Why does the intel openvino R5 precompiled binaries give "not executable" on my raspberry pi OS? - raspberry-pi3

Question

The precompiled OpenVINO R5 distribution supports "raspbian 9" and gives some precompiled libraries for interfacing with their "movidius" usb stick. I tried it, and for example their precompiled "myriad_compile" program runs on raspbian indeed. Now I am doing the same on a custom built OS made with OpenADK. It has the official raspberry pi kernel, and uses glibc 2.27 and I'm using gcc 7.3.0 too. If I run the exact same binary, then I get this message:
# ./myriad_compile
mksh: ./myriad_compile: not executable: 32-bit ELF file
As a test, I tried to run a random binary from raspbian on my OS, and it works ok. I also tried to run a random binary from my OS on raspbian and it also worked ok.
So now I'm a bit puzzled what else could be the cause of this.
I did a readelf of the intel binary:
pi#raspberrypi:~/armv7l $ readelf -A ./myriad_compile
Attribute Section: aeabi
File Attributes
Tag_CPU_name: "7-A"
Tag_CPU_arch: v7
Tag_CPU_arch_profile: Application
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-2
Tag_FP_arch: VFPv3-D16
Tag_ABI_PCS_wchar_t: 4
Tag_ABI_FP_rounding: Needed
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_align_preserved: 8-byte, except leaf SP
Tag_ABI_enum_size: int
Tag_ABI_VFP_args: VFP registers
Tag_CPU_unaligned_access: v6
And here is the random executable called "watchdogctl" compiled by my toolchain from my own OpenADK OS:
pi#raspberrypi:~/armv7l $ readelf -A ./watchdogctl
Attribute Section: aeabi
File Attributes
Tag_CPU_name: "Cortex-A53"
Tag_CPU_arch: v8
Tag_CPU_arch_profile: Application
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-2
Tag_FP_arch: FP for ARMv8
Tag_Advanced_SIMD_arch: NEON for ARMv8
Tag_ABI_PCS_wchar_t: 4
Tag_ABI_FP_rounding: Needed
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_align_preserved: 8-byte, except leaf SP
Tag_ABI_enum_size: int
Tag_ABI_VFP_args: VFP registers
Tag_CPU_unaligned_access: v6
Tag_MPextension_use: Allowed
Tag_Virtualization_use: TrustZone and Virtualization Extensions
And this executable, coming from raspbian 9 runs on my OS without problems, and it's compiled for an older cpu version even:
pi#raspberrypi:~/armv7l $ readelf -A /usr/bin/wpa_passphrase
Attribute Section: aeabi
File Attributes
Tag_CPU_name: "6"
Tag_CPU_arch: v6
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-1
Tag_FP_arch: VFPv2
Tag_ABI_PCS_wchar_t: 4
Tag_ABI_FP_rounding: Needed
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_align_preserved: 8-byte, except leaf SP
Tag_ABI_enum_size: int
Tag_ABI_VFP_args: VFP registers
Tag_CPU_unaligned_access: v6
So can I get some more info about what is missing in my OS that is present on raspbian 9? I see that they use glibc 2.24 but I have 2.27 so I should be OK I think, and also I have gcc 7 and they use gcc 6, but it's all with the new ABI so I also don't think there is a problem there.
Any suggestions are welcome!
Thank

Answer 1

Sooooo, after some more searching and hair-pulling, it seems I have to enable the "thumb" compile options in my glibc compilation. I found out by compiling a subset of my own os again with that option, and then uploaded such a binary to my old OS, then saw the exact same message appear... so I then booted my thumb OS and it works!