Add support for PQC secure boot with MCXA 5xx family of MCUs by alamfarjadf · Pull Request #36 · OpenDevicePartnership/ec-slimloader

alamfarjadf · 2026-04-02T20:29:28Z

Adding ROM API support for MCXA 5xx family with Post-Quantum Cryptography hybrid secure boot (ML-DSA-87 and EC-DSA P384).

Added ec-slimloader-mcxa under libs and mcxa-577 examples (bootloader and blinky).

Validated on MCXA577 eval kit with hybrid signed AHAB MBI images which successfully authenticate and boot up.

Not yet added to PR: Imaging tools for MCXA (being worked on as an independent library).

To-dos:

Move journal to external flash with flexSPI IP (already done to minimize RT6 impacts).
Use memory.toml for memory mapping.
Split MCXA ROM APIs as independent library under /libs
Update readme.
General ROM API safety and type improvements.
Add journal update to App.

diondokter

Is there any split image support yet? If there is I can't find it (so please point me to it 😊)
Or are we assuming the ROM memory mapped it for us already?

JamesHuard · 2026-06-11T15:32:12Z

Is there any split image support yet? If there is I can't find it (so please point me to it 😊) Or are we assuming the ROM memory mapped it for us already?

The image header that the NXP ROM APIs/ROM Loader use has a section for identifying multiple images. The thought here is that it'd be a 'no-op' from an implementation perspective of the SBL firmware to support split-image, because it's already baked into the infra. The change then is in the build tooling to actually generate these additional fields and hashes.

That's also where the open question is to NXP around if the secondary image(s) are simply hash verified or included in the full image signature block.

alamfarjadf · 2026-06-11T20:58:27Z

Is there any split image support yet? If there is I can't find it (so please point me to it 😊) Or are we assuming the ROM memory mapped it for us already?

@diondokter There is no split image support yet.

From my understanding, the split image on the verification side should be opaque to the caller, IF the image is built correctly (The idea here is that the second executable occupies the area for the CRC binary and is hashed and verified automatically by the APIs). But that idea hasn't been validated yet partly because I haven't been able to generate a split image binary yet.

We have reached out to NXP for further clarification and are awaiting their response.

When we have a split binary, the API will use the single AHAB container to hash both binaries and validate them, so infrastructure needed is mostly on the artifact generation side (which is not published as part of this public PR yet but available in private repos).

diondokter

Thanks for the responses so far!

What's the reason for trying to massage ec-slimloader into supporting both chips and a radically different way in how the code is executed?

The non-imxrt6xx parts are pretty small. All ec-slimloader does is a little bit of in-flash state management, verifying the image and then jump to it.

But for mcxa, the verification is different. And because we're gonna be running in flash, we need to be able to swap partitions, which means that the state management needs to change too. All that's left is doing the boot jump which is like 20 lines of code.

So why take on the complexity of making everything share the same codebase and structure?

diondokter · 2026-06-15T12:41:11Z

Ok, I've been trying to build this PR and that just doesn't work.

Wrong embassy-time imports (though I could fix that)
target folders not in gitignore
builds on an embassy-mcxa branch that isn't able to be built in CI: [MCXA] make SGI drivers compatible with embassy-rs peripheral style embassy-rs/embassy#5612

JamesHuard · 2026-06-15T15:26:53Z

Thanks for the responses so far!

What's the reason for trying to massage ec-slimloader into supporting both chips and a radically different way in how the code is executed?

The non-imxrt6xx parts are pretty small. All ec-slimloader does is a little bit of in-flash state management, verifying the image and then jump to it.

But for mcxa, the verification is different. And because we're gonna be running in flash, we need to be able to swap partitions, which means that the state management needs to change too. All that's left is doing the boot jump which is like 20 lines of code.

So why take on the complexity of making everything share the same codebase and structure?

This is a fair question.

The main thing I think we want is a common interface to the boot sequencing, particularly the journal management and rollback behaviors we want to be 'the same'. We'd like to have a common 'entry point' for various products/OEM lines that give a standard set of behavioral guarantees, even if the underlying hardware mechanisms (secure signing checks, memory layouts, extra steps) are radically different. Almost all, or perhaps all, of this is achieved through the Journal and banking management.

If the current structures/interfaces are too restrictive and getting in the way, then let's evolve. If that means a new interpretation of 'ec-slimloader' as just a trait and then some chip-specific impl's of that trait, I think that's fine.

What do you see as the lowest friction approach here? From my "500-meter high" view, I'd think the basic bootloading process is 'the same', that is:

Setup hardware
Read journal state
Either load valid image, or engage rollback recovery

2&3 being 'the same' is the useful thing here. That could easily be a small helper function on top of a trait that consumes the journal and hardware instances, which I think isn't too far off from what we have today, but there might be too much coupling here if it adds friction. I'm totally open to restructuring to make our job here easier

alamfarjadf · 2026-06-15T17:32:19Z

Ok, I've been trying to build this PR and that just doesn't work.

Wrong embassy-time imports (though I could fix that)

target folders not in gitignore

builds on an embassy-mcxa branch that isn't able to be built in CI: [MCXA] make SGI drivers compatible with embassy-rs peripheral style embassy-rs/embassy#5612

For 1, The embassy dependencies have not been updated in a while.

Added gitignore.

For 3, The CI build for that branch fails because chip JSON files in NXP-PAC are missing the SGI clock and power gating attributes. I was going to update them but never got the time. Once the SGI PAC is re-generated with the attributes, it will build successfully (does so in local).

diondokter · 2026-06-22T12:38:18Z

Validated on MCXA577 eval kit with hybrid signed AHAB MBI images which successfully authenticate and boot up.

@alamfarjadf do you have a script lying around with which you did this? Or do you have it written down.
If not, I have to duplicate the time looking into this

alamfarjadf · 2026-06-22T21:02:36Z

Validated on MCXA577 eval kit with hybrid signed AHAB MBI images which successfully authenticate and boot up.

@alamfarjadf do you have a script lying around with which you did this? Or do you have it written down. If not, I have to duplicate the time looking into this

@diondokter Are you interested in the AHAB signed image generation process?

Yes, I have a CLI tool that does this. I just gave you access to the private repo with the tool (ahab-mbi-tool). Build it, run the .exe with the --build path and the blinky BIN file and you will be able to generate a signed MBI image.

Caveats:

You need ECDSA keys (public and the corresponding signer) and MLDSA-87 keys. The current MLDSA keys are from TSS' auto-signer CLI tool (which you would need to separately get access to). For signing the image, you can use the tool to sign ECDSA and MLDSA.

OR are you simply interested in the signed binaries to flash? On an "un-provisioned" eval. kit, you can flash both binaries (BL and blinky app) in the corresponding flash locations and it should validate and boot (dev mode).

To provision the MCU, refer to mcxa-provisioning part of this PR.

…nctions

diondokter · 2026-08-19T08:53:59Z

All the examples should follow the same names. So this example should be called examples/mcxa-577/application and the bootloader should be examples/mcxa-577/bootloader

diondokter · 2026-08-19T09:02:59Z

+embassy-sync = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-mcxa = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0", default-features = false }
+embassy-executor = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0", default-features = false }
+embassy-time = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+
+[patch.crates-io]
+embassy-embedded-hal = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-executor = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-executor-macros = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-futures = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-hal-internal = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-sync = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-time = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-time-driver = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }
+embassy-time-queue-utils = { git = "https://github.com/embassy-rs/embassy", rev = "f21d63db2d104a3b4c070408e529c109a64e65b0" }


These should used released versions of embassy (when available, so only mcxa should be a git dep)

diondokter · 2026-08-19T09:14:03Z

+cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
+cortex-m-rt = { version = "0.7", features = ["set-sp", "set-vtor"] }
+defmt = "1.0"
+defmt-rtt = "1.0"
+embassy-mcxa = { workspace = true, features = ["rt", "defmt", "mcxa5xx"] }
+embassy-executor = { workspace = true, features = ["platform-cortex-m", "executor-thread"] }
+embassy-time = { workspace = true, features = ["defmt", "defmt-timestamp-uptime"] }
+panic-probe = { version = "1.0", features = ["print-defmt"] }


This needs to be more consistent. Use the workspace or don't.

diondokter · 2026-08-19T12:46:55Z

+    }
+}
+
+pub type BootloaderTree = RomApi;


diondokter · 2026-08-19T12:48:16Z

+/// Helper function to get a pointer to the flash driver API from the ROM API tree.
+pub fn flash_driver() -> FlashDriver {
+    // Match NXP usage: g_bootloaderTree->flashDriver->...
+    // The bootloader tree stores a direct pointer to the flash driver interface.
+    bootloader_tree().flash_api()
+}


Useless helpers (below too). People can call rom_api().flash_api() themselves just fine and that's a lot clearer then what's actually being done

…er cargo.toml

jerrysxie · 2026-08-20T04:25:23Z

@alamfarjadf I realized that the CI broken, so I put up a PR to fix it: #46.

diondokter · 2026-08-20T09:57:29Z

Instead of piling on even more comments here, I've just done the things I want to see and made a PR against this branch here: alamfarjadf#1

It removes almost 2k lines of code

felipebalbi · 2026-08-20T20:18:20Z

BTW, this should probably get a run through miri, no?

jerrysxie · 2026-08-25T17:05:28Z

@alamfarjadf There is a merge conflict, please resolve so CI can run.

…evicePartnership#46) - Replace the silently passing clippy GH action with direct calls to clippy - Fix all the clippy warnings that came up - Lock down dependencies by checking Cargo.lock into source control and add `--locked` flag to all CI workflows where it is applicable

alamfarjadf · 2026-08-26T01:25:22Z

@alamfarjadf There is a merge conflict, please resolve so CI can run.

Merge conflict resolved in check.yml.

…77-bootloader # Conflicts: # .github/workflows/check.yml

jerrysxie · 2026-08-27T20:38:29Z

@alamfarjadf @gjpmsft @diondokter

This PR has gone through a few iterations and has lots of comments. It has become a bit unwieldy. I created a branch: https://github.com/OpenDevicePartnership/ec-slimloader/tree/mcxa-secure-boot. Let's target this PR to that branch. Create issues for all the unresolved comments, and we can work through the issue in that branch. Then we can merge the final product into main.

diondokter · 2026-08-27T20:39:34Z

Yes sounds good

alamfarjadf added 5 commits April 2, 2026 12:20

add MCXA577 bootloader, blinky app, and ec-slimloader-mcxa library

5ab9523

fix embassy dependency resolution and clippy warning

e6c73e3

remove load.rs from PR (kept locally, unused)

6377471

Merge branch 'main' into mcxa-577-bootloader

d5f2142

git dep changes and SGI signature updates; add rustdoc comments

502cd91

jerrysxie assigned jerrysxie and unassigned jerrysxie Apr 7, 2026

alamfarjadf commented Apr 9, 2026

View reviewed changes

Comment thread libs/ec-slimloader-mcxa/src/lib.rs

alamfarjadf added 2 commits April 15, 2026 09:26

Merge branch 'main' into mcxa-577-bootloader

e0f5580

mcxa cmpa/cfpa provisioning

f185706

alamfarjadf force-pushed the mcxa-577-bootloader branch from 08f268c to f185706 Compare April 27, 2026 20:14

alamfarjadf added 4 commits May 15, 2026 18:43

fix STRIDE / hyenas CWE issues

13e2e38

Harden CMPA scratch lifecycle staging

59d2344

Merge branch 'main' into mcxa-577-bootloader

bbfa20c

Merge branch 'main' into mcxa-577-bootloader

27d4f5f

diondokter reviewed Jun 11, 2026

View reviewed changes

diondokter reviewed Jun 15, 2026

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Comment thread libs/ec-slimloader-mcxa/src/rom_api.rs Outdated

Comment thread libs/ec-slimloader-mcxa/src/rom_api.rs Outdated

gitignore

fb0c240

alamfarjadf added 5 commits July 9, 2026 15:55

align embassy dependencies; use cortex-m reset; remove OTP ROM API fu…

4a573ec

…nctions

lifecycle provisioning updates

4537a8b

provisining flow updates

b517176

consolidate provisioning interface

3e9eeaa

jump update, use header validation; ROTKH provisioning updates

78ffbcf

alamfarjadf added 2 commits August 18, 2026 13:56

defmt and mcxa app config updates

f1f39e0

re-enable full authentication flow with EXT flash journal

46f4df4

diondokter reviewed Aug 19, 2026

View reviewed changes

alamfarjadf added 2 commits August 19, 2026 17:33

update app memory.x and build.rs; add mcxa-memory TOML; fix provision…

e744a64

…er cargo.toml

harden dev mode detection; defmt format fix

9fb2ae9

diondokter reviewed Aug 20, 2026

View reviewed changes

Comment thread libs/ec-slimloader-mcxa/src/verification.rs

diondokter reviewed Aug 20, 2026

View reviewed changes

Comment thread mcxa-security-provisioning/src/lifecycle_provisioning.rs

diondokter reviewed Aug 24, 2026

View reviewed changes

Comment thread libs/ec-slimloader-mcxa/src/verification.rs

fix LC provisioning bug on new CFPA write; remove asm from jump.rs

4876e49

jerrysxie and others added 2 commits August 25, 2026 17:42

Merge branch 'main' into mcxa-577-bootloader

65ede62

alamfarjadf added 6 commits August 26, 2026 11:12

bare-metal version patch for 1.93; cargo.lock;

0470342

Merge remote-tracking branch 'origin/mcxa-577-bootloader' into mcxa-5…

4d32a36

…77-bootloader # Conflicts: # .github/workflows/check.yml

Fix embassy-time-driver conflict; as_chunks; rustc_version license

f50e7fd

FI hardening; cargo fmt/ check updates

a94e3f7

cargo MSRV check updates

5214cd0

cargo nightly fmt

fd0be78

alamfarjadf changed the base branch from main to mcxa-secure-boot August 27, 2026 22:00

address comments on error types

d7f47a0

gjpmsft closed this Aug 28, 2026

gjpmsft reopened this Aug 28, 2026

gjpmsft approved these changes Aug 28, 2026

View reviewed changes

jerrysxie merged commit 7926ae3 into OpenDevicePartnership:mcxa-secure-boot Aug 28, 2026
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