| Filename | Use case | |--------------------------------|-----------------------------------------------| | tiboot3.bin | Generic, defaults to R5 SPL | | tiboot3-strict.bin | Secure boot enforcement (no fallback) | | tiboot3-<board>-evm.bin | Board-specific configuration | | tiboot3_combined.bin | Includes SYSFW inside (for small boot media) | tiboot3.bin is a small but critical piece of the boot chain for TI K3 processors. It acts as the trusted first-stage loader running on the Cortex-R5F, handling low-level hardware initialization and security before handing off to U-Boot SPL ( tispl.bin ) and ultimately Linux. Debugging boot issues on K3 platforms should always start by confirming that tiboot3.bin is correctly built, signed (if HS), and placed on the boot media with the correct header. Report prepared for engineering use. For exact register-level details, refer to the Technical Reference Manual (TRM) of your specific TI K3 SoC.
To inspect the header:
| Offset | Size (bytes) | Field | Description | |--------|--------------|-------------------|--------------------------------------------------| | 0x00 | 4 | magic | 0x4152544C ("ARL") for ARM boot | | 0x04 | 4 | version | Header version (0x1 or 0x2) | | 0x08 | 4 | entry_point | Execution address (e.g., 0x41C00000 ) | | 0x0C | 4 | load_addr | Where ROM should copy the image | | 0x10 | 4 | image_size | Size of binary after header | | 0x14 | 4 | crc32 | Checksum | | 0x18 | 4 | flags | Security & boot flags | | ... | ... | ... | | | 0x40 | start | actual R5F code | Executable payload | On HS devices, the header is followed by a signature certificate. 0x41C00000 - 0x41C3FFFF OCRAM (256KB) – tiboot3.bin loaded here 0x41C00000 Entry point 0x41C04000 Stack 0x41C20000 Scratch / Heap Note: Some larger K3 devices load tiboot3.bin into a dedicated R5F TCM. 7. Build & Customization To rebuild or inspect:
# For AM62x SK EVM make am62x_evm_r5_defconfig make CROSS_COMPILE=arm-none-eabi- # or arm-linux-gnueabihf- ./spl/tiboot3.bin