Files
micropython/ports/qemu-arm
Damien George 69c25ea865 shared/runtime/pyexec: Make a raised SystemExit always do a forced exit.
The current situation with SystemExit and soft reset is the following:
- `sys.exit()` follows CPython and just raises `SystemExit`.
- On the unix port, raising `SystemExit` quits the application/MicroPython,
  whether at the REPL or in code (this follows CPython behaviour).
- On bare-metal ports, raising `SystemExit` at the REPL does nothing,
  raising it in code will stop the code and drop into the REPL.
- `machine.soft_reset()` raises `SystemExit` but with a special flag set,
  and bare-metal targets check this flag when it propagates to the
  top-level and do a soft reset when they receive it.

The original idea here was that a bare-metal target can't "quit" like the
unix port can, and so dropping to the REPL was considered the same as
"quit".  But this bare-metal behaviour is arguably inconsistent with unix,
and "quit" should mean terminate everything, including REPL access.

This commit changes the behaviour to the following, which is more
consistent:
- Raising `SystemExit` on a bare-metal port will do a soft reset (unless
  the exception is caught by the application).
- `machine.soft_reset()` is now equivalent to `sys.exit()`.
- unix port behaviour remains unchanged.

Tested running the test suite on an stm32 board and everything still
passes, in particular tests that skip by raising `SystemExit` still
correctly skip.

Signed-off-by: Damien George <damien@micropython.org>
2024-07-20 12:13:14 +10:00
..

This is experimental, community-supported port for Cortex-M emulation as provided by QEMU (http://qemu.org).

The purposes of this port are to enable:

  1. Continuous integration
    • run tests against architecture-specific parts of code base
  2. Experimentation
    • simulation & prototyping of anything that has architecture-specific code
    • exploring instruction set in terms of optimising some part of MicroPython or a module
  3. Streamlined debugging
    • no need for JTAG or even an MCU chip itself
    • no need to use OpenOCD or anything else that might slow down the process in terms of plugging things together, pressing buttons, etc.

This port will only work with the [GNU ARM Embedded Toolchain]( https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads and not with CodeSourcery toolchain. You will need to modify LDFLAGS if you want to use CodeSourcery's version of arm-none-eabi. The difference is that CodeSourcery needs -T generic-m-hosted.ld while ARM's version requires --specs=nano.specs --specs=rdimon.specs to be passed to the linker.

To build and run image with builtin testsuite:

make -f Makefile.test test