Commit Graph

2 Commits

Author SHA1 Message Date
Jakob Hasse
e32831033a [esp_rom]: fixed S3 longjmp patch
* On S3, the placement of ROM functions is
  ECO-dependent. Hence, we don't jump into
  the middle of the longjmp function in ROM
  on S3 anymore.
  Instead, the whole longjump function is used
  in the patch.

* Also properly excluded the patch from
  bootloader build with Makefiles

Closes IDF-3391
2021-06-18 15:47:41 +08:00
Jakob Hasse
fc22e3c645 [system]: Made longjmp save for context switch
* Patched longjmp to be context-switch safe
  longjmp modifies the windowbase and windowstart
  registers, which isn't safe if a context switch
  occurs during the modification. After a context
  switch, windowstart and windowbase will be
  different, leading to a wrongly set windowstart
  bit due to longjmp writing it based on the
  windowbase before the context switch. This
  corrupts the registers at the next window
  overflow reaching that wrongly set bit.

  The solution is to disable interrupts during
  this code. It is only 6 instructions long,
  the impact shouldn't be significant.

  The fix is implemented as a wrapper which
  replaces the original first instructions of
  longjmp which are buggy. Then, it jumps back
  to execute the rest of the original longjmp
  function.

  Added a comparably reliable test to the
  test apps.
2021-04-23 15:55:31 +08:00