Trouble understanding GNU

Discussion in 'Embedded Systems and Microcontrollers' started by corsair, Apr 17, 2010.

  1. corsair

    Thread Starter Member

    Mar 6, 2010
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    Hi Guys,

    So I'm coming from the PIC world of uC's and taking a step into the ARM world. My professor asked me to build this under gnu-elf-as. I understand that this is a file under the "yagarto" toolchain, but I don't really understand what it is. From the PIC perspective, all I did was write some code, and push "Make All" and everything was simple. Now, I'm confused with all these terms like GCC, GNU, Elfs (hehe).

    I know that the reason GNU is so popular is because it's free and GCC is the compiler. But what's the reason for needing to use "gnu-elf-as?" Will it compile differently as opposed to not using it?

    Also, if anyone have any LPC2368 source code built under gnu-elf-as, it would help a lot! I've been searching Google left and right, and it seems like all I can find is C code. As always, thanks for your help :)
     
  2. bertus

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    Apr 5, 2008
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    corsair likes this.
  3. corsair

    Thread Starter Member

    Mar 6, 2010
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    Thank you Bertus. Do you (or anyone else) happen to know why JTAG is so important with ARMs? They don't have this in PIC uC's I don't think. Why would you need hardware debugging over a simulation debug? (Aside from terrible saudering)
     
  4. bertus

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  5. corsair

    Thread Starter Member

    Mar 6, 2010
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    Sorry, call me dumb, but I still don't see it's advantages over software simulation. Can you explain in your own words please?

    On the wiki, JTAG can do halt mode and monitor mode. I think every IDE I've worked with has a "step" button with its debug mode and can view the data in the registers. In addition, the JTAG can visibly "see" every piece of data that's running in the hardware. So what? The advantage still isn't clear to me. I am seeing it more as a disadvantage due to the extra equipment you need to purchase.

    My questions still remain:
    -Why JTAG is so important with ARMs?
    -Why would you need hardware debugging over software debugging?
     
  6. bertus

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    Apr 5, 2008
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