MIMXRT1050_EVK: Add TRNG support

[mmahadevan108]

Description

Add TRNG support

Pull request type

[ ] Fix
[ ] Refactor
[X] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

[mmahadevan108]

Below are the test results:
mbedgt: test on hardware with target id: 0227000041114e450004300ac2040020df91000097969900
mbedgt: test suite 'mbed-os-tests-mbed_hal-trng' ..................................................... OK in 12.50 sec
test case: 'mbed-os-tests-mbed_hal-trng' ..................................................... OK in 12.50 sec
mbedgt: test case summary: 1 pass, 0 failures
mbedgt: all tests finished!
mbedgt: shuffle seed: 0.6729389334
mbedgt: test suite report:

target	platform_name	test suite	result	elapsed_time (sec)	copy_method
MIMXRT1050_EVK-GCC_ARM	MIMXRT1050_EVK	mbed-os-tests-mbed_hal-trng	OK	12.5	default
mbedgt: test suite results: 1 OK
mbedgt: test case report:
target	platform_name	test suite	test case	passed	failed
esult	elapsed_time (sec)
------------------------	----------------	-----------------------------	-----------------------------	--------	--------
------	--------------------
MIMXRT1050_EVK-GCC_ARM	MIMXRT1050_EVK	mbed-os-tests-mbed_hal-trng	mbed-os-tests-mbed_hal-trng	1	0
K	12.5
mbedgt: test case results: 1 OK

[mmahadevan108]

cc @maclobdell

[ciarmcom]

@mmahadevan108, thank you for your changes.
@maclobdell @ARMmbed/mbed-os-maintainers please review.

[0xc0170]

@ARMmbed/mbed-os-crypto please review TRNG implementation

[yanesca]

Hi, I am trying to review based on this:
http://www.mouser.com/ds/2/813/K66P144M180SF5RMV2-1074869.pdf

I am trying to understand how the value of a single output register the manual talks about gets into the 16 registers the code in targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_MIMXRT1050/drivers/fsl_trng.c reads it from. Am I looking at the wrong manual?

[mmahadevan108]

Please refer to the MXRT1050 manual at the below link:
https://www.nxp.com/docs/en/reference-manual/IMXRT1050RM.pdf

[yanesca]

Could we please correct this reference to "i.MX RT1050 Processor ReferenceManual" Section 6.6?

[mmahadevan108]

Thank you for spotting this, I have updated the file to correct this.

[yanesca]

@mmahadevan108 Thank you very much for the link! There is a short section about the TRNG and some information about the corresponding registers. What I was looking for is an estimate about the entropy content of the 512 output bits. Is that information available somewhere?

[mmahadevan108]

Apologies for the lack of information in the reference manual. I do see a security manual at the below link, however this manual is not publicly available and will have to be requested through the NXP FAE person that ARM works with.

https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/i.mx-rt-series/i.mx-rt1050-crossover-processor-with-arm-cortex-m7-core:i.MX-RT1050?tab=Documentation_Tab

Unfortunately I have no information on the entropy contents.

[0xc0170]

@yanesca How can we progress this?

[yanesca]

I've got the documentation, I am going read it and review the PR as soon as I can find the time.

[0xc0170]

Ci started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 1
Build artifacts