[U-Boot] [PATCH v2] mx6ulevk: Include SDP boot instructions in README

[Breno Matheus Lima]

Add instructions on how to boot mx6ul_14x14_evk_defconfig target
using the Serial Download Protocol.

Add examples from uuu and imx_usb_loader tools.

Signed-off-by: Breno Lima <breno.lima at nxp.com>
---
Changes since v1:
- Added more details on how to calculate address for UUU script.
- Clarified that UUU and imx_usb_loader are 2 different methods.
 board/freescale/mx6ul_14x14_evk/README | 50 ++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/board/freescale/mx6ul_14x14_evk/README b/board/freescale/mx6ul_14x14_evk/README
index 1edccf688c..e101abe48c 100644
--- a/board/freescale/mx6ul_14x14_evk/README
+++ b/board/freescale/mx6ul_14x14_evk/README
@@ -9,6 +9,9 @@ $ make
 
 This will generate the SPL image called SPL and the u-boot.img.
 
+1. Booting via SDCard
+---------------------
+
 - Flash the SPL image into the micro SD card:
 
 sudo dd if=SPL of=/dev/mmcblk0 bs=1k seek=1; sync
@@ -30,3 +33,50 @@ switch label numbers reference).
 
 - Insert the micro SD card in the board, power it up and U-Boot messages should
 come up.
+
+2. Booting via Serial Download Protocol (SDP)
+---------------------------------------------
+
+The mx6ulevk board can boot from USB OTG port using the SDP, target will
+enter in SDP mode in case an SD Card is not connect or boot switches are
+set as below:
+
+Sw602: 0 1
+SW601: x x x x
+
+The following tools can be used to boot via SDP, for both tools you must
+connect an USB cable in USB OTG port.
+
+- Method 1: Universal Update Utility (uuu)
+
+The UUU binary can be downloaded in release tab from link below:
+https://github.com/NXPmicro/mfgtools
+
+The following script should be created to boot SPL + u-boot-dtb.img binaries:
+
+  $ cat uuu_script
+    uuu_version 1.1.4
+
+    SDP: boot -f SPL
+    SDPU: write -f u-boot-dtb.img -addr 0x877fffc0
+    SDPU: jump -addr 0x877fffc0
+    SDPU: done
+
+Please note that the address above is calculated based on SYS_TEXT_BASE address:
+
+0x877fffc0 = 0x87800000 (SYS_TEXT_BASE) - 0x40 (U-Boot proper Header size)
+
+Power on the target and run the following command from U-Boot root directory:
+
+  $ sudo ./uuu uuu_script
+
+- Method 2: imx usb loader tool (imx_usb):
+
+The imx_usb_loader tool can be downloaded in link below:
+https://github.com/boundarydevices/imx_usb_loader
+
+Build the source code and run the following commands from U-Boot root
+directory:
+
+  $ sudo ./imx_usb SPL
+  $ sudo ./imx_usb u-boot-dtb.img
-- 
2.17.1