4.45. Embedded Software Startup

4.45.1. Module Files

4.45.1.1. Driver

• src/app/main/fstartup.c

• src/app/main/include/fstartup.h

4.45.1.2. Configuration

none

4.45.1.3. Unit Test

• tests/unit/app/main/test_fstartup.c

4.45.2. Description

The startup code begins in the function _c_int00() in app/main/fstartup.c. After initialization of the main microcontroller registers, memory, system clock and interrupts, the C function main() is called. In general/main.c, interrupts are enabled and the initializations of the microcontroller unit, peripherals and software modules are done (e.g., hardware modules like SPI and DMA). The OS is then started. The steps are indicated by the global variable os_boot. At the end of the main function, the operating system resources (tasks, queues) are configured in OS_InitializeOperatingSystem() (src/app/task/os/os.c) and the scheduler is started. All configured tasks (FreeRTOS threads) are then started depending on their priority. The successful activation of the tasks is indicated by os_boot = OS_RUNNING.

The OS-scheduler first calls the highest priority task. All other cyclic tasks are blocked in a while-loop until the initialization of this task finishes. At the beginning of the task, FTSK_InitializeUserCodeEngine() is called. In this function, the database is initialized. Once finished, this is indicated by os_boot = OS_ENGINE_RUNNING. The function FTSK_RunUserCodeEngine() is then called, where the diagnostic module and the database are managed.

Once os_boot = OS_ENGINE_RUNNING, the 1ms Task is unblocked. The function FTSK_InitializeUserCodePreCyclicTasks() is called once first. This function is called when the OS and the database are running but before the cyclic tasks run. Once FTSK_InitializeUserCodePreCyclicTasks() has finished, all cyclic tasks are unblocked from there while-loop and run periodically.