[Android Software/Hacking General [Developers Only]] alexmrqt:
As a follow-up, I ran your configuration on my Manta (I only made the changes to get the serial console and added a missing fixed-clock node in the DTS that made the kernel panic in an early stage, see my fork here https://github.com/alexmrqt/manta-mainline/tree/8bf3528c1f9d9fb5eeb478901a88c495cacf5247).

With that, the device reboots after some times (but it is due to a kernel issue, as I used another ramdisk that is not supposed to do that).

See the kernel console below.

Starting kernel at 0x40008000...

AST_POWERON..
DEVICEINFO;R32D2042RBF;MANTAMF01;8;08:D4:2B:1F:C7:06;08:D4:2B:1F:C7:05;INFODONE
DTB:0x4021CC48 (0x0000A06D)
C:0x400080E0-0x40226E00->0x40682800-0x408A1520
DTB:0x40897368 (0x0000A1AB)
Uncompressing Linux... done, booting the kernel.
Booting Linux on physical CPU 0x0
Linux version 5.16.0-rc5-next-20211215 (pmos@laptop-218) (armv7-alpine-linux-musleabihf-gcc (Alpine 11.2.1_git20220219) 11.2.1 2022022
CPU: ARMv7 Processor [410fc0f4] revision 4 (ARMv7), cr=10c5387d
CPU: div instructions available: patching division code
CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache
OF: fdt: Machine model: Samsung Nexus 10 (manta)
printk: bootconsole [earlycon0] enabled
Memory policy: Data cache writealloc
Samsung CPU ID: 0x43520210
Zone ranges:
Normal [mem 0x0000000040000000-0x000000004fffffff]
HighMem empty
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000040000000-0x000000004fffffff]
Initmem setup node 0 [mem 0x0000000040000000-0x000000004fffffff]
percpu: Embedded 9 pages/cpu s13136 r0 d23728 u36864
Built 1 zonelists, mobility grouping on. Total pages: 65024
Kernel command line: earlyprintk mem=256M console=ttySAC2,115200n8 PMOS_NO_OUTPUT_REDIRECT s3cfb.bootloaderfb=0x60000000 androidboot5
Unknown kernel command line parameters "PMOS_NO_OUTPUT_REDIRECT", will be passed to user space.
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes, linear)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 249628K/262144K available (3072K kernel code, 519K rwdata, 896K rodata, 1024K init, 207K bss, 12516K reserved, 0K cma-reserve)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1
rcu: Preemptible hierarchical RCU implementation.
rcu: RCU event tracing is enabled.
Trampoline variant of Tasks RCU enabled.
rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies.
NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
random: get_random_bytes called from start_kernel+0x374/0x5e4 with crng_init=0
Exynos5250: clock setup completed, armclk=1000000000
Switching to timer-based delay loop, resolution 41ns
clocksource: mct-frc: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 79635851949 ns
sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 89478484971ns
genirq: irq_chip COMBINER did not update eff. affinity mask of irq 57
arch_timer: cp15 timer(s) running at 24.00MHz (virt).
clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x588fe9dc0, max_idle_ns: 440795202592 ns
sched_clock: 56 bits at 24MHz, resolution 41ns, wraps every 4398046511097ns
Ignoring duplicate/late registration of read_current_timer delay
Console: colour dummy device 80x30
Calibrating delay loop (skipped), value calculated using timer frequency.. 48.00 BogoMIPS (lpj=240000)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
CPU: Testing write buffer coherency: ok
CPU0: Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable
/cpus/cpu@0 missing clock-frequency property
/cpus/cpu@1 missing clock-frequency property
CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
cblist_init_generic: Setting adjustable number of callback queues.
cblist_init_generic: Setting shift to 1 and lim to 1.
Setting up static identity map for 0x40100000 - 0x40100060
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...

CPU1: failed to boot: -110
smp: Brought up 1 node, 1 CPU
SMP: Total of 1 processors activated (48.00 BogoMIPS).
CPU: All CPU(s) started in SVC mode.
devtmpfs: initialized
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911