Reserved memory

1 Article purpose[edit]

The Reserved-memory mechanism[1] allows reserving memory regions in the kernel. This mechanism is used by drivers to allocate buffers in specific memory regions (such as internal SRAM[2][3]) or to get a dedicated memory pool that will not be managed by Linux® conventionnal memory allocator (in DDR).

2 Use cases[edit]

In OpenSTLinux, the reserved-memory is used:

  • On STM32MP1 Series by:
  • On STM32MP15x lines More info.png by:
  • 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.

3 References[edit]