Installing Arch Linux on Hobbitboard Poslab

[summers]

OK the relevant stuff is:

$this->bbcode_second_pass_code('', '[ 3030.723089] usb 2-1.1: USB disconnect, device number 11
[ 3038.181133] usb 2-1.1: new high-speed USB device number 12 using ehci-pci
[ 3038.274846] usb 2-1.1: New USB device found, idVendor=15a2, idProduct=0054
[ 3038.274856] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 3038.274861] usb 2-1.1: Product: SE Blank ARIK
[ 3038.274865] usb 2-1.1: Manufacturer: Freescale SemiConductor Inc
[ 3038.277720] hid-generic 0003:15A2:0054.0008: hiddev0,hidraw0: USB HID v1.10 Device [Freescale SemiConductor Inc SE Blank ARIK] on usb-0000:00:1d.0-1.1/input0
[ 4657.071710] usb 2-1.1: USB disconnect, device number 12
[ 4667.247083] usb 2-1.1: new high-speed USB device number 13 using ehci-pci
[ 4667.339820] usb 2-1.1: New USB device found, idVendor=15a2, idProduct=0054
[ 4667.339824] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 4667.339826] usb 2-1.1: Product: SE Blank ARIK
[ 4667.339828] usb 2-1.1: Manufacturer: Freescale SemiConductor Inc
[ 4667.341725] hid-generic 0003:15A2:0054.0009: hiddev0,hidraw0: USB HID v1.10 Device [Freescale SemiConductor Inc SE Blank ARIK] on usb-0000:00:1d.0-1.1/input0
[ 4677.290671] usb 2-1.1: USB disconnect, device number 13
[ 4677.488004] usb 2-1.1: new high-speed USB device number 14 using ehci-pci
[ 4677.581445] usb 2-1.1: New USB device found, idVendor=15a2, idProduct=0054
[ 4677.581455] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 4677.581461] usb 2-1.1: Product: SE Blank ARIK
[ 4677.581465] usb 2-1.1: Manufacturer: Freescale SemiConductor Inc
[ 4677.586262] hid-generic 0003:15A2:0054.000A: hiddev0,hidraw0: USB HID v1.10 Device [Freescale SemiConductor Inc SE Blank ARIK] on usb-0000:00:1d.0-1.1/input0')

So we see it coming up in serial mode when it enumerates as 15a2, then it detaches - which is probably what happened after bootbomb started running. But when it comes back again it is still in 15a2 mode, so looks like it is still in serial boot mode.

[summers]

Ah:

https://www.nxp.com/docs/en/user-guide/PICO-IMX6UL-USG.pdf

suggests that bootbomb comes from:

http://www.hobbitboard.org/downloads/hobbit/

Which is the original manufacturer - so it was something they distributed ...

And interestingly the schematic of the original is available. https://www.nxp.com/downloads/en/schematics/HOBBIT6UL-BB-SCH.pdf - it it was available for the new one, we could see what is wired where, and so learn what the jumpers do ...

Reflecting on what has been learnt. There are two boards "Wanboard Hobbitboard" and "Poslab Hobbitboard", they layout of the two is clearly different. It seems probable that the schematic for important bits, like the eMMC, are different. But they both have the same processor - and so are related.

Both can be made to boot over usb serial, all be it in different ways - this is a function of the processor ROM.

Now bootbomb was developed by Wanboard - the manufacture of one of the boards. It works on the Wanbaord board, but doesn't seem to work on the Poslab board - but the serial load seems to work.

Now the workings of bootbomb - we can see it contains a uboot near the beginning, this then probably boots the bootbomb which exports the eMMC over the usb link. Now why this doesn't work on poslab, we can't say, it could be the eMMC is on different pins.

So the question should be asked, how close are the boards. When the poslab board boots does it use the same device tree? It is different enough in hardware it seems probable its separate - in which case it should be examined to find how the board has been wired.

Now how would we want to install an OS onto the poslab eMMC. Obvious thing to do would be to across the serial usb link, to load a minimal OS, that gives access to the hardware. Obviously is a linux kernel, where the initramdisk contains enough to bring up the system- e.g. brings up the newtork, allows login, has wget and bsdtar, so arch can be downloaded and installed.

This sounds alot of work, but actually think its what moonman did with the rescue partition on the NSA325 device. Actually looking into moonman's rescure disk - it looks close to a full arch install. For an initramdisk file system, my guess is simple busybox + musl + dropbear + wget + bsdtar would be enough ...

Its also very close to what bootbomb does, e.g. the booting via uboot would be common.

Hassle is how to develop the code, would almost certainly need access to the UART on the board - just for debugging. Developing an OS without debugging is hard, I managed it on a Pocket Beagle, but only because I could test on a BeagleBoneBlack - thats the same hardware, in a different format.

So think this gives you what you need to decide if you move forward. Do you have a UART connector (like the FTDI RPi cable)? Do you know where the UART pins are on the Hobbitboard? Are you willing to spend some time debugging the set up?

If you want to learn about developing these little small embedded systems, its not a bad way to learn. But it does need the commitment, and thats the rub ...

I guess as the board has an RS232 DB9 mounted that the default UART will be on that, and at the 5V level (RS232 standard).

[coolHacker]

I'm afraid that the image file is not working. It's archlinux.tgz with size around 300MB. Do you know where to get the image file?