[meta-xilinx] Kernel (linux-xlnx) hangs when trying to mount root (SD card & NFS)

[Kleve, Jesse R]

I’m trying to get my petalinux dom0 kernel to mount my rootfs on top of Xen. I’m running on the zcu102. The issue I’m having is that the boot hangs at mounting the rootfs. I’ve tried setting the rootfs to my second partition on my SD card as well as a NFS mount.

I think I’ve ruled out it being an issue with my SD card since I’ve been trying NFS too. Also, I can get the SD card to mount as the rootfs if I run my kernel bare-metal without Xen. Because of this, I don’t think this post will help me but I could be wrong.
https://forums.xilinx.com/t5/Embedded-Linux/Xilinx-Linux-does-not-detect-SD-card-on-boot/m-p/504439#M10196

SD card bootargs
console=hvc0 earlycon=xen earlyprintk=xen root=/dev/mmcblk0p2 rw clk_ignore_unused

NFS bootargs
console=hvc0 earlycon=xen earlyprintk=xen root=/dev/nfs nfsroot=<server>:<dir> ip=dhcp rw clk_ignore_unused

I’m using the Xilinx/petalinux repos (rel-v2018.2) with the following user defined settings in local.conf
MACHINE = “zcu102-zynqmp”
DISTRO = “petalinux”
DISTRO_FEATURES += “x11 virtualization xen”

Any suggestions would be greatly appreciated.

[    3.351326] VFS: Cannot open root device "mmcblk0p2" or unknown-block(0,0): error -6
[    3.358582] Please append a correct "root=" boot option; here are the available partitions:
[    3.366968] 0100           65536 ram0
[    3.366970]  (driver?)
[    3.373188] 0101           65536 ram1
[    3.373189]  (driver?)
[    3.379422] 0102           65536 ram2
[    3.379423]  (driver?)
[    3.385652] 0103           65536 ram3
[    3.385653]  (driver?)
[    3.391873] 0104           65536 ram4
[    3.391875]  (driver?)
[    3.398109] 0105           65536 ram5
[    3.398111]  (driver?)
[    3.404331] 0106           65536 ram6
[    3.404332]  (driver?)
[    3.410565] 0107           65536 ram7
[    3.410566]  (driver?)
[    3.416788] 0108           65536 ram8
[    3.416789]  (driver?)
[    3.423022] 0109           65536 ram9
[    3.423023]  (driver?)
[    3.429245] 010a           65536 ram10
[    3.429247]  (driver?)
[    3.435567] 010b           65536 ram11
[    3.435569]  (driver?)
[    3.441883] 010c           65536 ram12
[    3.441884]  (driver?)
[    3.448191] 010d           65536 ram13
[    3.448192]  (driver?)
[    3.454511] 010e           65536 ram14
[    3.454512]  (driver?)
[    3.460821] 010f           65536 ram15
[    3.460823]  (driver?)
[    3.467142] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[    3.475442] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-xilinx-v2018.2 #2
[    3.482705] Hardware name: ZynqMP ZCU102 Xen (DT)
[    3.487463] Call trace:
[    3.489981] [<ffffff8008088c58>] dump_backtrace+0x0/0x368
[    3.495425] [<ffffff8008088fd4>] show_stack+0x14/0x20
[    3.500531] [<ffffff8008a0caf8>] dump_stack+0x9c/0xbc
[    3.505634] [<ffffff800809bdc0>] panic+0x11c/0x274
[    3.510478] [<ffffff8008d41124>] mount_block_root+0x1a8/0x27c
[    3.516272] [<ffffff8008d41430>] mount_root+0x11c/0x134
[    3.521549] [<ffffff8008d415b4>] prepare_namespace+0x16c/0x1b4
[    3.527432] [<ffffff8008d40d44>] kernel_init_freeable+0x1b8/0x1d8
[    3.533575] [<ffffff8008a1ee48>] kernel_init+0x10/0x100
[    3.538852] [<ffffff8008084a90>] ret_from_fork+0x10/0x18
[    3.544215] Kernel Offset: disabled
[    3.547761] CPU features: 0x002004
[    3.551220] Memory Limit: none
[    3.554338] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)