|  | U-Boot for the Boundary Devices Nitrogen6X and | 
|  | Freescale i.MX6Q SabreLite boards | 
|  |  | 
|  | This file contains information for the port of | 
|  | U-Boot to the Boundary Devices Nitrogen6X and | 
|  | Freescale i.MX6Q SabreLite boards. | 
|  |  | 
|  | 1. Boot source, boot from SPI NOR | 
|  | --------------------------------- | 
|  | The configuration in this directory supports both the | 
|  | Nitrogen6X and Freescale SabreLite board, but in a | 
|  | different fashion from Freescale's implementation in | 
|  | board/freescale/mx6qsabrelite. | 
|  |  | 
|  | In particular, this image supports booting from SPI NOR | 
|  | and saving the environment to SPI NOR. | 
|  |  | 
|  | It does not support 'boot from SD' at offset 0x400 | 
|  | except through the 'bmode' command. | 
|  | http://lists.denx.de/pipermail/u-boot/2012-August/131151.html | 
|  |  | 
|  | 2. Boots using 6x_bootscript on SATA or SD card | 
|  | ----------------------------------------------- | 
|  | The default bootcmd for these boards is configured | 
|  | to look for and source a boot script named '6x_bootscript' | 
|  | in the root of the first partition of the following | 
|  | devices: | 
|  |  | 
|  | sata 0 | 
|  | mmc 0 | 
|  | mmc 1 | 
|  |  | 
|  | They're searched in the order listed above, trying both the | 
|  | ext2 and fat filesystems. | 
|  |  | 
|  | 2. Maintaining the SPI NOR | 
|  | -------------------------- | 
|  | A couple of convenience commands | 
|  |  | 
|  | clearenv - clear environment to factory default | 
|  | upgradeu - look and source a boot script named | 
|  | '6x_upgrade' to upgrade the U-Boot version | 
|  | in SPI NOR. The search is the same as for | 
|  | 6x_bootscript described above. | 
|  |  | 
|  | 3. Display support | 
|  | ------------------ | 
|  | U-Boot support for the following displays is configured by | 
|  | default: | 
|  |  | 
|  | HDMI           - 1024 x 768 for maximum compatibility | 
|  | Hannstar-XGA   - 1024 x 768 LVDS (Freescale part number MCIMX-LVDS1) | 
|  | wsvga-lvds     - 1024 x 600 LVDS (Boundary p/n Nit6X_1024x600) | 
|  | wvga-rgb       - 800 x 480 RGB (Boundary p/n Nit6X_800x480) | 
|  |  | 
|  | Since the ipuv3_fb display driver currently supports only a single display, | 
|  | this code auto-detects panel by probing the HDMI Phy for Hot Plug Detect | 
|  | or the I2C touch controller of the LVDS and RGB displays in the priority | 
|  | listed above. | 
|  |  | 
|  | Setting 'panel' environment variable to one of the names above will | 
|  | override auto-detection and force activation of the specified panel. | 
|  |  | 
|  | 4. Building | 
|  | ------------ | 
|  |  | 
|  | To build U-Boot for one of the Nitrogen6x or SabreLite board: | 
|  |  | 
|  | make nitrogen6x_config | 
|  | make | 
|  |  | 
|  | Note that 'nitrogen6x' is a placeholder. The complete list of supported | 
|  | board configurations is shown in the boards.cfg file: | 
|  | nitrogen6q		i.MX6Q/6D	1GB | 
|  | nitrogen6dl		i.MX6DL		1GB | 
|  | nitrogen6s		i.MX6S		512MB | 
|  | nitrogen6q2g    	i.MX6Q/6D	2GB | 
|  | nitrogen6dl2g		i.MX6DL		2GB | 
|  | nitrogen6s1g		i.MX6S		1GB | 
|  |  | 
|  | The -6q variants support either the i.MX6Quad or i.MX6Dual processors | 
|  | and are configured for a 64-bit memory bus at 1066 MHz. | 
|  |  | 
|  | The -6dl variants also use a 64-bit memory bus, operated at 800MHz. | 
|  |  | 
|  | The -6s variants use a 32-bit memory bus at 800MHz. | 
|  |  | 
|  | If you place the u-boot.imx into a single-partition SD card | 
|  | along with a binary version of the boot script 6x_upgrade.txt, | 
|  | you can program it using 'upgradeu': | 
|  |  | 
|  | U-Boot> run upgradeu |