3.1.1.4. Bootflow
3.1.1.4.1. Boot Flow
On K3 architecture based devices, ROM supports boot only via MCU(R5). This means that bootloader has to run on R5 core. In order to meet this constraint, keeping safety in picture and to have faster boot time, the software boot architecture is designed as below:
+------------------------------------------------------------------------+
| DMSC | R5 | ARM64 |
+------------------------------------------------------------------------+
| +--------+ | | |
| | Reset | | | |
| +--------+ | | |
| : | | |
| +--------+ | +-----------+ | |
| | *ROM* |----------|-->| Reset rls | | |
| +--------+ | +-----------+ | |
| | | | : | |
| | ROM | | : | |
| |services| | : | |
| | | | +-------------+ | |
| | | | | *R5 ROM* | | |
| | | | +-------------+ | |
| | |<---------|---|Load and auth| | |
| | | | | tiboot3.bin | | |
| | | | +-------------+ | |
| | | | : | |
| | | | : | |
| | | | : | |
| | | | +-------------+ | |
| | | | | *R5 SPL* | | |
| | | | +-------------+ | |
| | | | | Load | | |
| | | | | sysfw.itb | | |
| | Start | | +-------------+ | |
| | System |<---------|---| Start | | |
| |Firmware| | | SYSFW | | |
| +--------+ | +-------------+ | |
| : | | | | |
| +---------+ | | Load | | |
| | *SYSFW* | | | system | | |
| +---------+ | | Config data | | |
| | |<--------|---| | | |
| | | | +-------------+ | |
| | | | | | | |
| | | | | DDR | | |
| | | | | config | | |
| | | | +-------------+ | |
| | | | | | | |
| | |<--------|---| Start A53 | | |
| | | | | and Reset | | |
| | | | +-------------+ | |
| | | | | +-----------+ |
| | |---------|-----------------------|---->| Reset rls | |
| | | | | +-----------+ |
| | DMSC | | | : |
| |Services | | | +-----------+ |
| | |<--------|-----------------------|---->|*ATF/OPTEE*| |
| | | | | +-----------+ |
| | | | | : |
| | | | | +-----------+ |
| | |<--------|-----------------------|---->| *A53 SPL* | |
| | | | | +-----------+ |
| | | | | | Load | |
| | | | | | u-boot.img| |
| | | | | +-----------+ |
| | | | | : |
| | | | | +-----------+ |
| | |<--------|-----------------------|---->| *U-Boot* | |
| | | | | +-----------+ |
| | | | | | prompt | |
| | | | | +-----------+ |
| +---------+ | | |
| | | |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| TIFS | Main R5 | A53 |
+------------------------------------------------------------------------+
| +--------+ | | |
| | Reset | | | |
| +--------+ | | |
| : | | |
| +--------+ | +-----------+ | |
| | *ROM* |----------|-->| Reset rls | | |
| +--------+ | +-----------+ | |
| | | | : | |
| | ROM | | : | |
| |services| | : | |
| | | | +-------------+ | |
| | | | | *R5 ROM* | | |
| | | | +-------------+ | |
| | |<---------|---|Load and auth| | |
| | | | | tiboot3.bin | | |
| +--------+ | +-------------+ | |
| | |<---------|---| Load sysfw | | |
| | | | | part to TIFS| | |
| | | | | core | | |
| | | | +-------------+ | |
| | | | : | |
| | | | : | |
| | | | : | |
| | | | +-------------+ | |
| | | | | *R5 SPL* | | |
| | | | +-------------+ | |
| | | | | DDR | | |
| | | | | config | | |
| | | | +-------------+ | |
| | | | | Load | | |
| | | | | tispl.bin | | |
| | | | +-------------+ | |
| | | | | Load R5 | | |
| | | | | firmware | | |
| | | | +-------------+ | |
| | |<---------|---| Start A53 | | |
| | | | | and jump to | | |
| | | | | DM fw image | | |
| | | | +-------------+ | |
| | | | | +-----------+ |
| | |----------|-----------------------|---->| Reset rls | |
| | | | | +-----------+ |
| | TIFS | | | : |
| |Services| | | +-----------+ |
| | |<---------|-----------------------|---->|*ATF/OPTEE*| |
| | | | | +-----------+ |
| | | | | : |
| | | | | +-----------+ |
| | |<---------|-----------------------|---->| *A53 SPL* | |
| | | | | +-----------+ |
| | | | | | Load | |
| | | | | | u-boot.img| |
| | | | | +-----------+ |
| | | | | : |
| | | | | +-----------+ |
| | |<---------|-----------------------|---->| *U-Boot* | |
| | | | | +-----------+ |
| | | | | | prompt | |
| | |----------|-----------------------|-----+-----------+-----|
| +--------+ | | |
| | | |
+------------------------------------------------------------------------+
Here TIFS acts as master and provides all the critical services. R5/ARM64 requests TIFS to get these services done as shown in the above diagram.