I’ve been working on bringing a newer kernel to my WDMyCloud Gen1 (sequoia) device for some time and got to v3.2.101 mostly working, w/o 64K pages and netatop causing kernel panic, but it is still 3.2. I was not able to move past 3.2 with all attempts thwarted by changes in ARM GIC handling between those versions, that I could not figure how to work around.
WD does not appear to have any incentive/capabilities to upgrade the device past officially-supported Mindsped/NXP SDK versions based on kernel 3.2.
However, I was able to launch kernel 3.19.3 using mainline + patches from https://github.com/bitdefender/boxv2-firmware for comcerto2000 target (which is also known under FreeScale/NXP QorIQ LS1024A name, and the SOC is still being sold by NXP). I updated the load address to match sequoia, patched includes in board-c2kevm.c and got to rootfs initialization:
Barebox-C2K >/env/bin bootm /dev/mem.uImage
Verifying Checksum ... OK
Image Name: Linux-3.19.3test1
Created: 2019-08-28 4:40:45 UTC
Image Type: <NULL> <NULL> <NULL> (<NULL>)
Data Size: 1549632 Bytes = 1.5 MB
Load Address: 0f008000
Entry Point: 0f008000
OK
Starting kernel ...
commandline: console=ttyS0,115200n8, init=/sbin/init rootfstype=ext4 rw noinitrd mac_addr=00:11:22:33:44:55 model= serial= board_test= btn_status=0
arch_number: 1094
Uncompressing Linux... done, booting the kernel.
[ 0.000000] Booting Linux on physical CPU 0x900
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 3.19.3test1 (rye@bling) (gcc version 4.8.5 (Linaro GCC 4.8-2015.06) ) #3 SMP Wed Aug 28 04:35:38 UTC 2019
[ 0.000000] CPU: ARMv7 Processor [412fc091] revision 1 (ARMv7), cr=10c5387d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] Machine: Comcerto 2000 EVM
[ 0.000000] Memory policy: Data cache writealloc
[ 0.000000] PERCPU: Embedded 10 pages/cpu @cfdee000 s9792 r8192 d22976 u40960
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 59904
[ 0.000000] Kernel command line: console=ttyS0,115200n8, init=/sbin/init rootfstype=ext4 rw noinitrd mac_addr=00:11:22:33:44:55 model= serial= board_test= btn_status=0
...
[ 0.104076] Brought up 1 CPUs
[ 0.104105] SMP: Total of 1 processors activated (1292.69 BogoMIPS).
[ 0.104116] CPU: All CPU(s) started in SVC mode.
...
[ 4.977713] VFS: Cannot open root device "(null)" or unknown-block(0,0): error -19
[ 4.985328] Please append a correct "root=" boot option; here are the available partitions:
[ 4.993803] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 5.002121] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.19.3test1 #3
[ 5.009640] Hardware name: Comcerto 2000 EVM
[ 5.013932] Backtrace:
...
[ 5.129690] r4:00000000 r3:cf832000
[ 5.133317] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Just want this information out for somebody with enough cycles to tackle the board bringup and tailoring the patched kernel for sequoia.