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![]() Convert pcm058 support to use device trees and the driver model. Add rudimentary boot scripts to the environment, expand README. Signed-off-by: Niel Fourie <lusus@denx.de> Cc: Stefano Babic <sbabic@denx.de> |
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Kconfig | ||
MAINTAINERS | ||
Makefile | ||
pcm058.c | ||
README |
Board information ----------------- The SBC produced by Phytec has a SOM based on a i.MX6Q. The SOM is sold in two versions, with eMMC or with NAND. Support here is for the SOM with NAND. The evaluation board "phyBoard-Mira" is thought to be used together with the SOM. More information on the board can be found on manufacturer's website: http://www.phytec.de/produkt/single-board-computer/phyboard-mira/ http://www.phytec.de/fileadmin/user_upload/images/content/1.Products/SOMs/phyCORE-i.MX6/L-808e_1.pdf Building U-Boot ------------------------------- $ make pcm058_defconfig $ make This generates the artifacts SPL and u-boot.img. The SOM can boot from NAND or from SD-Card, having the SPI-NOR as second option. The dip switch "DIP-1" on the board let choose between NAND and SD. DIP-1 set to off: Boot first from NAND, then try SPI DIP-1 set to on: Boot first from SD, then try SPI The bootloader was tested with DIP-1 set to on. If a SD-card is present, then the RBL tries to load SPL from the SD Card, if not, RBL loads from SPI-NOR. The SPL tries then to load from the same device where SPL was loaded (SD or SPI). Booting from NAND is not supported. Flashing U-Boot onto an SD card ------------------------------- After a successful build, the generated SPL and U-boot binaries can be copied to an SD card. Adjust the SD card device as necessary: $ sudo dd if=u-boot-with-spl.imx of=/dev/mmcblk0 bs=1k seek=1 This is equivalent to separately copying the SPL and U-boot using: $ sudo dd if=SPL of=/dev/mmcblk0 bs=1k seek=1 $ sudo dd if=u-boot-dtb.img of=/dev/mmcblk0 bs=1k seek=197 The default bootscripts expect a kernel fit-image file named "fitImage" in the first partition and Linux ext4 rootfs in the second partition. Flashing U-boot to the SPI Flash, for booting Linux from NAND ------------------------------------------------------------- The SD card created above can also be used to install the SPL and U-boot into the SPI flash. Boot U-boot from the SD card as above, and stop at the autoboot. Then, clear the SPI flash: => sf probe => sf erase 0x0 0x1000000 Load the SPL from raw MMC into memory and copy to the SPI. The SPL is maximum 392*512-byte blocks in size therefore 0x188 blocks, totaling 0x31000 bytes: => mmc read ${loadaddr} 0x2 0x188 => sf write ${loadaddr} 0x400 0x31000 Load the U-boot binary into memory and copy to the SPI. U-boot should fit into 640KiB, so 0x500 512-byte blocks, totalling 0xA0000 bytes: => mmc read ${loadaddr} 0x18a 0x500 => sf write ${loadaddr} 0x40000 0xA0000 The default NAND bootscripts expect a single MTD partition named "rootfs", which in turn contains the UBI volumes "fit" (which contains the kernel fit- image) and "root" (which contains a ubifs root filesystem). The "bootm_size" variable in the environment -------------------------------------------- By default, U-boot relocates the device tree towards the upper end of the RAM, which kernels using CONFIG_HIGHMEM=y may not be able to access during early boot. With the bootm_size variable set to 0x30000000, U-boot relocates the device tree to below this address instead.