| U-Boot for the Gateworks Ventana Product Family boards |
| |
| This file contains information for the port of U-Boot to the Gateworks |
| Ventana Product family boards. |
| |
| 1. Boot source, boot from NAND |
| ------------------------------ |
| |
| The i.MX6 BOOT ROM expects some structures that provide details of NAND layout |
| and bad block information (referred to as 'bootstreams') which are replicated |
| multiple times in NAND. The number of replications is configurable through |
| board strapping options and eFUSE settings. The Freescale 'kobs-ng' |
| application from the Freescale LTIB BSP, which runs under Linux, must be used |
| to program the bootstream in order to setup the replicated headers correctly. |
| |
| The Gateworks Ventana boards with NAND flash have been factory programmed |
| such that their eFUSE settings expect 2 copies of the boostream (this is |
| specified by providing kobs-ng with the --search_exponent=1 argument). Once in |
| Linux with MTD support for the NAND on /dev/mtd0 you can program the boostream |
| with: |
| |
| kobs-ng init -v -x --search_exponent=1 u-boot.imx |
| |
| The kobs-ng application uses an imximage (u-boot.imx) which contains the |
| Image Vector Table (IVT) and Device Configuration Data (DCD) structures that |
| the i.MX6 BOOT ROM requires to boot. The kobs-ng adds the Firmware |
| Configuration Block (FCB) and Discovered Bad Block Table (DBBT). |
| |
| This information is taken from: |
| http://trac.gateworks.com/wiki/ventana/bootloader#NANDFLASH |
| |
| More details about the i.MX6 BOOT ROM can be found in the IMX6 reference manual. |
| |
| 2. Build |
| -------- |
| |
| There are several Gateworks Ventana boards that share a simliar design but |
| vary based on CPU, Memory configuration, and subloaded devices. Although |
| the subloaded devices are handled dynamically in the bootloader using |
| factory configured EEPROM data to modify the device-tree, the CPU choice |
| (IMX6Q vs IMX6DL) and memory configurations are currently compile-time |
| options. |
| |
| The following Gateworks Ventana configurations exist: |
| gwventanaq1gspi: MX6Q,1GB,SPI FLASH |
| gwventanaq : MX6Q,512MB,NAND FLASH |
| gwventanaq1g : MX6Q,1GB,NAND FLASH |
| gwventanadl : MX6DL,512MB,NAND FLASH |
| gwventanadl1g : MX6DL,1GB,NAND FLASH |
| |
| To build U-Boot for the MX6Q,1GB,NAND FLASH for example: |
| |
| make gwventanaq1g_config |
| make |
| |
