Patch Failed (Samsung SM-A530F) (4.4.302-p6-Eureka_R25U)

[kgursu]

I worked with an AI and it gave me this output here. kallsyms.txt is the first part of the output, the second part is also here.
zcat /proc/config.gz | grep KALLSYMS
CONFIG_KALLSYMS=y
# CONFIG_KALLSYMS_ALL is not set

kallsyms.txt

Here is the kernel file:

kernel.txt

kptools fails with "kernel image magic error" when ARM64 header magic sits at 0x30

Summary

kptools rejects a valid arm64 kernel because it looks for the ARMd magic
(0x644D5241) only at offset 0x38. On this kernel the magic is at 0x30, so
patching aborts before any analysis starts.

Device / build

Device	jackpotlte (Samsung Galaxy A8 2018, SM-A530F)
SoC	Exynos 7885
ROM	XROM V161 (Android 16 base)
Kernel	4.4.302-p6-Eureka_R25U
Toolchain	Neutron clang 18.0.0git
Build date	Wed Jun 17 06:27:23 KST 2026
Boot header	version 0, pagesize 2048, Samsung SEANDROID footer present

Kernel header dump

First 64 bytes of the unpacked kernel (from magiskboot unpack):

00000000  10 00 00 14 00 00 00 00  00 00 08 00 00 00 00 00
00000010  00 20 D1 01 00 00 00 00  0A 00 00 00 00 00 00 00
00000020  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
00000030  41 52 4D 64 00 00 00 00  1F 20 03 D5 1F 20 03 D5

Decoded:

• 0x00 code0 = 0x14000010 = b #0x40, so execution starts at 0x40
• 0x08 text_offset = 0x80000
• 0x10 image_size = 0x01D12000
• 0x18 flags = 0x0A (little endian, 4K pages)
• 0x30 ARMd magic
• 0x38 and 0x3C = d503201f (NOP), never executed

The header carries one fewer reserved 64-bit field than the layout in
Documentation/arm64/booting.rst, which shifts magic from 0x38 to 0x30.
This comes from a modified arch/arm64/kernel/head.S in the ROM's kernel source.

Workaround confirmed

Writing a second copy of the magic into the unused NOP slot at 0x38 lets
kptools proceed past header validation. File size is unchanged and the kernel
still boots to the same point, since code0 branches over that region.

printf '\101\122\115\144\000\000\000\000' | \
  dd of=kernel bs=1 seek=56 conv=notrunc

After this, kptools reads the header, resolves linux_banner, kernel version,
and both kallsyms token tables. (It then fails for a separate reason, filed
upstream — see the other report.)

Suggested fix

Instead of reading the magic at a fixed 0x38, scan the first 64 or 128 bytes in
4-byte steps for 0x644D5241 and derive the header layout from where it is
found. This keeps standard kernels working and accepts variants like this one.