It both reduces flash size and move symbols to read-only sections.
The scheduler_tasks table is one known not to be in read-only section before due
to the FastDelegate implementation. Before and after this patch:
ArduPlane $ size ArduPlane.elf{.old,}
text data bss dec hex filename
733368 8252 67352 808972 c580c ArduPlane.elf.old
730632 8236 64792 803660 c434c ArduPlane.elf
ArduPlane $ nm -C ArduPlane.elf.old|grep scheduler_tasks
0000000000402800 t _GLOBAL__sub_I__ZN5Plane15scheduler_tasksE
00000000006b54c0 B Plane::scheduler_tasks
ArduPlane $ nm -C ArduPlane.elf|grep scheduler_tasks
0000000000490900 R Plane::scheduler_tasks
As can be seen above, now the scheduler_tasks symbol is in a read-only data
section and in all of them we decreased the total size.
For APM2 we have a little increase in the text size size.
ArduPlane $ size ArduPlane.elf{.old,}
text data bss dec hex filename
241940 942 4447 247329 3c621 ArduPlane.elf.old
242222 942 4431 247595 3c72b ArduPlane.elf
ArduPlane $ nm -C ArduPlane.elf.old|grep scheduler_tasks
00001f8f T Plane::scheduler_tasks
ArduPlane $ nm -C ArduPlane.elf|grep scheduler_tasks
00001f8f T Plane::scheduler_tasks
It both reduces flash size and move symbols to read-only sections.
The scheduler_tasks table is one known not to be in read-only section before due
to the FastDelegate implementation. Before and after this patch:
APMrover2 $ size APMrover2.elf{.old,}
text data bss dec hex filename
611406 4832 40920 657158 a0706 APMrover2.elf.old
609686 4824 38936 653446 9f886 APMrover2.elf
APMrover2 $ nm -C APMrover2.elf{.old,} |grep tasks
0000000000696f80 B Rover::scheduler_tasks
000000000047c440 R Rover::scheduler_tasks
As can be seen above, now the scheduler_tasks symbol is in a read-only data
section and in all of them we decreased the total size.
For APM2 we have a similar situation, but the table was already in text section
because it was using plain C pointers:
APMrover2 $ size APMrover2.elf{.old,}
text data bss dec hex filename
189518 1038 3494 194050 2f602 APMrover2.elf.old
189216 1038 3480 193734 2f4c6 APMrover2.elf
APMrover2 $ nm -C APMrover2.elf{.old,} |grep tasks
00001f92 T Rover::scheduler_tasks
00001f8a T Rover::scheduler_tasks
Start to add code behind APM_BUILD_FUNCTOR to support changing the
functor implementation (without breaking the build while the change is
not complete).
Andrew Tridgell
Lucas De Marchi
Michael du Breuil
Andrew Tridgell
Randy Mackay