[MTCD Software Development] switchboy:
I dont have acces to my headunit at the moment. The wife has taken the car for a drive. So I did the next best thing and used readelf on a ubuntu vm to try and find dependencies of the sdsdk binairy. Here is the raw output:

@Butterfly:~/Desktop$ readelf -And sdsdk

Dynamic section at offset 0xbe65c contains 33 entries:
Tag Type Name/Value
0x00000003 (PLTGOT) 0xbfd84
0x00000002 (PLTRELSZ) 1248 (bytes)
0x00000017 (JMPREL) 0x9bc0
0x00000014 (PLTREL) REL
0x00000011 (REL) 0x2cb0
0x00000012 (RELSZ) 28432 (bytes)
0x00000013 (RELENT) 8 (bytes)
0x6ffffffa (RELCOUNT) 3551
0x00000015 (DEBUG) 0x0
0x00000006 (SYMTAB) 0x148
0x0000000b (SYMENT) 16 (bytes)
0x00000005 (STRTAB) 0x1258
0x0000000a (STRSZ) 4590 (bytes)
0x00000004 (HASH) 0x2448
0x00000001 (NEEDED) Shared library: [libtinyalsa.so]
0x00000001 (NEEDED) Shared library: [libmedia.so]
0x00000001 (NEEDED) Shared library: [libutils.so]
0x00000001 (NEEDED) Shared library: [libbinder.so]
0x00000001 (NEEDED) Shared library: [liblog.so]
0x00000001 (NEEDED) Shared library: [libstdc++.so]
0x00000001 (NEEDED) Shared library: [libm.so]
0x00000001 (NEEDED) Shared library: [libc.so]
0x00000001 (NEEDED) Shared library: [libdl.so]
0x0000001a (FINI_ARRAY) 0xbc3b8
0x0000001c (FINI_ARRAYSZ) 8 (bytes)
0x00000019 (INIT_ARRAY) 0xbc3c0
0x0000001b (INIT_ARRAYSZ) 36 (bytes)
0x00000020 (PREINIT_ARRAY) 0xbc3e4
0x00000021 (PREINIT_ARRAYSZ) 0x8
0x00000016 (TEXTREL) 0x0
0x0000001e (FLAGS) TEXTREL BIND_NOW
0x6ffffffb (FLAGS_1) Flags: NOW
0x00000000 (NULL) 0x0

Displaying notes found in: .note.gnu.gold-version
Owner Data size	Description
GNU 0x00000009	NT_GNU_GOLD_VERSION (gold version)
Version: gold 1.11
Attribute Section: aeabi
File Attributes
Tag_CPU_name: "ARM v7"
Tag_CPU_arch: v7
Tag_CPU_arch_profile: Application
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-2
Tag_FP_arch: VFPv3
Tag_Advanced_SIMD_arch: NEONv1
Tag_ABI_PCS_GOT_use: GOT-indirect
Tag_ABI_PCS_wchar_t: 4
Tag_ABI_FP_denormal: Needed
Tag_ABI_FP_exceptions: Needed
Tag_ABI_FP_number_model: IEEE 754
Tag_ABI_align_needed: 8-byte
Tag_ABI_enum_size: int
Tag_ABI_HardFP_use: Deprecated
Tag_ABI_optimization_goals: Aggressive Speed
Tag_CPU_unaligned_access: v6
Tag_ABI_FP_16bit_format: IEEE 754
Tag_DIV_use: Not allowed
Tag_Virtualization_use: TrustZone

It would seem that the only libs this file depends on are the following:

0x00000001 (NEEDED) Shared library: [libtinyalsa.so]
0x00000001 (NEEDED) Shared library: [libmedia.so]
0x00000001 (NEEDED) Shared library: [libutils.so]
0x00000001 (NEEDED) Shared library: [libbinder.so]
0x00000001 (NEEDED) Shared library: [liblog.so]
0x00000001 (NEEDED) Shared library: [libstdc++.so]
0x00000001 (NEEDED) Shared library: [libm.so]
0x00000001 (NEEDED) Shared library: [libc.so]
0x00000001 (NEEDED) Shared library: [libdl.so]

So now we need the right version of these in /system/lib/ and it might work.

EDIT:

I also ran this command on gocsdk:

0x00000001 (NEEDED) Shared library: [libbinder.so]
0x00000001 (NEEDED) Shared library: [libmedia.so]
0x00000001 (NEEDED) Shared library: [libutils.so]
0x00000001 (NEEDED) Shared library: [liblog.so]
0x00000001 (NEEDED) Shared library: [libstdc++.so]
0x00000001 (NEEDED) Shared library: [libm.so]
0x00000001 (NEEDED) Shared library: [libc.so]
0x00000001 (NEEDED) Shared library: [libdl.so]

So it seems that libtinyalsa.so might be our missing file! :D

sdsdk needs it and gocsdk doesn't.

Edit 2:

Okay I've extracted the missing files from a recent android 6 ROM which had working BT on my unit. I've created an archive with all the files that I think are missing in android 8 in their respective folders. Copy and paste to the right folders on your unit and set permissions to 777 for each file (you'll need a root browser for this). I've hadn't had time to test it for myself but this will hopefully fix this mess.

Edit 3:

Well it seems that the missing files I gathered up aren't complete yet. I can comfirm that 'sdsdk' is indeed crashing because it is missing dependencies. Executing the file from terminal is generating this error message.

"CANNOT LINK EXECUTABLE 'sdsdk' has text relocations"

Sadly I am currently at a loss getting the name and paths out of 'sdsdk' with readelf.

Edit 4:

After more reading it would seem that google disabled text relocations for applications running in userland. So this error seems logical since I was running the terminal in userland .