13-OlinuXino-MICRO info

I recently purchased a 13-OlinuXino-MICRO. The goal is to port MINIX to that board. I therefore am gattering some information here. Document

Datasheets:

User manual: http://dl.linux-sunxi.org/A13/A13%20User%20Manual%20-%20v1.2%20(2013-01-08).pdf

Links:

Serial and serial cable

If you have the link:https://www.olimex.com/Products/Components/Cables/USB-Serial-Cable/USB-Serial-Cable-F/[Olimex USB-SERIAL-CABLE] GND=BLUE, RX(INPUT)=GREEN, TX(OUTPUT)=RED you can connect it the following way:

As usual with serial you need to connect the sending end of the serial to the receiving end of the board.

Formating the SD-card

The device doesn’t have internal storage and boots from the SD-card. The second and third stage loader (SPL and U-Boot) are loaded from the start of the MMC (not on a file system). The default configuration is to create two partitions the first is a FAT formatted one where u-boot will load files from and the second one probably a ext2 partition. But given the bootloaders are not on the FAT you need to reserve some space at the start (I leave 2048 512 byte blokcs at the start as this is the default fdisk offers).

The layout looks something like this:

NAME start block size MBR 0 1 block sunxi-spl.bin 16 20K u-boot.bin 64 170K FAT 2048 20M EXT2 — Rest

fisk -l on your device might look like this:

--------------------------------- Device Boot Start End Blocks Id System /dev/sdc1 2048 43007 20480 b W95 FAT32 /dev/sdc2 43008 990975 473984 83 Linux ---------------------------------

Uboot and booting

git clone https://github.com/linux-sunxi/u-boot-sunxi.git cd u-boot-sunxi make a13_olinuxino CROSS_COMPILE=arm-none-eabi- DEV=/dev/sdXFixMe sudo dd if=spl/sunxi-spl.bin of=$DEV bs=1024 seek=8 sudo dd if=u-boot.bin of=$DEV bs=1024 seek=32

Afther this the device will boot and if you have a serial attached you can see the u-boot command prompt

Kernel and script.bin

script.bin is file used by the sunxi kernel and contains configuration parameters like port GPIO assignments. This file file is created using the fex2bin tool that can be found in the sunxi-tools git repo. You can convert the bin file into something more readable using bin2fex. If you run that you get link:src/script.bin.fex[Ascii version of script.bin].