SAME54 Unlock: Authorized Firmware Recovery for Microchip’s Cortex-M4F MCU
The SAME54 unlock process extracts read-protected firmware from Microchip’s ATSAME54 series — a 120 MHz Cortex-M4F microcontroller with TrustZone-M, AES-256 hardware crypto, and a Secure Boot loader. Our engineers recover flash contents for clients who own the IP but have lost source code, need to maintain legacy products, or must verify production firmware against a golden image. Authorization and proof of ownership are required before work begins.
What Makes the SAME54 Difficult to Unlock?
Microchip built the SAM E54 around Arm’s TrustZone for Armv8-M architecture. This is not a simple read-out-protection fuse like older 8-bit parts. The device partitions memory into Secure and Non-Secure regions at the hardware level, and the on-chip boot ROM enforces these boundaries before any user code executes.
Key Security Features on the ATSAME54
| Feature | Detail | Impact on Unlock |
|---|---|---|
| TrustZone-M | Hardware-enforced Secure / Non-Secure partition | Firmware can reside entirely in the Secure region, invisible to standard debug |
| Secure Boot (Boot ROM) | SHA-256 hash verification of application before execution | Tamper attempts that alter flash will fail boot validation |
| BOCOR (Boot Configuration Row) | One-time or locked fuse row controlling debug access, NVM regions, and secure boot keys | If BOCOR locks DAL (Debug Access Level) to Level 0, SWD is fully disabled |
| AES-256 Crypto Engine | Hardware accelerator for AES, SHA, GCM, TRNG | Some designs encrypt flash payloads; raw dump is useless without the key |
| Debug Access Levels (DAL 0 / 1 / 2) | Three-tier debug gating — DAL 2 is open, DAL 0 is fully locked | DAL 0 disables all debug and chip-erase-only recovery path |
| NVM User Row Lock Bits | Per-region write/read lock for NVM | Even at DAL 1, certain regions can be individually locked out |
The combination of TrustZone partitioning and BOCOR-locked DAL 0 makes the SAME54 one of the more challenging Cortex-M4 targets in Microchip’s lineup. Unlike the older SAM D or SAM C families, a simple voltage-glitch on the reset line will not bypass the boot ROM’s hash check — the Secure Boot path verifies integrity before branching.
Is SAME54 Unlock Feasible for Every Device?
No. Feasibility depends on the specific security configuration burned into the target chip. We see three common scenarios in practice:
- DAL 2 (debug open, NVM lock bits set): Highest success rate. Flash regions are individually locked but the debug port remains active. Our tooling can typically recover full contents in 3–5 working days.
- DAL 1 (limited debug, Secure region hidden): Moderate difficulty. The Non-Secure application is accessible, but the Secure partition requires additional techniques. Success rate is high but turnaround extends to 8–12 working days.
- DAL 0 + Secure Boot (fully locked): Most restrictive. Debug is disabled entirely, and the boot ROM enforces a signed-image chain. Recovery may require semi-invasive approaches — decapsulation and micro-probing of the NVM bus — adding cost and time. Success is not guaranteed; we quote on a case-by-case basis after die inspection.
We provide a free feasibility assessment before quoting. Ship us one sample device (or provide the exact part number and BOCOR configuration if known) and our lab returns a go / no-go determination within 2–3 business days.
How Our Engineers Approach SAME54 Firmware Recovery
Step 1 — Configuration Analysis
We read the NVM User Row and BOCOR (to the extent the current DAL allows) to map the security posture: which regions are Secure, whether Secure Boot is active, and whether the crypto engine is used for flash encryption. This tells us the viable attack surface.
Step 2 — Non-Invasive Extraction Attempt
If the debug port retains any access, we use proprietary adapter firmware that communicates through the Cortex-M4 DAP at clock rates below the glitch-detection threshold. For DAL 2 targets, this alone recovers the full 1 MB flash image (ATSAME54P20A) or 512 KB (ATSAME54N19A) in a single session.
Step 3 — Semi-Invasive Techniques (DAL 0 Only)
When debug is fully disabled, we decapsulate the package under controlled acid etching, expose the die, and use UV or laser fault injection targeting the boot ROM’s DAL enforcement logic. This is precision work — the SAME54 die is fabricated on a 40 nm process, and the NVM array sits beneath several metal layers. Our success window depends on the specific silicon revision (A, B, or C stepping).
Step 4 — Verification & Delivery
Recovered firmware is verified by loading it onto a blank SAME54 of the same part number and confirming functional operation. We deliver a binary image (.bin / .hex), a memory map showing Secure and Non-Secure regions, and — where applicable — extracted AES keys if they were stored in the NVM User Row.
SAME54 Unlock Cost and Turnaround
| Security Level | Typical Price Range (USD) | Turnaround (Working Days) | Success Likelihood |
|---|---|---|---|
| DAL 2 + NVM lock bits | $500 – $900 | 3 – 5 | Very high |
| DAL 1 + TrustZone partition | $900 – $1,800 | 8 – 12 | High |
| DAL 0 + Secure Boot | $2,000 – $4,500+ | 12 – 20 | Case-dependent |
Pricing includes one sample device consumed during recovery (for semi-invasive work), the verified firmware binary, and a brief technical report. Volume discounts apply when recovering firmware from multiple SAME54 variants in one project. Rush service (≤5 days for DAL 1) carries a 30–40 % surcharge.
SAME54 vs. Similar Cortex-M4 Unlock Targets
Engineers often ask how the SAM E54 compares to other locked Cortex-M4F parts. The table below gives a rough comparison based on our lab experience:
| MCU Family | Core | Primary Protection | Relative Difficulty |
|---|---|---|---|
| Microchip SAME54 | Cortex-M4F @ 120 MHz | TrustZone-M + BOCOR DAL + Secure Boot | High |
| STM32MP1 series | Cortex-A7 + M4 | OTP fuses + Secure Boot + OP-TEE | Very High |
| NXP LPC4300 | Cortex-M4 + M0 | CRP levels 1–3 + AES OTF decryption | Medium–High |
| NXP i.MXRT | Cortex-M7 @ 600 MHz | HAB Secure Boot + encrypted XIP | Very High |
| Artery AT32F413 | Cortex-M4F @ 200 MHz | sLib + RDP | Medium |
The SAME54 sits in the upper tier of difficulty primarily because of TrustZone-M — a feature absent from most competing Cortex-M4 devices. Parts like the HDSC HC32F460 use simpler read-protection schemes and are generally faster and cheaper to recover.
Who Needs SAME54 Firmware Recovery?
- OEMs with lost source code: The original developer left, the repository is gone, and production must continue. We recover the binary so you can re-flash new units or port to a replacement MCU.
- Maintenance & repair shops: Field-deployed equipment running SAME54-based controllers needs firmware restoration after flash corruption or ESD damage.
- IP verification: You contracted a design house and want to confirm the delivered firmware matches the agreed specification — without relying on their build chain.
- End-of-life component migration: Microchip has not discontinued the SAME54 yet, but supply-chain volatility means some engineers are already planning cross-platform ports that require a reference binary.
Authorization and Legal Requirements
We perform SAME54 unlock exclusively for authorized parties. Before starting any work, we require a signed declaration of ownership or a letter of authorization from the IP holder. All projects are covered by a mutual NDA. For details on our compliance process and how we protect your intellectual property, see our trust and authorization policy.
Check feasibility for your project
Send the chip marking or board details and tell us what you need to recover. Add clear photos if available.
Request a feasibility reviewCan a fully DAL 0-locked SAME54 always be unlocked?
Not always. DAL 0 with Secure Boot active is the hardest configuration. Success depends on silicon revision, whether flash encryption is enabled, and the physical condition of the die. We provide a free feasibility check before committing — if recovery is not viable, you pay nothing.
Will the SAME54 be destroyed during the unlock process?
For DAL 2 and most DAL 1 cases, the chip is not damaged — we extract firmware through the debug interface. For DAL 0 semi-invasive recovery, the sample device is consumed during decapsulation. We recommend shipping two samples: one for recovery and one as a functional reference for verification.
What file formats do you deliver after SAME54 firmware extraction?
We deliver a raw .bin image covering the full flash address range (0x00000000–0x000FFFFF for 1 MB parts), an Intel .hex file, and a region map indicating Secure/Non-Secure boundaries. If the NVM User Row and BOCOR contents are recoverable, those are included as a separate binary.
How does TrustZone-M on the SAME54 differ from standard RDP on STM32?
STM32 RDP (Read-out Protection) is a single-level or two-level lock on the entire flash. TrustZone-M on the SAME54 creates a hardware-enforced partition: the Secure world has its own flash, SRAM, and peripherals invisible to the Non-Secure world. Bypassing TrustZone requires defeating the boot ROM’s partition enforcement, not just a debug-access fuse — a fundamentally harder problem.
Do you support all SAME54 package variants?
Yes. We handle ATSAME54P20A (128-pin TQFP), ATSAME54N20A (100-pin TQFP), and ATSAME54P19A (512 KB) variants. BGA packages (if custom) require an additional decapsulation fixture fee of approximately $150.
Working on a board like this?
Send the chip marking or two photos. You get feasibility, lead time and price within 24 hours, and the check costs nothing.
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