ableos/ableos/src/devices/pci/piix.rs

81 lines
2.1 KiB
Rust

// FIXME: platform agnostic paging stuff
use x86_64::structures::paging::{PhysFrame, FrameAllocator, Size4KiB, mapper::MapToError, Mapper, Page};
use x86_64::VirtAddr;
use super::{PciDeviceInfo, check_device};
const PRDT_START: u64 = 0x_ffff_ffff_0000_0000;
pub struct Piix {
device_info: PciDeviceInfo,
prdt_frame: Option<PhysFrame>,
}
impl Piix {
pub fn new(bus: u8, device: u8) -> Option<Self> {
let device_info = check_device(bus, device)?;
trace!("device_info: {device_info}");
Some(Self {
device_info,
prdt_frame: None,
})
}
pub fn allocate_dma_frame(
&mut self,
mapper: &mut impl Mapper<Size4KiB>,
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
) -> Result<(), MapToError<Size4KiB>> {
use x86_64::structures::paging::PageTableFlags as Flags;
let prdt_frame = frame_allocator.allocate_frame()
.ok_or(MapToError::FrameAllocationFailed)?;
let flags = Flags::NO_CACHE | Flags::PRESENT | Flags::WRITABLE;
unsafe {
mapper.map_to(
Page::containing_address(VirtAddr::new(PRDT_START)),
prdt_frame,
flags,
frame_allocator,
)?.flush()
}
trace!("{prdt_frame:#?}");
self.prdt_frame = Some(prdt_frame);
Ok(())
}
pub fn read(&self) {
// bus master interface base address
let bmiba = self.device_info.bars[4] as *mut BusMasterInterface;
// bmiba.bmidtpp = prdt;
}
}
#[derive(Copy, Clone, Debug)]
#[repr(C, packed)]
struct BusMasterInterface {
/// Bus Master IDE Command (primary)
pub bmicp: u8,
/// Reserved
pub _0: u8,
/// Bus Master IDE Status (primary)
pub bmisp: u8,
/// Reserved
pub _1: u8,
/// Bus Master IDE Descriptor Table Pointer (primary)
pub bmidtpp: u32,
/// Bus Master IDE Command (secondary)
pub bmics: u8,
/// Reserved
pub _2: u8,
/// Bus Master IDE Status (secondary)
pub bmiss: u8,
/// Reserved
pub _3: u8,
/// Bus Master IDE Descriptor Table Pointer (secondary)
pub bmidtps: u32,
}