt-platform_tabs-ui-tabs2 97 98Linux SunXi: mainline Linux support for the Allwinner chips. Lots of 99docs on the hardware. http://linux-sunxi.org/ 100