Method write_word

crates/virtual-machine/src/devices/framebuffer.rs:112–132

(&mut self, addr: u64, data: u32)

        if !self.double_buffered {
            self.version += 1;
        }
    }

    // Publish the back buffer to the front (no-op when single-buffered).
    fn present(&mut self) {
        if self.double_buffered {
            self.front.copy_from_slice(&self.back);
            self.version += 1;
        }
    }
}

impl MemoryAccess for Framebuffer {
    fn read_byte(&mut self, addr: u64) -> Result<u8, VmError> {
        let a = addr as usize;
        if a < FB_BYTES {
            // Reads see the buffer the guest is actively drawing into.
            Ok(self.draw_buffer()[a])
        } else if a < FB_TOTAL_BYTES {
            // Control registers read back as zero.
            Ok(0)
        } else {
            Err(VmError::BusError(addr))
        }