xref: /openbmc/u-boot/board/logicpd/imx6/README (revision db4a2999)

U-Boot for LogicPD i.MX6 Development Kit
----------------------------------------

This file contains information for the port of U-Boot to the Logic PD Development kit.

Logic PD has an i.MX6 System On Module (SOM) and a correspondong development
board.  SOM has a built-in microSD socket, DDR and NAND flash.  The development kit has
an SMSC Ethernet PHY, serial debug port and a variety of peripherals.

On the intial release, the SOM came with either an i.MX6D or i.MX6Q.

For more details about Logic PD i.MX6 Development kit, visit:
https://www.logicpd.com/

Building U-Boot for Logic PD Development Kit
--------------------------------------------
To build U-Boot for the Dual and Quad variants:

 make imx6q_logic_defconfig
 make u-boot.imx ARCH=arm CROSS_COMPILE=arm-linux-


Flashing U-Boot into the SD card
--------------------------------
U-Boot is now building with SPL enabled which means there are two files to
load into the SD card. Make sure the card is formatted with at least two
partitions with the first partition being FAT32. First copy u-boot-dtb.img
to the first partition then burn SPL to the SD card with dd.
The SPL portion is programmed into a certain location for use by the internal
bootROM and it cannot be changed.  The following instructions assume the SD
card is located as /dev/sdb.

  cp u-boot-dtb.img /dev/media/logic/boot
  sudo dd if=SPL of=/dev/sdb bs=1k seek=1 oflag=sync status=none && sync


Flashing U-Boot into NAND
-------------------------
Once in Linux with MTD support for the NAND on /dev/mtd0, program U-Boot with the following:
with:

  kobs-ng init -v -x u-boot-dtb.imx


Using Falcon Mode
-----------------
With Falcon Mode enabled, U-Boot can be bypassed by having SPL directly load
the kernel.  The device tree, Kernel and boot args must first be configured,
and stored to a file on the micro SD card called 'args'
The kernel uImage is built with LOAD_ADDR=0x12000000 and the device tree is
assummed to be imx6q-logicpd.dtb.

By default the mmcroot is set to the baseboard.

  # Establish bootargs
  run mmcargs

  # Load Linux Kernel uImage
  fatload mmc 1 $loadaddr uImage

  # Load Device Tree
  run loadfdt

  # Setup the blob that will get passed to the kernel
  spl export fdt ${loadaddr} - ${fdt_addr_r}

  # Note the starting and ending address of the updated device tree.
  # for this example:
  # Loading Device Tree to 1ffdf000, end 1fff038b ... OK
  # Notice that 0x1fff038b - 1ffdf000 = 0x1138b
  # now Add 1, so the length is 0x1138c.

  fatwrite mmc 1 0x1ffdf000 args 0x1138c

  # Reset the board and it will bypass U-Boot and SPL will directly boot
  # the uImage

To interrupt the boot sequence and force U-Boot to load, hold the 'c' button
while starting.

Additional Support Documentation can be found at:
https://support.logicpd.com/