"officially" supported kernel is branch 3.14-1.0.x-mx6-sr from solidrun (3.14.60 at the time of writing)
unofficial kernel is branch imx6-4.4.y from xbian thanks to mk01 (4.4.6+rt3)
patches can be in subfolder: projects/imx6/patches/linux/3.14-mx6-sr/
kernel config can be in subfolder: projects/imx6/linux/3.14-mx6-sr/linux.arm.conf
needs double space on storage partition for extracted .img file
KERNEL/SYSTEM files are copied directly from mounted partition to /flash
tested on imx6 project
size of initramfs/kernel increased by ~40kB
if downgrade with image without included .md5 files
user needs to create file .nocheck (there is no integrity
checks done in this case - can be unsafe)
### Checking for updates ###
Found new .tar archive. extracting...
Checking KERNEL.md5...
/storage/.update/KERNEL: OK
Checking SYSTEM.md5...
/storage/.update/SYSTEM: OK
Checking size: OK
### mount filesystem /flash/SYSTEM ... ###
### mount filesystem /storage/.update/SYSTEM ... ###
updating Kernel...
updating System...
### mount filesystem /flash/SYSTEM ... ###
updating Bootloader...
*** updating Device Tree Blob: imx6q-udoo.dtb ...
.................................................
*** updating u-boot image: /flash/u-boot.img ...
*** updating u-boot SPL Blob on: /dev/mmcblk0 ...
35+0 records in
35+0 records out
35840 bytes (35.0KB) copied, 0.050510 seconds, 692.9KB/s
System reboots now...
### Checking for updates ###
Found new .img.gz archive. extracting...
Mounting system partition...
Checking KERNEL.md5...
/storage/.update/.tmp/mnt/KERNEL: OK
Checking SYSTEM.md5...
/storage/.update/.tmp/mnt/SYSTEM: OK
Checking size: OK
updating Kernel...
updating System...
### mount filesystem /flash/SYSTEM ... ###
updating Bootloader...
*** updating Device Tree Blob: imx6dl-cubox-i.dtb ...
.....................................................
*** updating u-boot image: /flash/u-boot.img ...
*** updating u-boot SPL Blob on: /dev/mmcblk0 ...
35+0 records in
35+0 records out
35840 bytes (35.0KB) copied, 0.050320 seconds, 695.5KB/s
System reboots now...
### Checking for updates ###
Found new .img file...
Mounting system partition...
Checking KERNEL.md5...
/storage/.update/.tmp/mnt/KERNEL: OK
Checking SYSTEM.md5...
/storage/.update/.tmp/mnt/SYSTEM: OK
Checking size: OK
updating Kernel...
updating System...
### mount filesystem /flash/SYSTEM ... ###
updating Bootloader...
*** updating Device Tree Blob: imx6dl-cubox-i.dtb ...
.....................................................
*** updating u-boot image: /flash/u-boot.img ...
*** updating u-boot SPL Blob on: /dev/mmcblk0 ...
35+0 records in
35+0 records out
35840 bytes (35.0KB) copied, 0.050320 seconds, 695.5KB/s
System reboots now...
Mtools is used to format and copy files to vfat partition.
Populatefs is used to copy files to ext4 partition.
Tested on imx6 with u-boot, Generic with BIOS and EFI boot.
To avoid messing around with ext4 partition we could also provide "empty" disk image file. Both partitions would be already formatted and storage partition would already contain resize file. Then mkimage script would only copy kernel, system, bootloader files and install bootloader.
But current approach is more flexible for future use.
