[Qemu-devel] [Bug 696094] Re: TI Stellaris lm3s811evb (ARM Cortex-M3) : Systick interrupt not working

[ARUNKUMAR VASUDEVAN <696094@bugs.launchpad.net>]

** Changed in: qemu
       Status: New => Incomplete

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Title:
  TI Stellaris lm3s811evb (ARM Cortex-M3) : Systick interrupt not
  working

Status in QEMU:
  Incomplete

Bug description:
  I've tried to create a small project that uses the CMSIS as base library.
  The problem is that the SysTick_interrupt_handler() doesn't get executed when the systick event is detected in QEMU. Furthermore, it seems asif QEMU gets stuck in an endless loop. QEMU doesn't respond to Ctrl-C on the command line and the GDB session also stalls. 'kill -9' is the only way to stop QEMU.

  It seems asif the initialisation of the NVIC works fine. I've traced the function calls in QEMU as follows:
  stellaris.c: stellaris_init() - Perform generic armv7 init: armv7m_init()
     armv7m.c: armv7m_init() - Create and init the nvic:
                                 nvic = qdev_create(NULL, "armv7m_nvic");
                                 env->nvic = nvic;
                                 qdev_init_nofail(nvic);
                             - Configure the programmable interrupt controller:
                                 Call: arm_pic_init_cpu() 
                                          qemu_allocate_irqs(arm_pic_cpu_handler)
                             - Initialise 64 interrupt structures.

  The following call sequence is observed when the systick event occur:
  armv7m_nvic.c: systick_timer_tick(): set pending interrupt
  armv7m_nvic.c: armv7m_nvic_set_pending() for irq:15
    arm_gic.c: gic_set_pending_private(): GIC_SET_PENDING(15,)
      arm_gic.c: gic_update() - Raise IRQ with qemu_set_irq()
         irq.c: eqmu_set_irq() - Call the irq->handler 
                                 -- I assume the irq handler is 'arm_pic_cpu_handler()',
                                    since that was passed as the parameter when
                                    qemu_allocate_irqs() was called in ...
            arm_pic.c: arm_pic_cpu_handler() - After evaluation, call cpu_interrupt()
               exec.c: cpu_interrupt() is called.     

  The tools that were used during the testing of this project:
    GCC: Codesourcery ARM eabi 2010q3
    QEMU: Checked out on 31/12/2010 - Last commit: 0fcec41eec0432c77645b4a407d3a3e030c4abc4
  The project files are attached, for reproducing of the errors.
     Note: The CMSIS wants to perform byte accesses to the NVIC. For the Cortex-M3, unaligned 8 bit and 16 bit accesses are allowed. The current QEMU implementation doesn't yet cater for it. As a work around, updated versions of
  arm_gic.c armv7m_nvic.h armv7m_nvic.c is also included.

  Launch project with: go_gdb.sh
  Attach debugger with: arm-none-eabi-gdbtui --command=gdbCommands_tui
  (s = step, n = next, c = continue, Ctrl-C = stop, print <variable> to look at variable contents)

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