HBM

HBM is a hardware buffer allocator.

hbm crate provides a Rust library to allocate, export/import, and access hardware buffers.

hbm-minigbm crate provides an unstable C API for minigbm's internal use.

hbm-gralloc crate will (it is currently empty) provide a HAL service for Graphics Allocator interface and an SP-HAL for Graphics Mapper interface on Android. It is mainly built via the Android build system rather than via cargo.

TODOs

• multi-backend
  • e.g., drm-kms adds alignment and modifier constraints, vulkan decides the layout, dma-heap allocates dma-buf, and vulkan again maps/copies
• more backends, such as vaapi, v4l2, libcamera, etc.
• policy backend
  • collect constraints and generate a policy offline
  • load constraints from the policy at runtime
  • this is useful when sandboxed or for non-queryable constraints
• require modifiers
• no_std
• hbm-gralloc
  • aidl codegen
  • implement allocator and mapper