Forum Post: Calling the bootloader I2C update handler from TI-RTOS application

My config: using TM4C123BH, IAR v6.70, TI-RTOS 2.0.0.22, TivaWare 2.1.0.12573c

I'm using a custom bootloader based on TivaWare in my FLASH area 0x0000000-0x00001FFF. The application starts at 0x00002000. The boot up is working fine, the bootloader detects a valid application and starts the application with TI-RTOS. TI-RTOS also is working fine (I'm using GPIO, ADC, I2C Master, I2C Slave, Timers, Hwi and Swi, Semaphores, Events, Gates, 6 different Tasks). For firmware update I need to call the bootloader from my application. The command for firmware update is received by the I2C slave interface. I jump to the bootloader using the following code:

        // We must make sure we turn off SysTick and its interrupt before entering
        // the boot loader!
        ROM_SysTickIntDisable();
        ROM_SysTickDisable();

        // Disable all processor interrupts.  Instead of disabling them
        // one at a time, a direct write to NVIC is done to disable all
        // peripheral interrupts.
        HWREG(NVIC_DIS0) = 0xffffffff;
        HWREG(NVIC_DIS1) = 0xffffffff;

        // Load the stack pointer from the bootloader's vector
        __set_MSP( *((volatile uint32_t*)0x00 ));

        // Return control to the boot loader.  This is a call to the
        // SVC UpdateHandler in the boot loader and should never return.
        // If it does, very bad things will likely happen.
        (*((void (*)(void))(*(uint32_t *)0x2c)))();

The bootloader call also works, it is displayed by a GPIO (LED). But the update handler using the I2C slave interface stucks. The I2C address byte is acknowledged, but further data will not acknowledged any I get a timeout.

If I start the bootloader update handler without TI-RTOS application, everything is working fine. So I guess, something must be disabled in the application before the bootloader is called. Any ideas?