1How to use and build U-Boot on mx6sabreauto 2------------------------------------------- 3 4mx6sabreauto_defconfig target supports mx6q/mx6dl/mx6qp sabreauto variants. 5 6In order to build it: 7 8$ make mx6sabreauto_defconfig 9 10$ make 11 12This will generate the SPL and u-boot.img binaries. 13 14- Flash the SPL binary into the SD card: 15 16$ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 && sync 17 18- Flash the u-boot.img binary into the SD card: 19 20$ sudo dd if=u-boot.img of=/dev/sdX bs=1K seek=69 && sync 21 22Booting via Falcon mode 23----------------------- 24 25Write in mx6sabreauto_defconfig the following define below: 26 27CONFIG_SPL_OS_BOOT=y 28 29In order to build it: 30 31$ make mx6sabreauto_defconfig 32 33$ make 34 35This will generate the SPL image called SPL and the u-boot.img. 36 37- Flash the SPL image into the SD card: 38 39$ sudo dd if=SPL of=/dev/sdb bs=1K seek=1 && sync 40 41- Flash the u-boot.img image into the SD card: 42 43$ sudo dd if=u-boot.img of=/dev/sdb bs=1K seek=69 && sync 44 45Create a FAT16 boot partition to store uImage and the dtb file, then copy the files there: 46 47$ sudo cp uImage /media/boot 48 49$ sudo cp imx6dl-sabreauto.dtb /media/boot 50 51Create a partition for root file system and extract it there: 52 53$ sudo tar xvf rootfs.tar.gz -C /media/root 54 55The SD card must have enough space for raw "args" and "kernel". 56To configure Falcon mode for the first time, on U-Boot do the following commands: 57 58- Load dtb file from boot partition: 59 60# load mmc 0:1 ${fdt_addr} imx6dl-sabreauto.dtb 61 62- Load kernel image from boot partition: 63 64# load mmc 0:1 ${loadaddr} uImage 65 66- Write kernel at 2MB offset: 67 68# mmc write ${loadaddr} 0x1000 0x4000 69 70- Setup kernel bootargs: 71 72# setenv bootargs "console=ttymxc3,115200 root=/dev/mmcblk0p1 rootfstype=ext4 rootwait quiet rw" 73 74- Prepare args: 75 76# spl export fdt ${loadaddr} - ${fdt_addr} 77 78- Write args 1MB data (0x800 sectors) to 1MB offset (0x800 sectors) 79 80# mmc write 18000000 0x800 0x800 81 82- Restart the board and then SPL binary will launch the kernel directly. 83