Created attachment 1089428 [details] Output from serial port after upgrade to Fedora 23 on Beagle Bone Black Description of problem: I just upgraded to Fedora 23 on a "Beagle bone black" The kernel panics because : VFS: Cannot open root device "UUID=e098e36f-f409-44cb-9d8e-9d5c0e2ed9c9" or unknown-block(0,0): error -6 Version-Release number of selected component (if applicable): kernel-core-4.2.3-300.fc23.armv7hl How reproducible: Every time Steps to Reproduce: 1. Try to boot the machine 2. Kernel panic Actual results: [ 1.538065] VFS: Cannot open root device "UUID=e098e36f-f409-44cb-9d8e-9d5c0e2ed9c9" or unknown-block(0,0): error -6 [ 1.549173] Please append a correct "root=" boot option; here are the available partitions: [ 1.557965] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) Expected results: Booted kernel Additional info: Another odd thing : I booted an older kernel and did : dnf erase kernel-core-4.2.3-300.fc23.armv7hl dnf upgrade which reinstalled the kernel, but then when I tried to boot, u-boot said : ** Unable to read file /dtb-4.2.3-300.fc23.armv7hl/am335x-boneblack.dtb ** ... because the DTB directory got installed the wrong place : /boot/dtb-4.2.3-300.fc23.armv7hl/dtb/am335x-boneblack.dtb Notice the extra "/dtb/" in the path. When I fixed this DTB problem, I still got the kernel panic.
I noticed 2 strange things on the console : omap_i2c 44e0b000.i2c: could not find pctldev for node /ocp/l4_wkup@44c00000/scm@210000/pinmux@800/pinmux_i2c0_pins, deferring probe omap_i2c 4819c000.i2c: could not find pctldev for node /ocp/l4_wkup@44c00000/scm@210000/pinmux@800/pinmux_i2c2_pins, deferring probe ... and : Initramfs unpacking failed: junk in compressed archive Oh... now I noticed that there were a bunch of error messages during the system-upgrade process, such as : mmcqd/0: page allocation failure: order:3, mode:0xc020 omap_hsmmc 48060000.mmc: MMC start dma failure mmcblk0: unknown error -1 sending read/write command, card status 0x900 blk_update_request: I/O error, dev mmcblk0, sector 2693616 Buffer I/O error on device mmcblk0p3, logical block 165694 ... so maybe I didn't get a clean system-upgrade.
As you say, your upgrade seems to have failed. The panic is because the kernel cannot find the rootfs. That is likely because the initramfs contains the necessary functionality to find the rootfs, but since it is not valid it doesn't work. This isn't really a kernel problem.
Ohoh .... I plugged this SD card into another system, and gots lots of errors : [ 286.793487] mmc0: Got data interrupt 0x00200000 even though no data operation was in progress. [ 286.797436] mmcblk0: error -84 transferring data, sector 0, nr 8, cmd response 0x900, card status 0xb00 ... so I'll close this bug.