mattkosem

Neat, can I expect that uboot will load that file during boot like the Libre image does from it's vfat partition? --Matt

Well, it's not Armbian, but I am able to make the official Libre 16.04 image boot and run from just the EMMC card with a simple tweak. Basically I created a boot.txt file with this content setenv bootargs console=ttyAML0 root=/dev/mmcblk0p2 rootfstype=btrfs rootflags=subvol=@ rootwait console=ttyAML0,115200 no_console_suspend fatload ${devtype} ${devnum} $fdt_addr_r $fdtfile fatload ${devtype} ${devnum} $kernel_addr_r Image booti $kernel_addr_r - $fdt_addr_r Then ran this command to make a new boot.scr: mkimage -A arm -T script -O linux -d boot.txt boot.scr I dropped the resulting new boot.scr in place of the original in the first partition on the card, and presto...it boots. I did some tinkering in between (manually expanding the root partition and making a swap partition) that I'm not sure if is really important over the course of troubleshooting. Not sure if that is/isn't actually a necessary thing to do. Making the same basic change with a hex editor to the existing boot.scr didn't yield an identical file, so I have to assume some checksum that tool makes is the difference there. I see a boot.scr in the Le Potatio Armbian image as well, which it may be possible to similarly replace with contents stripped from that file compiled with mkimage, but haven't had an opportunity to try that yet. --Matt

Hardkernel's "selfinstall" images for Android seem to have a purpose-build solution for this sort of flashing (which they use for their Android images): https://github.com/codewalkerster/android_device_hardkernel_odroidc2/blob/s905_5.1.1_master/selfinstall.mk At this point, I'm grasping at enough straws that I'll give it a look when I next have a moment. --Matt

Those boot0 and boot1 partitions don't seem to be writable by default. I can see their contents though. Anyone know anything about a"ddbr" tool? I see it mentioned in reference to writing bootloader files to Amlogic boards, but can't find much about it.

I came across this too, but it seems to be centered around using a writer adapter. https://wiki.odroid.com/odroid-c2/software/building_u-boot. The script in that tarball dds the bootloader and uboot to certain spots on the device. --Matt

Well, that USB flash stuff seems to rely upon starting with an Amlogic-layout Android image. Even the Libre Android image doesn't seem to be in that format, so I'm not sure its viable. --Matt

Neat, I'll take a peek at that when I have a moment. These are some other locations that seem like they may have helpful resources: http://docs.khadas.com/social/BuildBootloaderAndRamfs/ https://forum.odroid.com/viewtopic.php?f=138&t=20869&p=180545&hilit=booting+alternate+kernels#p149212 http://www.denx.de/wiki/DULG/UBootScripts Maybe tftp is the way to get that stuff loaded... --Matt

Yeah, that's uncharted territory for me as well. I'm used to having a vfat /boot partition on SBCs. Mine shows up as even more than that: brw-rw---- 1 root disk 179, 0 Jan 26 03:22 mmcblk0 brw-rw---- 1 root disk 179, 32 Jan 26 02:47 mmcblk0boot0 brw-rw---- 1 root disk 179, 64 Jan 26 02:47 mmcblk0boot1 brw-rw---- 1 root disk 179, 1 Jan 26 02:47 mmcblk0p1 brw-rw---- 1 root disk 179, 96 Jan 26 02:47 mmcblk0rpmb This is at least roughly consistent with the layout I've seen on other boards. The only experience I have with flashing an emmc module directly on an SBC involves Android images on Hardkernel boards (this sort of processhttps://odroidinc.com/blogs/news/how-to-upgrade-the-odroid-xu4-android-emmc-module-to-the-latest-os-version), and was automated :X. It would be nice if these cards could be snapped into an adapter like Hardkernel provides for ODROID devices to accomplish tasks like this. mmcblk0boot0 and mmcblk0boot1 both appear to storage areas be 4MB, and writable. I guess I could try writing this u-boot image to one or both of them. Any chance you've got some handy docs making sense of those devices? I came across this, but haven't had a chance to read far into it yet: http://forum.khadas.com/t/emmc-flash-layout/133 --Matt

I built the u-boot bin files as per the instructions, but didn't really get as far as I'd have hoped afterwards. One tip I have along the way for building is that the call to that pyc file needs to be preceded by "python " for it to actually work. Some notes on what I did find: 1. After dding the uboot bin file to /dev/mmcblk0, there was no longer a partition table (are the instructions wrong here? Should this actually be one of those *boot* devices on mmcblk0?) 2. It doesn't seem possible to create a vfat partition like those instructions say. 100 isn't a usable starting offset, 300 blocks is way too little space, etc. I ended up creating a 256MB vfat partition there, copying kernel/initrd files and a boot.env file ready to boot to an existing working root from it, but it didn't really seem to work. I get a solid red and blue and the device won't boot with the emmc card attached after going through that. All in all, I've got the files...just need to spend some more time determining how/where they get written. --Matt

Well, I started going through those instructions but couldn't run the GCC bundles on anything I have set up. They seem to be 32-bit x86 binaries, and I have only non-multilib x86_64, ARMv6, and AARCH64 systems ATM Oh well, I can set up a 32-bit VM or something when I have a moment. Between the support for both emmc and sdcard support binaries, and a patch to make configs read from/save to the disk, this sounds promising. --Matt

Aw sweet, that looks like the ticket!

The LibreELEC image was different enough to change the behavior of booting somewhat. Instead of getting skipped over entirely like the other images, that one on the eMMC makes it just not boot. @TonyMac32 - Any chance you've got some pointers on building those U-Boot sources? I'm about to shut down for tonight, but I can try to find a p212 image. --Matt

I had a chance to give the took a try on a windows laptop. The upper center USB port got me the "WorldCup Device" the tool could see, but no images I tried could get past import since they all said "Parse burning image fail". I get the impression that the LibreElec folks might have eMMC booting working. I may give that image a chance when I have a moment. --Matt

Keep us posted if you beat me to trying it. I've got a line on a windows PC to bum tomorrow, but might not have a chance to try it until Thursday. --Matt

Hey Tony, Ok, so images will have to be built for eMMC or SD based on that? Or do they end up in different spots on the device? When you say "The bootscript/etc need to point at the right device or else it will have no idea where to get the device tree/kernel/etc.", are you referring to a script at U-Boot build time or a script on the boot partition of the device? I've managed to locate a setenv line targeting the root partition and mentioning the location of the kernel image both in the boot partition, and in some space toward the beginning of the device, and modified both with a hex editor to target the eMMC device (mmcblk0) instead, but that didn't help me. Perhaps this u-boot button behind the ethernet jack is the answer. Any idea how to use it? Any googling I've done hasn't really yielded anything material on it. Would I press it before writing to the device? I have come across mention of that tool thus far, but have seen only unsuccessful attempts to use it elsewhere in relation to this board. Libre was nice enough to include a USB A-A cable with my eMMC module, so at least I don't have to make one We don't have any Windows PCs in the house, so it doesn't seem likely that that tool will be helpful over here. I'll have to think on that one or borrow a system. --Matt