Without resetting the FPU we get spurious failures in Pycardium.  These
manifest in many different forms, ranging from HardFaults and triggered
assertions to "syntax errors" in loaded scripts while said script does
not contain any.

These failures stem from the FPU still containing state from the last
loaded payload and thus sometimes corrupting stack locations where the
previous payload had floating point state.

Closes #72.

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Co-authored-by: fleur <spacecarrot@fleurshax.net>
Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

This adds BLE a characteristic which allows to set the current time. The
time is set in milliseconds since 1.1.1970 as 64 bit value.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

This allows to set the current time in milliseconds.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

The new LEDs implementation already does gamma correction so it is
unnecessarily duplicated here now.  This commit also adds a short hello
message on the serial and sets the dim factor for the LEDs to a value
where the LED effect is more visible.

Signed-off-by: Rahix <rahix@rahix.de>

When a load fails early and core 1 continues to loop in the reset stub,
Epicardium might lock up when sending an interrupt and waiting for the
API_CALL_MEM->int_id to be reset.

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

swym authored 5 years ago and rahix committed 5 years ago

This commit adds 3 new API calls

- epic_file_opendir()
- epic_file_readdir()
- epic_file_unlink()

and 2 new functions in Pycardium

- os.listdir()
- os.unlink()

This changeset implements a proper lifecycle of the core 1 payload.
The implementation faces some difficulties because there is no way to
properly reset just core 1.  Instead, we chose a cooperative approach:

To perform a reset, core 1 jumps to a reset-stub and is then fed a new
IVT location which it uses to "restart" with a new payload.  The jump to
the reset-stub is either voluntary by a call to epic_exit() or epix_exec(),
or involuntary by Epicardium issuing a "reset" interrupt.  This is a
special API interrupt whose handler is pre-implemented in the API-caller
lib.

Additionally, this changeset contains support for defining which python
script Pycardium should execute on startup.  This way, scripts can issue
the start of one another using `epic_exec("script-name.py")`.

Finally, this changeset also changes the power-button behavior.
Pressing the power button will now excert the following behavior:

    - `<400 ms`: Return back to menu
    - `<1 s`: Reset card10
    - `>1 s`: Poweroff

Signed-off-by: Rahix <rahix@rahix.de>

This adds basic file transfer support over BLE.

The central provides a filename and then can transfer chunks of data
which are written to the file.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

Pressing the power button will now excert the following behavior:

- `<400 ms`: Return back to menu
- `<1 s`: Reset card10
- `>1 s`: Poweroff

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

This commit introduces a lifecycle for core 1.  Based on the new loading
system, a few APIs are made available to control the payload running on
core 1.  These are:

1. From core 1 (Pycardium, L0dable):

    - `epic_exec(name)` API Call:  Request loading of a new payload by
      name.  If the file does not exist, the call will return with an
      error code.  Otherwise, control will go to the new payload.
    - `epic_exit(retcode)` API Call:  Return from payload
      unconditionally.  This call should be called whenever a payload is
      done or when it has hit an unrecoverable error.  On `epic_exit`,
      Epicardium will reset the core back into the menu.

2. From inside Epicardium:

    - `epic_exec(name)`: This is **not** the same as the API call, as it
      needs a different implementation underneath.  It will load a new
      payload and wait until this load actually completed (synchroneous).
    - `return_to_menu()`: Return core 1 to the menu script no matter
      what it is currently doing.  This call is asynchroneous and will
      return immediately after scheduling the lifecycle task.  This task
      will then take care of actually performing the load.

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Also add a mutex around API calls in preparation for future changes.

Signed-off-by: Rahix <rahix@rahix.de>

This commit introduces a way to control core 1.  This is archieved by a
predefined API-Interrupt:  The reset interrupt.  When triggered, it will
bring the core back into its default state and wait for a new vector
address from Epicardium.  Once this vector address is transferred, it
will start the new payload.

This method only works as long as core 1 is responsive to the API
interrupts.  Cases where this might not be the case:

  - During times where core 1 has interrupts disabled
  - When in a higher priority exception handler
  - When core 1 has corrupted its IVT

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Previously 0 was used but as 0 is also the ID of the reset interrupt,
this could lead to weird behaviors.

Signed-off-by: Rahix <rahix@rahix.de>

This allows pycardium to learn which script it should start once it
boots.  Arguments can only be read before any API calls are made.
Afterward they are lost.

To ensure they won't collide with anything during a core 1 restart,
they are offset by 0x20 from the start of the API buffer.

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

By default the MTU is set to 23 bytes, use 241 bytes instead to make the
UART and file transfer service more efficient. The MTU also contains
some BLE headers and is not only the usable data.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

The vector table's alignment requirements depend on the number of
interrupts [1].  In our case, we have 0x6E(=110) interrupts and thus an
alignment requirement of 0x80(=128).

To satisfy this requirement, this commit moves the IVT to the beginning
of .text and enforces a 128 byte alignment.  Please note that the
headers which come before .text will push the IVT to 0x100 instead of
having it directly in the beginning at 0x00.

[1]: https://developer.arm.com/docs/dui0553/a/cortex-m4-peripherals/system-control-block/vector-table-offset-register



Signed-off-by: Rahix <rahix@rahix.de>