This file contains information for the port of U-Boot to the Gateworks
Ventana Product family boards.
-1. Boot source, boot from NAND
+1. Secondary Program Loader (SPL)
+---------------------------------
+
+The i.MX6 has a BOOT ROM PPL (Primary Program Loader) which supports loading
+an executable image from various boot devices.
+
+The Gateworks Ventana board config uses an SPL build configuration. This
+will build the following artifacts from u-boot source:
+ - SPL - Secondary Program Loader that the i.MX6 BOOT ROM (Primary Program
+ Loader) boots. This detects CPU/DRAM configuration, configures
+ The DRAM controller, loads u-boot.img from the detected boot device,
+ and jumps to it. As this is booted from the PPL, it has an IVT/DCD
+ table.
+ - u-boot.img - The main u-boot core which is u-boot.bin with a image header.
+
+
+2. Build
+--------
+
+To build U-Boot for the Gateworks Ventana product family:
+
+ make gwventana_config
+ make
+
+
+3. 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.
+multiple times in NAND. The number of replications and their spacing (referred
+to as search stride) is configurable through board strapping options and/or
+eFUSE settings (BOOT_SEARCH_COUNT / Pages in block from BOOT_CFG2). In
+addition, the i.MX6 BOOT ROM Flash Configuration Block (FCB) supports two
+copies of a bootloader in flash in the case that a bad block has corrupted one.
+The Freescale 'kobs-ng' application from the Freescale LTIB BSP, which runs
+under Linux and operates on an MTD partition, must be used to program the
+bootstream in order to setup this flash structure 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
+Linux with MTD support for the NAND on /dev/mtd0 you can program the SPL
with:
-kobs-ng init -v -x --search_exponent=1 u-boot.imx
+kobs-ng init -v -x --search_exponent=1 SPL
-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).
+The kobs-ng application uses an imximage 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). The SPL build artifact from u-boot is
+an imximage.
-This information is taken from:
- http://trac.gateworks.com/wiki/ventana/bootloader#NANDFLASH
+The u-boot.img, which is the non SPL u-boot binary appended to a u-boot image
+header must be programmed in the NAND flash boot device at an offset hard
+coded in the SPL. For the Ventana boards, this has been chosen to be 14MB.
+The image can be programmed from either u-boot or Linux:
-More details about the i.MX6 BOOT ROM can be found in the IMX6 reference manual.
-
-2. Build
---------
+u-boot:
+Ventana > setenv mtdparts mtdparts=nand:14m(spl),2m(uboot),1m(env),-(rootfs)
+Ventana > tftp ${loadaddr} u-boot.img && nand erase.part uboot && \
+ nand write ${loadaddr} uboot ${filesize}
-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.
+Linux:
+nandwrite /dev/mtd1 u-boot.img
-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
+The above assumes the default Ventana partitioning scheme which is configured
+via the mtdparts env var:
+ - spl: 14MB
+ - uboot: 2M
+ - env: 1M
+ - rootfs: the rest
-To build U-Boot for the MX6Q,1GB,NAND FLASH for example:
+This information is taken from:
+ http://trac.gateworks.com/wiki/ventana/bootloader#NANDFLASH
- make gwventanaq1g_config
- make
+More details about the i.MX6 BOOT ROM can be found in the IMX6 reference manual.
projects / karo-tx-uboot.git / blobdiff