Approved version. Approved on: 17:23, 11 January 2021
- Last edited 2 years ago ago
1 Article purpose
The Reserved-memory mechanism allows reserving memory regions in the kernel. This mechanism is used by drivers to allocate buffers in specific memory regions (such as MCU SRAM) or to get a dedicated memory pool that will not be managed by Linux® conventionnal memory allocator (in DDR).
2 Use cases
In STM32 MPU Linux OS, the reserved-memory is used by:
- the dmaengine driver to reserve the region where DMA buffers are allocated, typically MCU SRAM.
- the remoteproc driver to reserve the regions in RETRAM and MCU SRAM where the coprocessor firmware will be loaded.
- the RPMsg driver to reserve the region where RPMsg buffers used for interprocess communication with the coprocessor, are allocated, typically MCU SRAM.
- the Vivante Gcnano driver to reserve the region where the GPU working memory is allocated, typically the DDR.