#![no_std]
#![no_main]
#![feature(asm)]
#![feature(global_asm)]
#![feature(naked_functions)]
#![feature(compiler_builtins_lib)]
#![feature(never_type)]

use core::mem::uninitialized;

use r0::zero_bss;
use compiler_builtins as _;

mod regs;
mod cortex_a9;
mod slcr;
mod uart;
mod stdio;
mod eth;

use crate::regs::{RegisterR, RegisterW};
use crate::cortex_a9::{asm, regs::*, mmu};

extern "C" {
    static mut __bss_start: u32;
    static mut __bss_end: u32;
    static mut __stack_start: u32;
}

#[link_section = ".text.boot"]
#[no_mangle]
#[naked]
pub unsafe extern "C" fn _boot_cores() -> ! {
    const CORE_MASK: u32 = 0x3;

    match MPIDR.read() & CORE_MASK {
        0 => {
            SP.write(&mut __stack_start as *mut _ as u32);
            boot_core0();
        }
        _ => loop {
            // if not core0, infinitely wait for events
            asm::wfe();
        },
    }
}

#[naked]
#[inline(never)]
unsafe fn boot_core0() -> ! {
    l1_cache_init();
    zero_bss(&mut __bss_start, &mut __bss_end);

    let mmu_table = mmu::L1Table::get()
        .setup_flat_layout();
    mmu::with_mmu(mmu_table, || {
        main();
        panic!("return from main");
    });
}

fn l1_cache_init() {
    // Invalidate TLBs
    tlbiall();
    // Invalidate I-Cache
    iciallu();
    // Invalidate Branch Predictor Array
    bpiall();
    // Invalidate D-Cache
    dccisw();
}

fn main() {
    println!("Main.");

    let mut eth = eth::Eth::default([0x0, 0x17, 0xde, 0xea, 0xbe, 0xef]);
    println!("Eth on");
    eth.reset_phy();

    let mut rx_descs: [eth::rx::DescEntry; 8] = unsafe { uninitialized() };
    let mut rx_buffers = [[0u8; 1536]; 8];
    let mut eth = eth.start_rx(&mut rx_descs, &mut rx_buffers);
    let mut tx_descs: [eth::tx::DescEntry; 8] = unsafe { uninitialized() };
    let mut tx_buffers = [[0u8; 1536]; 8];
    let mut eth = eth.start_tx(&mut tx_descs, &mut tx_buffers);

    loop {
        match eth.recv_next() {
            Ok(Some(pkt)) => {
                print!("eth: rx {} bytes", pkt.len());
                for b in pkt.iter() {
                    print!(" {:02X}", b);
                }
                println!("");
            }
            Ok(None) => {}
            Err(e) => {
                println!("eth rx error: {:?}", e);
            }
        }

        match eth.send(512) {
            Some(mut pkt) => {
                let mut x = 0;
                for b in pkt.iter_mut() {
                    *b = x;
                    x += 1;
                }
                println!("eth tx {} bytes", pkt.len());
            }
            None => println!("eth tx shortage"),
        }
    }
    panic!("End");
}

#[panic_handler]
fn panic(info: &core::panic::PanicInfo) -> ! {
    println!("\nPanic: {}", info);

    slcr::RegisterBlock::unlocked(|slcr| slcr.soft_reset());
    loop {}
}

#[no_mangle]
pub unsafe extern "C" fn PrefetchAbort() {
    panic!("PrefetchAbort");
}

#[no_mangle]
pub unsafe extern "C" fn DataAbort() {
    panic!("DataAbort");
}