Certain read causes hang/crash

[Hedley]

Reading this cell: 0xe0040000 will hard crash the CPU. You can do it from non secure code also, which opens the way for a possible denial of service attack.

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I​n gdb:

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x​/x 0xe0040000

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I​ realize parallel trace (the tpiu reg in Q) is not implemented but at least return 0, dont hang.

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Only a power cycle can recover it. Soft reset is insufficient.

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T​nx

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H.​

[Hedley]

Operator error. That space @0xe0040000 cannot be read unless... some bits are flipped.

SWO trace works now.

   DBGMCU_Periph.CR.TRACE_EN := True;

   DBGMCU_Periph.CR.TRACE_IOEN := True;

where:

  DBGMCU_Periph : aliased DBGMCU_Peripheral

   with Import, Address => System'To_Address (16#E0044000#);