AUTOSAR overview: BSW, RTE, SWC

The standard structure of automotive software. The RTE connects the BSW, close to the hardware, with the SWCs that hold the functions.

Layers

The layers of AUTOSAR Classic. Application software sees only the RTE and knows nothing of the hardware.

Layer	Contents
SWC (application)	Function logic. Knows nothing about the hardware
RTE	Connects SWC to SWC and SWC to BSW with generated code
BSW services	Communication (COM, PduR), diagnostics (DCM, DEM), memory (NvM), OS
ECU abstraction	Hides the board configuration
MCAL	MCU drivers (DIO, ADC, PWM, CAN)

How the work goes

In system design, define the SWCs and their ports (the data they exchange) in ARXML
Configure the BSW modules with tools (Vector DaVinci, EB tresos)
Generate the RTE and BSW code
The developer writes logic inside the SWC's runnables (functions called periodically)

void SpeedCtrl_Run10ms(void) {
    uint16 spd;
    Rte_Read_VehSpd_Value(&spd);
    Rte_Write_TrqReq_Value(calc_torque(spd));
}

Classic and Adaptive

Classic: MCUs, static configuration, real-time ECUs
Adaptive: high-performance SoCs, POSIX OS, service-oriented communication (SOME/IP), dynamic deployment

In industry, ASW development mostly handles SWC logic (in many cases code generated from Simulink models), and BSW development handles the configuration and integration of communication, diagnostics and drivers.