flashing u-boot into image start sectors

hypriot / image-builder-odroid-c1

Build SD card image for ODROID C1 and C1+

http://blog.hypriot.com/post/how-to-get-docker-working-on-your-favourite-arm-board-with-hypriotos/

MIT License

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flashing u-boot into image start sectors #4

Closed DieterReuter closed 8 years ago

DieterReuter commented 8 years ago

Since we installed the ODROID kernel in a chroot env, the u-boot isn't flashed into the SD image sectors. This has to be done as soon as we have the image file created, but can be also done as the very last step as well.

One example how to do this can be found here https://github.com/archlinuxarm/PKGBUILDs/blob/master/alarm/uboot-odroid-c1/uboot-odroid-c1.install.

djmaze commented 8 years ago

Not only that, but I am quite sure the first (boot) partition has to be a FAT32 one. So we need to have two partitions. I am currently trying to get this working.

DieterReuter commented 8 years ago

Maybe we should check the disk partition layout of an ODROID Ubuntu image. I already checked the ArchLinuxARM layout and this just uses a single EXT4 partition only.

djmaze commented 8 years ago

Ah, you're right (and I forgot). It should work with a single EXT4 partition as well.

DieterReuter commented 8 years ago

We are also thinking about using a small FAT32 partition of 64M on all devices. This is the default for the Raspi and we are able to use this partition for additional configuration files and maybe a Readme and some other stuff. Then it's easier to handle the different device images and flashing is more convenient.

DieterReuter commented 8 years ago

I just checked an Ubuntu image for C1:

fdisk -l ubuntu-14.04.3lts-lubuntu-odroid-c1-20151020.img

Disk ubuntu-14.04.3lts-lubuntu-odroid-c1-20151020.img: 5505 MB, 5505024000 bytes
4 heads, 16 sectors/track, 168000 cylinders, total 10752000 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000cde21

                                           Device Boot      Start         End      Blocks   Id  System
ubuntu-14.04.3lts-lubuntu-odroid-c1-20151020.img1            3072      266239      131584    6  FAT16
ubuntu-14.04.3lts-lubuntu-odroid-c1-20151020.img2          266240    10751999     5242880   83  Linux

DieterReuter commented 8 years ago

And here is another Ubuntu image for XU3 with a different partition layout:

fdisk -l ubuntu-14.04lts-server-odroid-xu3-20150725.img

Disk ubuntu-14.04lts-server-odroid-xu3-20150725.img: 3384 MB, 3384803328 bytes
255 heads, 63 sectors/track, 411 cylinders, total 6610944 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003f9f7

                                         Device Boot      Start         End      Blocks   Id  System
ubuntu-14.04lts-server-odroid-xu3-20150725.img1            4096      208895      102400    c  W95 FAT32 (LBA)
ubuntu-14.04lts-server-odroid-xu3-20150725.img2          208896     6610943     3201024   83  Linux

umiddelb commented 8 years ago

There is no strict technical requirement for loading the kernel image, device tree, boot script, etc. from a fat partition since most u-boot implementations support ext2load (which is sufficient to load a file from an ext4 partition). The necessity for a fat partition only relates to the level of compatibility you want to retain (some people prefer to change the boot settings with the help of their Windows or Mac computer). I personally prefer a single ext4 partition layout which makes it easier to have several co-existing OS installed on the same media without interfering each other. But this may break compatibility to existing tools and processes, see here.

umiddelb commented 8 years ago

I'm about to consolidate the various ways how u-boot is used among different ARM boards, I hope I'll publish this work soon.