The Mediatek MT6253 is a relatively modern baseband SoC made by Taiwan-based Mediatek.
It inherits a lot from the older series of MT622x SoCs, but provides 2 DSP cores, RF module and power management block on the chip.
The chip uses different addresses for periph. bus compared to it's predecessors.
2G RF "chip" is called MTKSOC1 (connected directly to BSI).
The chip contains ROM bootloader similar to MT6253.
In order to keep the chip powered-on, PMIC registers need to be set-up properly.
Baseband communication is handled by DSP #1424.
- Power ON DSP
- Install patch data
- Write some data via IDMA
- Wait for correct data in DSP1_SharedMem
Communication between ARM and DSP is carried via DSP1 Shared memory region and DSP1 shared registers. Initialization uses also IDMA.