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Description
Description
Memory protection is enabled by default by MPU API #8335.
This change increased my code size by 824 bytes. The target is an STM32L442 and this is using the develop profile.
I tried to disable the MPU API but found it still added 406 bytes.
Here's a bit more detail...
| Module | .text | .data | .bss |
|--------------------------------------------------------|--------------|----------|-----------|
...
| mbed-os\hal\mpu\mbed_mpu_v7m.o | 315(+315) | 0(+0) | 0(+0) |
...
| mbed-os\platform\mbed_mpu_mgmt.o | 446(+446) | 0(+0) | 4(+4) |
| Subtotals | 215926(+824) | 3296(+0) | 28488(+0) |
...
Total Static RAM memory (data + bss): 31784(+0) bytes
Total Flash memory (text + data): 219222(+824) bytes
I can reduce the code size by defining MBED_MPU_CUSTOM
and removing the MPU device from my custom target:
| Module | .text | .data | .bss |
|--------------------------------------------------------|--------------|----------|-----------|
...
| mbed-os\hal\mpu\mbed_mpu_v7m.o | 0(-315) | 0(+0) | 0(+0) | ...
...
| mbed-os\platform\mbed_mpu_mgmt.o | 406(-40) | 0(+0) | 4(+0) |
...
| Subtotals | 215590(-336) | 3296(+0) | 28488(+0) |
Total Static RAM memory (data + bss): 31784(+0) bytes
Total Flash memory (text + data): 218886(-336) bytes
Memory protection is important but it probably should be possible to disable it and it have zero impact(?).
My original comment is here: #8335 (comment)
Issue request type
[ ] Question
[ ] Enhancement
[X] Bug