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#![no_std]
#![feature(llvm_asm)]
#![feature(global_asm)]
#![feature(naked_functions)]
use r0;
pub use xtensa_lx106_rt_proc_macros::{entry, pre_init, exception, interrupt};
pub use crate::exception::{ExceptionCause, ExceptionContext};
pub mod exception;
pub mod interrupt;
#[doc(hidden)]
#[no_mangle]
#[link_section = ".iram.text"]
pub unsafe extern "C" fn DefaultPreInit() {}
const CRYSTAL_26MHZ: (u8, u8) = (136, 145);
const CRYSTAL_40MHZ: (u8, u8) = (8, 129);
pub enum CrystalFrequency {
Crystal26MHz,
Crystal40MHz,
}
pub fn set_crystal_frequency(crystal: CrystalFrequency) {
match crystal {
CrystalFrequency::Crystal26MHz => unsafe { configure_pll(CRYSTAL_26MHZ) },
CrystalFrequency::Crystal40MHz => unsafe { configure_pll(CRYSTAL_40MHZ) }
}
}
extern "C" {
fn rom_i2c_writeReg(block: u8, host_id: u8, reg_add: u8, data: u8);
}
unsafe fn configure_pll((reg1, reg2): (u8, u8)) {
rom_i2c_writeReg(103, 4, 1, reg1);
rom_i2c_writeReg(103, 4, 2, reg2);
}
#[doc(hidden)]
#[no_mangle]
pub unsafe extern "C" fn Reset() -> ! {
extern "C" {
static mut _bss_start: u32;
static mut _bss_end: u32;
static mut _data_start: u32;
static mut _data_end: u32;
static _sidata: u32;
static mut _init_start: u32;
}
extern "Rust" {
fn main() -> !;
fn __pre_init();
}
set_crystal_frequency(CrystalFrequency::Crystal26MHz);
__pre_init();
r0::zero_bss(&mut _bss_start, &mut _bss_end);
r0::init_data(&mut _data_start, &mut _data_end, &_sidata);
set_vecbase(&_init_start as *const u32);
main()
}
#[doc(hidden)]
#[inline]
unsafe fn set_vecbase(base: *const u32) {
llvm_asm!("wsr.vecbase $0" ::"r"(base) :: "volatile");
}