wolfBoot, our secure bootloader, now runs on the Texas Instruments C2000 C28x DSP. We brought it up on the LAUNCHXL-F28P55X (TMS320F28P550SJ, 150 MHz). It boots the board directly from flash on a bare power-up, with no debugger attached, and it verifies a signed application before that application ever runs. C2000 parts are the workhorses of real-time control (motor drives, power conversion, digital power supplies). Those systems can now start from a verified, signed firmware image backed by a genuine hardware root of trust.
Secure boot, the C2000 way
On the C28x, wolfBoot first checks the firmware’s SHA-256 integrity. It then verifies the image’s ECC P-256 signature. Only a trusted image is allowed to run. Once the image is verified, the application runs execute-in-place (XIP) directly from flash. There is no boot-time copy step. The signing tools and key formats are the same ones used on every other wolfBoot target, so the workflow does not change just because the silicon is unusual.
Here is a real boot, captured on the board’s serial console at power-up:
Checking integrity...done Verifying signature...done hello from the wolfBoot app on F28P55x hello from the wolfBoot app on F28P55x
The signature verification is the heavy lifting on this 16-bit part. It takes roughly 0.65 seconds. The complete boot, from power-on to the running application, finishes in under a second.
The 16-bit-byte challenge
The C28x is a word-addressed DSP. Its smallest addressable unit is 16 bits, and it has no 8-bit byte at all. Secure boot, however, is fundamentally about hashing and verifying a stream of octets. The port closes that gap with wolfSSL’s wide-byte (CHAR_BIT != 8) support, which was merged in wolfSSL PR #10724. It pairs that support with a split flash layout. The image header is stored in a portable, byte-exact octet form, while the application stays a native, directly-executable image. This is wolfBoot’s first word-addressed target, and it builds with the TI cl2000 toolchain.
Running on hardware today
The port comes up over the board’s onboard XDS110 probe, and it is running on real silicon. It is available now in wolfBoot PR #860. This brings measured, authenticated boot to the C2000 real-time control ecosystem, alongside wolfBoot’s broad lineup of supported architectures.
If you have questions about any of the above, please contact us at facts@wolfssl.com or call us at +1 425 245 8247.
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