Re: [fedora-arm] Compiled kernel problem

On 17 August 2014 11:55:40 GMT+08:00, "Iván Chavero" <ichavero(a)chavero.com.mx&gt; wrote: There's no point building your own 3.4 kernel when Fedora already did it from upstream sources. Even if you want missing pieces like video, you can still get everything else up and prove the flow using their image and then video is your only problem, instead of "nothing works" being your problem. There seem to be a few gotchas with the otherwise excellent Allwinner A20 stuff. Download a Fedora xz SD Card image and xzcat it on to an sd Card, eg, /dev/sdv since the image contains a partition table already. This one worked for me (get the xz image link at the end) http://koji.fedoraproject.org/koji/taskinfo?taskID=7272114 Now the quirks... 1) The Rom in the A20 expects the SD card to have a U-Boot binary stashed at +16 512-byte sectors on the card. Build the magic A20-specific U-Boot as mentioned by Robert a few days ago on this list and dd it into place on your card. https://lists.fedoraproject.org/pipermail/arm/2014-August/008150.html 2) The U-Boot binaries keep an environment stored elsewhere on the SD card... I dunno where. If you're re-using an existing SD card that already had an image on it, you'll need to use the U-Boot commands to force the environment to be reset and then save it before it will use the new default environment from the new U-Boot and act reasonably. Otherwise your new, improved U-Boot will load the old craptastic environment and do nothing useful. (In fact this whole environment thing has always been an unmaintainable mess in U-Boot, it's a step forward that this new method requires the default env to work properly... just nuke the env and leave it at default). Once you took care of that, the default env and the stuff placed into /boot by the xz image are enough to figure out where the dtb is down the versioned dtb dir, so there is nothing special you need to do about that, it will know the kernel version string from what the Fedora image did and go to the right dir itself and stick it somewhere reasonable in DDR at boot time. So it's almost enough already.... 3) Set up a serial console. The new bootloader scripts default to looking in [/boot/]extlinux/extlinux.conf to find out what to do For Cubieboard 2, this has to be edited to change the "append" line for the kernel to add console=ttyS0,115200 then with a USB serial adapter on the 4-pin connector, you should boot and see a firstboot script there. Currently it's not very turnkey and you have to know the above quirks. But I found the results are VERY good, Fedora + Cubieboard 2 is very solid 2 x A7 system with decent DDR + SD rootfs, and worth the small effort needed currently to make it work. -Andy