13022591351 opened a new pull request, #19983:
URL: https://github.com/apache/nuttx/pull/19983
## Summary
* Make STM32H7 Protected user heap placement consistently use `SRAM_END`,
which represents the primary SRAM selected for the active M7/M4 chip
configuration.
* Remove the fixed `SRAM123_END` placement that is inconsistent with heap
sizing and is undefined for dual-core M7 and M4 configurations.
* Map Protected user data and heap SRAM as Normal, cacheable, and
non-shareable so LDREX/STREX synchronization uses the CPU-local exclusive
monitor on STM32H7.
* Keep dual-core RPTUN SRAM unaffected: its shared region is mapped
separately
with explicit shareable attributes.
## Impact
* New feature: **NO**. This fixes STM32H7 Protected memory placement and MPU
attributes.
* User adaptation: **NO**.
* Build process: **NO**.
* Hardware: **YES**. Only STM32H7 Protected builds are affected. Flat builds
are unchanged. Dual-core shared RPTUN SRAM keeps its existing mapping.
* Documentation: Public API documentation is not affected; source comments
document the mapping and dual-core exception.
* Security: **NO** reduction in privilege separation. User access permissions
remain `P:RW/U:RW`; only the SRAM memory attributes change.
* Compatibility: The Protected user heap now resides in the SRAM region
selected by the board/chip configuration instead of a fixed D2 boundary.
## Testing
Build host:
* Linux 6.8.0-60-generic, x86_64
* GNU Arm Embedded Toolchain 10.3.1 20210824
Target:
* ARM Cortex-M7, STM32H7, PX4 FMUv6C
* Apache NuttX master `850805d70c88b0d63d4364d7110ce5363d2448ee`
* Protected user heap in AXI SRAM, write-through data cache enabled
Build output:
```text
Protected kernel:
kflash 877528 B / 896 KB (95.64%)
ksram 54320 B / 128 KB (41.44%)
Protected user:
uflash 751000 B / 1 MB (71.62%)
usram 8192 B / 384 KB (2.08%)
```
Runtime stress results:
```text
Protected libc user WQ: 15.6540 / 15.6540 / 15.6540 s
Protected kernel WQ: 30.1490 / 30.1480 / 30.1480 s
Steady current memory after initial run:
Kmem used/free: 10104 / 243848 B
Umem used/free: 9232 / 416752 B
```
The tests repeatedly exercised pthread creation, mutex/semaphore atomics,
multi-worker queues, synchronous cancellation, and queue teardown. All runs
completed without assertion, fault, residual worker, or cumulative Kmem/Umem
growth. The board cold-booted into NSH and remained stable.
Validation:
```text
tools/checkpatch.sh -m -g upstream/master..fix/stm32h7-protected-memory: pass
tools/checkpatch.sh -g upstream/master..fix/stm32h7-protected-memory: pass
git diff --check upstream/master..fix/stm32h7-protected-memory: pass
```
## PR verification Self-Check
* [x] This PR introduces only one functional change.
* [x] I have updated all required description fields above.
* [x] My PR adheres to the contributing guidelines and coding standard.
* [ ] My PR is still work in progress.
* [x] My PR is ready for review and can be safely merged.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
