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--- project:arm_debugging:start [2019/12/20 21:24] – [BMP PC-hosted with unmodified STLink target] abyssal
+++ project:arm_debugging:start [2021/06/05 19:29] (current) – [Example: Unbricking (restoring) Proxmark bootloader] Flash bootloader and fullimage from same build abyssal
@@ Line 303: / Line 303: @@
 This is happening mostly on cheap clones of proxmark3 Easy.
+To debug Proxmark on newer OpenOCD >= 0.10.0, you may set fast memory access and fast DCC downloads:
+<code>
+openocd -c "adapter_khz 4000" -f interface/jlink.cfg -c "gdb_memory_map disable" -f target/at91sam7x256.cfg -c "init; arm7_9 fast_memory_access enable; arm7_9 dcc_downloads enable"
+</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 =====
 {{ :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 ======
@@ Line 510: / Line 542: @@
 <code>
-PROBE_HOST=stlink ST_BOOTLOADER=1
+make PROBE_HOST=stlink ST_BOOTLOADER=1
 </code>