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project:arm_debugging:start [2019/12/22 16:26] – [Example: Unbricking (restoring) Proxmark bootloader] abyssalproject:arm_debugging:start [2021/06/05 19:29] (current) – [Example: Unbricking (restoring) Proxmark bootloader] Flash bootloader and fullimage from same build abyssal
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 </code> </code>
  
 +Seems that flashing bootloader may not be enough, flash bootloader.elf and fullimage.elf from the same build in a single session (e.g. use ''file'' command in gdb), since mixing different branches may still result in bricked proxmark. Some bootloaders can't load fullimages built from other branches.
 ===== J-link connected to Proxmark ===== ===== J-link connected to Proxmark =====
  
 {{ :project:proxmark-jlink.jpg?800 | }} {{ :project:proxmark-jlink.jpg?800 | }}
  
 +===== SystemView for J-link - visualization of interrupts or other functions =====
  
 +There is an instrumentation possible with changes to code to show how your functions and interrupts behave - [[https://wiki.segger.com/Use_SystemView_without_RTOS | sample code]]
 +
 +Here is an example showing "tail chaining" of interrupts where interrupts are behind one another, and also "late arriving", where Systick interrupts USB interrupt (marked as IST #93 starting at position 2195):
 +
 +{{:project:arm_debugging:systemview_20200318_113539.png?800|}}
 +
 +If you add extra functions, it may measure your functions as well:
 +
 +{{:project:arm_debugging:systemview_20200318_100652.png?800|}}
 +
 +As a side note, ST-link on STM32 discovery boards can be reflashed to JLink (works only on discovery boards, not on separate ST-links).
 +
 +===== ARM ETM trace - recording executed instructions =====
 +
 +ARM processors (Cortex M1+ and others) have built-in a nifty feature that you can record all instructions executed. This requires quite costly hardware (expect 2000 EUR price - JTrace, Lauterbach and uLink), but it can be handy in debugging DMA and interrupts.
 +
 +An example ETM trace:
 +
 +{{:project:arm_debugging:ozone_error_shutdown_highlighted.png?800|}}
 +
 +===== ARM ITM trace - recording samples of executed instructions, interrupts =====
 +
 +You can get code profile like this with ITM (screenshow from ''orbtop''):
 +
 +{{:project:arm_debugging:orbtop_trezor_lots_of_segwit_inputs.png|}}
 +
 +To get this working, [[https://github.com/hiviah/ITM-howto-JLink-STLink|follow this howto]]. It shows steps to be used with JLink/JTrace or STLink to get it moving.
 ====== Flyswatter connected to Proxmark ====== ====== Flyswatter connected to Proxmark ======
  
project/arm_debugging/start.1577032017.txt.gz · Last modified: 2019/12/22 16:26 by abyssal