A20-OLinuXino-LIME2
###################

This tutorial will show the details of Olimex A20-OLinuXino-LIME2 board mainline support and other details like
hardware, documentation, schematics are available at `hardware <https://www.olimex.com/Products/OLinuXino/A20/A20-OLinuXino-LIME2/>`_  and `linux-sunxi <https://www.olimex.com/Products/OLinuXino/A20/A20-OLinuXino-LIME2/>`_

Hardware Access
***************
Power supply: External 5V Jack
USB OTG Cable, USB to TTL for debug

.. image:: /images/lime2.jpg

BSP Build
*********
Image building need host to ready with all necessary tools ready, refer `here <https://wiki.amarulasolutions.com/found/host/tools.html#arm>`_

U-Boot
======

::

        git clone git://git.denx.de/u-boot.git
        cd u-boot
        make A20-OLinuXino-Lime2_defconfig && make

Linux
=====

::

        git clone git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 
        cd linux-next 
        make mrproper 
        ARCH=arm sunxi_defconfig 
        ARCH=arm make -j 4 zImage dtbs 

Booting
*******
SD Boot
=======
FEL/USB Boot
============

U-Boot
******

USB Mass Storage gadget
=======================
We can use the board as a USB Mass Storage device:
You will be able to access all the partitions of any block device that is on the board or connected to it,
from your host PC - You will see them as /dev/sdXX, just like connecting a regular USB storage to your PC,
and you'll be able to mount them, and have full read/write access to them.
We can even use it to flash a new U-Boot, re-partition the storage, re-format it, etc.
This is especially useful for updating the internal eMMC.
To do this you need to connect a USB cable between the OTG/Client port of the board and a regular USB Host port on your PC,
and use U-Boot's ums command.

::

        U-Boot SPL 2017.11-00464-g2fac022-dirty (Dec 06 2017 - 11:21:03)
        DRAM: 1024 MiB
        CPU: 912000000Hz, AXI/AHB/APB: 3/2/2
        Trying to boot from MMC1
        U-Boot 2017.11-00464-g2fac022-dirty (Dec 06 2017 - 11:21:03 +0530) Allwinner Technology
        CPU: Allwinner A20 (SUN7I)
        Model: Olimex A20-OLinuXino-LIME2
        I2C: ready
        DRAM: 1 GiB
        MMC: SUNXI SD/MMC: 0
        *** Warning - bad CRC, using default environment
        To exit the ums command and disconnect the USB device press ctrl+c.
        In: serial
        Out: serial
        Err: serial
        musb_usb_probe
        sunxi_musb_init():
        1 sunxi_musb_init():
        2 sunxi_musb_init():
        2.per sunxi_musb_init():
        3 sunxi_musb_init():
        sunxi_musb_disable():
        musb-hdrc:ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk split, HB-ISO Rx, HB-ISO Tx,
        SoftConn)
        musb-hdrc: MHDRC RTL version 0.0
        musb-hdrc: setup fifo_mode 2
        musb-hdrc: 7/11 max ep, 2624/8192 memory
        USB Peripheral mode controller at 01c13000 using PIO, IRQ 0
        Allwinner mUSB OTG (Peripheral)
        SCSI: SATA link 0 timeout.
        AHCI 0001.0100 32 slots 1 ports 3 Gbps 0x1 impl SATA mode
        flags: ncq stag pm led clo only pmp pio slum part ccc apst
        Net: eth0: ethernet@01c50000
        Warning: usb_ether using MAC address from ROM
        , eth1: usb_ether
        starting USB...
        USB0: USB EHCI 1.00
        USB1: USB OHCI 1.0
        USB2: USB EHCI 1.00
        USB3: USB OHCI 1.0
        scanning bus 0 for devices... 1 USB Device(s) found
        scanning bus 2 for devices... 1 USB Device(s) found
        scanning usb for storage devices... 0 Storage Device(s) found
        Hit any key to stop autoboot: 2 0
        => ums 0 mmc 0
        UMS: LUN 0, dev 0, hwpart 0, sector 0x0, count 0xe94000
        sunxi_musb_enable():
        |/musb-hdrc: peripheral reset irq lost!
        -\|/-\/-\|/-\/-\|/-\/-\|/-\/-\|/-\/-\|/


.. code-block:: c

   #include <linux/uinput.h>

   void emit(int fd, int type, int code, int val)
   {
      struct input_event ie;

      ie.type = type;
      ie.code = code;
      ie.value = val;
      /* timestamp values below are ignored */
      ie.time.tv_sec = 0;
      ie.time.tv_usec = 0;

      write(fd, &ie, sizeof(ie));
   }

   int main(void)
   {
      struct uinput_setup usetup;

      int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);


      /*
       * The ioctls below will enable the device that is about to be
       * created, to pass key events, in this case the space key.
       */
      ioctl(fd, UI_SET_EVBIT, EV_KEY);
      ioctl(fd, UI_SET_KEYBIT, KEY_SPACE);

      memset(&usetup, 0, sizeof(usetup));
      usetup.id.bustype = BUS_USB;
      usetup.id.vendor = 0x1234; /* sample vendor */
      usetup.id.product = 0x5678; /* sample product */
      strcpy(usetup.name, "Example device");

      ioctl(fd, UI_DEV_SETUP, &usetup);
      ioctl(fd, UI_DEV_CREATE);

      /*
       * On UI_DEV_CREATE the kernel will create the device node for this
       * device. We are inserting a pause here so that userspace has time
       * to detect, initialize the new device, and can start listening to
       * the event, otherwise it will not notice the event we are about
       * to send. This pause is only needed in our example code!
       */
      sleep(1);

   }