Allocate per-instance data for drivers from the heap
rather than as static variables from the .data segment.
This converts > 800 bytes of RAM from being always consumed
as static data into being allocated from the heap only when
a particular feature is enabled in the hwsettings object.
A minimal config (no receivers, flexi port disabled, main port
disabled) leaves 2448 bytes of free heap. That's our new baseline.
Approximate RAM (heap) costs of enabling various features:
+ 632 Serial Telemetry (includes 400 bytes of Rx/Tx buffers)
+ 108 PWM Rcvr
+ 152 PPM Rcvr
+ 112 Spektrum Rcvr
+ 24 S.Bus (Should be closer to 68 since driver is still using
static memory)
There are still some drivers that pre-allocate all of their memory
as static data. It'll take some work to convert those over to
dynamically allocating their instance data.
PWM and PPM can now coexist in the same load and be
selected at boot time via the hwsettings UAVObject.
This is basically a complete restructuring of the
way the drivers interact with the TIM peripheral in
the STM32.
As a side effect, the PWM and PPM drivers are now
ready to support multiple instances of each.
This also provides the first step toward being able
to reassign some of the PWM input pins to be servo
output pins. Still more work required, but this is
a good start.
This allows the spektrum and sbus receiver drivers to bind
directly to the usart layer using a properly exported API
rather than overriding the interrupt handler.
Bytes are now pushed directly from the usart layer into the
com layer without any buffering. The com layer performs all
of the buffering.
A further benefit from this approach is that we can put all
blocking/non-blocking behaviour into the COM layer and not
in the underlying drivers.
Misc related changes:
- Remove obsolete .handler field from irq configs
- Adapt all users of PIOS_COM_* functions to new API
- Fixup callers of PIOS_USB_HID_Init()
Each channel was previously tracking a separate driver.
Now, channels are grouped within a channel group to save
RAM used for tracking and to better reflect how channels
are actually mapped.
All receivers now fall under the same driver API provided
by pios_rcvr.c.
This is part of a larger sequence of commits that will
switch the receiver selection over to boot time dynamic
configuration via UAVObjects.
Beginning of unifying the input types into PIOS_RECEIVER.
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@2568 ebee16cc-31ac-478f-84a7-5cbb03baadba
priority preempts) and adjusting the priorities around to be more sensible.
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@2355 ebee16cc-31ac-478f-84a7-5cbb03baadba
Added timer usage diagram to pios_board.h
Removed bloat for extra optimisation in PIOS_DELAY.
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@265 ebee16cc-31ac-478f-84a7-5cbb03baadba
Added PIOS_USB.
Global improvements, see specific files for changes.
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@144 ebee16cc-31ac-478f-84a7-5cbb03baadba
