zfi 0.2.0

Zero-cost and safe interface to UEFI firmware
Documentation 
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#![no_std]

pub use self::allocator::*;
pub use self::boot::*;
pub use self::console::*;
pub use self::debug::*;
pub use self::device::*;
pub use self::filesystem::*;
pub use self::guid::*;
pub use self::header::*;
pub use self::image::*;
pub use self::memory::*;
pub use self::path::*;
pub use self::pointer::*;
pub use self::proto::*;
pub use self::runtime::*;
pub use self::status::*;
pub use self::string::*;
pub use self::system::*;
pub use self::time::*;
pub use zfi_macros::*;

use alloc::boxed::Box;
use core::cell::RefCell;
use core::fmt::Write;
use core::ptr::null;

mod allocator;
mod boot;
mod console;
mod debug;
mod device;
mod event;
mod filesystem;
mod guid;
mod header;
mod image;
mod memory;
mod path;
mod pointer;
mod proto;
mod runtime;
mod status;
mod string;
mod system;
mod time;

extern crate alloc;
extern crate self as zfi;

static mut ST: *const SystemTable = null(); // We can't panic without this so Option useless here.
static mut IMAGE: *const Image = null(); // Same here.
static mut DEBUG_WRITER: Option<RefCell<Box<dyn Write>>> = None;

/// Initializes the ZFI.
///
/// This must be called before using any ZFI API. Usually you should call this right away as the
/// first thing in the `efi_main`. See project README for an example.
///
/// The function passed via `debug_writer` can use any ZFI API.
///
/// # Safety
/// Calling this function more than once is undefined behavior.
pub unsafe fn init(
    im: &'static Image,
    st: &'static SystemTable,
    debug_writer: Option<fn() -> Box<dyn Write>>,
) {
    // Initialize foundation.
    ST = st;
    IMAGE = im;

    // Check EFI version.
    if st.hdr().revision() < TableRevision::new(1, 1) {
        panic!(
            "UEFI version is too old to run {}",
            im.proto().file_path().display()
        );
    }

    // Initialize debug log.
    if let Some(f) = debug_writer {
        DEBUG_WRITER = Some(RefCell::new(f()));
    }
}

/// Returns `im` that was passed to [`init()`].
pub fn current_image() -> &'static Image {
    // SAFETY: This is safe because the only place that write IMAGE is our init function.
    unsafe { &*IMAGE }
}

/// Returns `st` that was passed to [`init()`].
pub fn system_table() -> &'static SystemTable {
    // SAFETY: This is safe because the only place that write ST is our init function.
    unsafe { &*ST }
}