• Locked Locked
  • Replies 4 replies
  • Subscribers 121 subscribers
  • Views 5490 views
  • Users 0 members are here
2025 survey

We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.

Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

What's mean that CMD440-COR182-TAD23-NAL29

amaolei

Hi All,

When I was debugging arm926ej-s using DS-5, DS-5 stoped as soon as enable MMU and output CMD440-COR182-TAD23-NAL29.

What mean is it?

Parents
  • Arm Employee Badge in reply to amaolei

    There are two possibilities:

    1) enabling the MMU changes the virtual/physical address the core is running at

    2) enabling the MMU changes the permissions at the virtual address the core is running at

    the second is most likely but be aware of the first.

    if your MMU setup marks the range where you're trying to step as read-only you can't set a breakpoint there anymore, which is how pre-v8 cores handle stepping.

    try before you start stepping:

    memory 0xXXXXXX +0xYYY ro,nobp,hbp 

    Where the two numbers are the start and length of the read-only range. Generally it is advised that stepping into MMU enable isn't really possible (because the debugger is executing instructions via the core in the core's context and it changes).

    You could set a breakpoint (hardware based if it's read only memory) past the MMU enable and run through it, though.

    Matt

Reply
  • Arm Employee Badge in reply to amaolei

    There are two possibilities:

    1) enabling the MMU changes the virtual/physical address the core is running at

    2) enabling the MMU changes the permissions at the virtual address the core is running at

    the second is most likely but be aware of the first.

    if your MMU setup marks the range where you're trying to step as read-only you can't set a breakpoint there anymore, which is how pre-v8 cores handle stepping.

    try before you start stepping:

    memory 0xXXXXXX +0xYYY ro,nobp,hbp 

    Where the two numbers are the start and length of the read-only range. Generally it is advised that stepping into MMU enable isn't really possible (because the debugger is executing instructions via the core in the core's context and it changes).

    You could set a breakpoint (hardware based if it's read only memory) past the MMU enable and run through it, though.

    Matt

Children