Struct BackBuffer 

pub struct BackBuffer<'a> { /* private fields */ }

Mutable view of a framebuffer the renderer currently owns.

CPU writes happen through BackBuffer::cpu_slice. DMA submissions go through BackBuffer::dma_dst, which reborrows the buffer and locks out CPU access for the duration of the transfer.

Implementations

impl<'a> BackBuffer<'a>

pub fn wrap(fb: &'a mut FrameBuffer) -> Self

Wrap a mutable reference to a FrameBuffer.

pub fn framebuffer(&self) -> &FrameBuffer

Underlying FrameBuffer.

pub fn framebuffer_mut(&mut self) -> &mut FrameBuffer

Underlying FrameBuffer (mutable metadata, not pixels).

pub fn addr(&self) -> PhysAddr

Physical base address.

pub fn dma_addr(&self) -> DmaAddr

DMA bus address (for writing into DMA2D OMAR).

pub fn width(&self) -> u32

Width in pixels.

pub fn height(&self) -> u32

Height in pixels.

pub fn stride_bytes(&self) -> u32

Row stride in bytes.

pub fn format(&self) -> PixelFmt

Pixel format.

pub fn dma_dst<'b>(&'b mut self) -> BorrowedForDma<'b, BackBuffer<'a>>

Produce a reborrow suitable for DMA-engine submission.

The returned BorrowedForDma carries a mutable reborrow of this back buffer for lifetime 'b. While it — or any InFlight derived from it — is alive, self is borrowed and CPU access via BackBuffer::cpu_slice is rejected by the borrow checker.

pub unsafe fn cpu_slice(&mut self) -> &mut [u8]

CPU byte access to the back buffer’s RAM.

Safety

The caller must ensure:

• no DMA master is currently reading or writing the buffer (the InFlight lifecycle already encodes this for DMA2D paths),
• the RAM region is actually mapped and writable (established by FrameBuffer::from_phys),
• no other &mut [u8] or &[u8] referencing overlapping bytes is alive for the returned slice’s lifetime.