STM32H747I - DeviceKey is not enabled

[JanneKiiskila]

Description

Target: DISCO_H747I
Toolchain: GCC_ARM
Tools: Mbed CLI 1.10.1
Mbed OS hash: 31114ba

Try to run device key tests as per Mbed OS documents.

mbed test -n features-device_key-tests-device_key-functionality -m DISCO_H747I -t GCC_ARM

Docs in: https://os.mbed.com/docs/mbed-os/v5.14/apis/devicekey.html

Error log:

Building project functionality (DISCO_H747I, GCC_ARM)
Scan: GCC_ARM
Scan: functionality
Compile [100.0%]: main.cpp
[Error] main.cpp@31,2: #error [NOT_SUPPORTED] DeviceKey needs to be enabled for this test
Memory map breakdown for built projects (values in Bytes):
| name | target | toolchain | static_ram | total_flash |
|------|--------|-----------|------------|-------------|


Build successes:
  * DISCO_H747I::GCC_ARM::MBED-BUILD


Build skips:
  * DISCO_H747I::GCC_ARM::FEATURES-DEVICE_KEY-TESTS-DEVICE_KEY-FUNCTIONALITY
[1570093741.66][root]Generating grammar tables from /usr/lib/python2.7/lib2to3/Grammar.txt
[1570093741.71][root]Generating grammar tables from /usr/lib/python2.7/lib2to3/PatternGrammar.txt
mbedgt: greentea test automation tool ver. 1.6.5
mbedgt: test specification file './BUILD/tests/DISCO_H747I/GCC_ARM/test_spec.json' (specified with --test-spec option)
mbedgt: using './BUILD/tests/DISCO_H747I/GCC_ARM/test_spec.json' from current directory!
mbedgt: detecting connected mbed-enabled devices...
[1570093741.87][mbedls.lstools_linux]Could not get serial devices by id. This could be because your Linux distribution does not use udev, or does not create /dev/serial/by-id symlinks. Please submit an issue to github.com/armmbed/mbed-ls.
mbedgt: no compatible devices detected
mbedgt: completed in 0.07 sec
mbedgt: exited with code 1
[mbed] ERROR: "mbedgt" returned error.
       Code: 1
       Path: "/home/jankii01/mbed/mbed-cloud-client-example-internal/mbed-os"
       Command: "mbedgt --test-spec ./BUILD/tests/DISCO_H747I/GCC_ARM/test_spec.json -n features-device_key-tests-device_key-functionality"
       Tip: You could retry the last command with "-v" flag for verbose output

Issue request type

[ ] Question
[ ] Enhancement
[x] Bug

Attn: @jeromecoutant @ARMmbed/team-st-mcd

[LMESTM]

@JanneKiiskila
Is there an example of a target that has this feature enabled by default ? and what are the requirements for a target to enable this, I don't see a description of what a target needs to implement (HAL layer ?) to support this feature ... can you clarify ?

If there is no HW dependency, then this can rather be enabled from mbed_app.json I think ...

[JanneKiiskila]

Well, plenty of other ST boards have it enabled - like F411RE, F429ZI, UBLOX_EVK_ODIN_W2.
@SeppoTakalo @MarceloSalazar - please comment on what it needs.

[JanneKiiskila]

I would venture a guess that it needs

       "components_add": ["FLASHIAP"],

added to the targets.json.

PR available; #11619

Indeed, with that it does compile.

Building project functionality (DISCO_H747I, GCC_ARM)
Scan: GCC_ARM
Scan: functionality
Compile [100.0%]: main.cpp
Link: functionality
Elf2Bin: functionality
| Module                          |         .text |       .data |        .bss |
|---------------------------------|---------------|-------------|-------------|
| [fill]                          |     148(+148) |     11(+11) |     37(+37) |
| [lib]/c.a                       | 28816(+28816) | 2472(+2472) |     89(+89) |
| [lib]/gcc.a                     |     772(+772) |       0(+0) |       0(+0) |
| [lib]/misc                      |     180(+180) |       4(+4) |     28(+28) |
| components/802.15.4_RF          |       84(+84) |       0(+0) |       0(+0) |
| components/storage              |   1006(+1006) |       0(+0) |       0(+0) |
| components/wifi                 |       34(+34) |       0(+0) |       0(+0) |
| drivers/source                  |   2226(+2226) |       0(+0) |     80(+80) |
| features/device_key             |   4594(+4594) |       0(+0) |   438(+438) |
| features/frameworks             |   6256(+6256) |     69(+69) |   449(+449) |
| features/mbedtls                | 11700(+11700) |       4(+4) |     40(+40) |
| features/storage                |   9584(+9584) |       0(+0) |   470(+470) |
| hal/mbed_critical_section_api.o |       88(+88) |       0(+0) |       2(+2) |
| hal/mbed_flash_api.o            |       14(+14) |       0(+0) |       0(+0) |
| hal/mbed_gpio.o                 |       78(+78) |       0(+0) |       0(+0) |
| hal/mbed_lp_ticker_api.o        |       28(+28) |       4(+4) |     64(+64) |
| hal/mbed_pinmap_common.o        |     188(+188) |       0(+0) |       0(+0) |
| hal/mbed_ticker_api.o           |   1166(+1166) |       0(+0) |       0(+0) |
| hal/mbed_us_ticker_api.o        |       30(+30) |       4(+4) |     64(+64) |
| hal/mpu                         |     208(+208) |       0(+0) |       0(+0) |
| platform/source                 |   4548(+4548) |   260(+260) |   284(+284) |
| rtos/source                     |   7224(+7224) |   168(+168) | 6228(+6228) |
| targets/TARGET_STM              | 20940(+20940) |     12(+12) | 1575(+1575) |
| Subtotals                       | 99912(+99912) | 3008(+3008) | 9848(+9848) |
Total Static RAM memory (data + bss): 12856(+12856) bytes
Total Flash memory (text + data): 102920(+102920) bytes

Image: BUILD/tests/DISCO_H747I/GCC_ARM/features/device_key/TESTS/device_key/functionality/functionality.bin

Memory map breakdown for built projects (values in Bytes):
| name          | target      | toolchain | static_ram | total_flash |
|---------------|-------------|-----------|------------|-------------|
| functionality | DISCO_H747I | GCC_ARM   |      12856 |      102920 |


Build successes:
  * DISCO_H747I::GCC_ARM::FEATURES-DEVICE_KEY-TESTS-DEVICE_KEY-FUNCTIONALITY
  * DISCO_H747I::GCC_ARM::MBED-BUILD

But I can't test, as the board is now refusing to connect over USB to Windows (or a Mac, either). Is there any way to rescue boot it or something similar? I could then run the relevant tests.

Currently, this hardware device is not connected to the computer. (Code 45)

To fix this problem, reconnect this hardware device to the computer.

A request for the USB device descriptor failed.

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-1864

[SeppoTakalo]

This is more complicated than just enabling the feature.
The API documentation does not help https://os.mbed.com/docs/mbed-os/v5.14/apis/devicekey.html as it only tells how to use the key. Does not tell how to set it up.

If short, devicekey requires flash, as it is stored inside KVStore. But if the location of KVStore is not set, then there cannot be devicekey.

But the OS cannot set the location of KVStore, as it is application dependant. Application may choose to split the flash in half, and use other part for FW update purposes, or it might use external storage for that.
Therefore any default locations that we give, are wrong for some use cases.

[MarceloSalazar]

Thanks Seppo for the reasoning.
I agree there might be multiple ways to setup the memory layout depending on the application or certain optimizations.

But can we facilitate a way to provide the default config in targets.json (or somewhere else) that would work out of the box with most applications, such Pelion client.
The developer should be able to override it as they see fit.

[JanneKiiskila]

Yep, we can have a sensible default - that passes for example the Mbed GreenTea tests. Defaulting to store KVStore at the end of the internal flash would be a quite safe assumption. Override is of course needed, as for this board for example, I would assume the following memory layout (for Pelion Device Management)

bank 1 - erase sector    0 - 1 * 128 kB - Bootloader
bank 1 - erase sector 1..7 - 7 * 128 kB - application
bank 2 - erase sector 0..1 - 2 * 128 kB - KVStore
bank 2 - erase sector 2..7 - 6 * 128 kB - FW Download area

On the other hand, option 2.

bank 1 - erase sector    0 - 1 * 128 kB - Bootloader
bank 1 - erase sector 1..7 - 7 * 128 kB - application
bank 2 - erase sector 0..5 - 6 * 128 kB - FW Download area
bank 2 - erase sector 6..7 - 2 * 128 kB - KVStore

Would work as well for the app, but of course one has to be "more" careful then with Firmware download size, that one does not ever overwrite KVStore, as that would brick the device. Doing it the other way around (option 1 above) - if the FW would be too large - we would likely just crash and reboot.

We probably also need to set the default size somewhere, because KVStore needs to be 2 flash erase sectors. The erase sector size is non-standard and especially ST board seem to have very many different sizes. In this particular board, the erase sectors are extremely large - 128 kilobytes each. Just out of curiosity - is there a special reason why they are so large?

[jeromecoutant]

Note that H747 is a dual core chip, see #11605
Basically:

• M7 core is using bank 1
• M4 core is using bank 2

@ABOSTM

[JanneKiiskila]

Oh. That's going to be a challenge then, possibly. The memory in H747 is normal memory in the sense that if you do sector erase OR you write to a flash bank, it prevents simultaneous code execution? Is there no way to configure the M4 to use SOME sectors from bank2 and leave rest of them to the M7? I.e. flash erase sector based access right management.

This should be documented somewhere.

Actually, I've now tried reading the STM documents on this topic, and on a quick glance at least - I can't find this limitation being mentioned there? Where is it documented?

• Reference manual, especially 4.3.4 Flash memory architecture and usage at page 158.
• Cortex M4
• Cortex M7

[JanneKiiskila]

Related PR by the way; https://github.com/ARMmbed/mbed-os/pull/11629/files - needs review/feedback from all chip vendors.

[JanneKiiskila]

Using this change:

jankii01@ubuntu:~/mbed/mbed-os-devicekey/mbed-os$ git diff
diff --git i/features/storage/kvstore/conf/tdb_internal/mbed_lib.json w/features/storage/kvstore/conf/tdb_internal/mbed_lib.json
index 0c83bf8294..66126152ab 100644
--- i/features/storage/kvstore/conf/tdb_internal/mbed_lib.json
+++ w/features/storage/kvstore/conf/tdb_internal/mbed_lib.json
@@ -17,7 +17,7 @@
         },
         "DISCO_H747": {
             "internal_size": "256*1024*1024",
-            "internal_base_address": "0x081C0000"
+            "internal_base_address": "0x080C0000"

I.e. based on this info, put the KVStore to 2 last erase sectors of bank 1.

Progress, got this far now:

mbedgt: test on hardware with target id: 081402210248650C3D0CFC25
mbedgt: test suite 'mbed-os-features-storage-tests-kvstore-tdbstore_whitebox' ........................ OK in 10.67 sec
	test case: 'TDBStore: Error inject test' ..................................................... OK in 0.11 sec
	test case: 'TDBStore: Multiple set test' ..................................................... OK in 0.11 sec
	test case: 'TDBStore: White box test' ........................................................ OK in 0.10 sec
mbedgt: test case summary: 3 passes, 0 failures
mbedgt: all tests finished!
mbedgt: shuffle seed: 0.2698047915
mbedgt: test suite report:
| target            | platform_name | test suite                                                          | result | elapsed_time (sec) | copy_method |
|-------------------|---------------|---------------------------------------------------------------------|--------|--------------------|-------------|
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-direct_access_devicekey_test | FAIL   | 19.71              | default     |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | OK     | 29.59              | default     |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-tdbstore_whitebox            | OK     | 10.67              | default     |
mbedgt: test suite results: 1 FAIL / 2 OK
mbedgt: test case report:
| target            | platform_name | test suite                                                          | test case                                                           | passed | failed | result | elapsed_time (sec) |
|-------------------|---------------|---------------------------------------------------------------------|---------------------------------------------------------------------|--------|--------|--------|--------------------|
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-direct_access_devicekey_test | Testing direct access to devicekey with tdb over flashiap remainder | 1      | 0      | OK     | 2.94               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-direct_access_devicekey_test | Testing direct access to devicekey with tdb over last two sectors   | 0      | 1      | FAIL   | 2.98               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-direct_access_devicekey_test | Testing direct access to injected devicekey                         | 1      | 0      | OK     | 2.85               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_buffer_null_size_not_zero                                       | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_buffer_size_bigger_than_data_real_size                          | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_buffer_size_is_zero                                             | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_buffer_size_smaller_than_data_real_size                         | 1      | 0      | OK     | 0.08               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_existed_key                                                | 1      | 0      | OK     | 1.88               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_info_null                                                  | 1      | 0      | OK     | 0.04               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_key_length_exceeds_max                                     | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_key_null                                                   | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_non_existing_key                                           | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_overwritten_key                                            | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_info_removed_key                                                | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_key_length_exceeds_max                                          | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_key_null                                                        | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_key_that_was_set_twice                                          | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_non_existing_key                                                | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_removed_key                                                     | 1      | 0      | OK     | 0.04               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | get_several_keys_multithreaded                                      | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_close_right_after_iterator_open                            | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_empty_list                                            | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_empty_list_keys_removed                               | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_empty_list_non_matching_prefix                        | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_full_list                                             | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_key_size_zero                                         | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_one_key_list                                          | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_path_check                                            | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_remove_while_iterating                                | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_next_several_overwritten_keys                              | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | iterator_open_it_null                                               | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | kvstore_init                                                        | 1      | 0      | OK     | 2.82               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | remove_existed_key                                                  | 1      | 0      | OK     | 0.04               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | remove_key_length_exceeds_max                                       | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | remove_key_null                                                     | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | remove_non_existing_key                                             | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | remove_removed_key                                                  | 1      | 0      | OK     | 0.04               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_buffer_null_size_not_zero                                       | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_buffer_size_is_zero                                             | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_length_exceeds_max                                          | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_null                                                        | 1      | 0      | OK     | 0.04               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_value_fifteen_byte_size                                     | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_value_five_byte_size                                        | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_value_one_byte_size                                         | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_value_seventeen_byte_size                                   | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_key_value_two_byte_size                                         | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_same_key_several_time                                           | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_several_key_value_sizes                                         | 1      | 0      | OK     | 0.06               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_several_keys_multithreaded                                      | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_several_unvalid_key_names                                       | 1      | 0      | OK     | 0.05               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_write_once_flag_try_remove                                      | 1      | 0      | OK     | 1.91               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-static_tests                 | set_write_once_flag_try_set_twice                                   | 1      | 0      | OK     | 0.07               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-tdbstore_whitebox            | TDBStore: Error inject test                                         | 1      | 0      | OK     | 0.11               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-tdbstore_whitebox            | TDBStore: Multiple set test                                         | 1      | 0      | OK     | 0.11               |
| DISCO_H747I-ARMC6 | DISCO_H747I   | mbed-os-features-storage-tests-kvstore-tdbstore_whitebox            | TDBStore: White box test                                            | 1      | 0      | OK     | 0.1                |
mbedgt: test case results: 1 FAIL / 54 OK
mbedgt: completed in 60.35 sec

So, only one test failing. I wonder if the | mbed-os-features-storage-tests-kvstore-direct_access_devicekey_test with tdb over last two sectors actually makes some hard assumptions here (like thename would imply) that fail with this special HW? Is the bank2 out of range, even you run it in single-core mode? Which would then explain why this would fail on this HW.

[JanneKiiskila]

Yep, that is the case. Adding some prints there it's easy to see, that.

mbed-os/features/storage/TESTS/kvstore/direct_access_devicekey_test/main.cpp

Lines 180 to 184 in 2e09a27

	int err = get_virtual_TDBStore_position(0, 0, false, &flash_bd_start_address, &flash_bd_end_address);
	TEST_SKIP_UNLESS_MESSAGE(err != -2, "Test skipped. Not enough available space on Internal FlashIAP");
	TEST_ASSERT_EQUAL(0, err);
	uint32_t flash_bd_size = flash_bd_end_address - flash_bd_start_address;

If you add printouts there, it will give you this;

[1570191918.98][CONN][RXD] Test Direct Access To DeviceKey Test Last Two Sectors
[1570191919.01][CONN][RXD] flash_bd_start_address = 0x81c0000
[1570191919.05][CONN][RXD] flash_bd_end_address = 0x8200000
[1570191919.08][CONN][RXD] flash_bd_size = 0x40000

Which places this test to be executed with KVStore being in the last two erase sectors of bank 2, which the CPU in this case can't access? Now the bigger philosophical/architectural question is - how on earth should this be handled? Should the flash.h file be changed, so that for this target - the boards should only list 1 bank with size of 1 megabyte, instead of the true HW? Then the other M4 target will see only the bank 2 with size of 1 megabyte?

Having a target specific "oh, with this board I'll drop it to end of bank1 in test case" will just be and endless nightmare going forwards...

@bulislaw @kjbracey-arm @ARMmbed/team-st-mcd - time to chime in.