//! pci — list PCI devices via the exports table.

#![no_std]
#![no_main]

#[panic_handler]
fn panic(_info: &core::panic::PanicInfo) -> ! {
    loop { core::hint::spin_loop(); }
}

fn put(exports: &rsapi::Exports, buf: &[u8]) {
    (exports.put_line)(rsapi::Line { ptr: buf.as_ptr(), len: buf.len() });
}

fn hex2(b: u8, out: &mut [u8]) {
    let hi = b >> 4; let lo = b & 0xf;
    out[0] = if hi < 10 { b'0' + hi } else { b'a' + hi - 10 };
    out[1] = if lo < 10 { b'0' + lo } else { b'a' + lo - 10 };
}

#[unsafe(no_mangle)]
pub extern "C" fn efi_main(exports: &'static rsapi::Exports, _argc: usize, _argv: *const rsapi::Arg) -> i32 {
    let count = (exports.pci_probe)();
    let mut i = 0u32;
    while i < count {
        let mut d = rsapi::PciDevice { bus: 0, device: 0, function: 0, class: 0, subclass: 0, vendor: 0, device_id: 0 };
        if (exports.pci_device)(i, &mut d) {
            // "XX:XX.F class=XX:XX ven=XXXX dev=XXXX" = 42 bytes max
            let mut buf = [0u8; 42];
            hex2(d.bus, &mut buf[0..2]); buf[2] = b':';
            hex2(d.device, &mut buf[3..5]); buf[5] = b'.';
            buf[6] = b'0' + d.function;
            let class_lbl = b" class=";
            buf[7..7+class_lbl.len()].copy_from_slice(class_lbl);
            let o = 7 + class_lbl.len();
            hex2(d.class, &mut buf[o..o+2]); buf[o+2] = b':';
            hex2(d.subclass, &mut buf[o+3..o+5]);
            let ven_lbl = b" ven=";
            buf[o+5..o+5+ven_lbl.len()].copy_from_slice(ven_lbl);
            let v = o + 5 + ven_lbl.len();
            hex2((d.vendor >> 8) as u8, &mut buf[v..v+2]);
            hex2((d.vendor & 0xff) as u8, &mut buf[v+2..v+4]);
            let dev_lbl = b" dev=";
            buf[v+4..v+4+dev_lbl.len()].copy_from_slice(dev_lbl);
            let dd = v + 4 + dev_lbl.len();
            hex2((d.device_id >> 8) as u8, &mut buf[dd..dd+2]);
            hex2((d.device_id & 0xff) as u8, &mut buf[dd+2..dd+4]);
            put(exports, &buf[..dd+4]);
        }
        i += 1;
    }
    0
}