peekpoke/
peekpoke.rs

1use std::rc::Rc;
2use std::cell::RefCell;
3use std::num::ParseIntError;
4
5use clap::Parser;
6
7use jtag_taps::cable;
8use jtag_taps::statemachine::JtagSM;
9use jtag_taps::taps::Taps;
10
11use jtag_adi::{ArmDebugInterface, MemAP};
12
13#[derive(Parser, Debug)]
14#[command(author, version, about, long_about = None)]
15struct Args {
16    #[arg(short, long)]
17    cable: String,
18    #[arg(short, long)]
19    baud: u32,
20    #[arg(short, long, default_value_t = 0)]
21    /// Which JTAG TAP to use
22    tap_index: usize,
23    #[arg(short, long, default_value_t = 0)]
24    /// Which access port to use
25    ap_num: u32,
26    addr: String,
27    #[arg(long)]
28    write: Option<String>,
29}
30
31fn parse_int(x: &str) -> Result<u32, ParseIntError> {
32    if x.starts_with("0x") {
33        let len = x.len();
34        u32::from_str_radix(&x[2..len], 16)
35    } else {
36        str::parse(&x)
37    }
38}
39
40fn main() {
41    let args = Args::parse();
42    let cable = cable::new_from_string(&args.cable, args.baud).expect("cable");
43    let jtag = JtagSM::new(cable);
44    let mut taps = Taps::new(jtag);
45    taps.detect();
46
47    // IDCODE instruction
48    let ir = vec![14];
49    taps.select_tap(args.tap_index, &ir);
50    let dr = taps.read_dr(32);
51    let idcode = u32::from_le_bytes(dr.try_into().unwrap());
52
53    // Verify ARM ID code
54    if idcode != 0x4ba00477 {
55        eprintln!("Warning: unexpected idcode {:x}", idcode);
56    }
57
58    let adi = Rc::new(RefCell::new(ArmDebugInterface::new(taps)));
59    let mut mem = MemAP::new(adi.clone(), args.ap_num);
60
61    let addr = parse_int(&args.addr).expect("failed to parse address");
62
63    if let Some(value) = args.write {
64        let value = parse_int(&value).expect("failed to parse value");
65        mem.write(addr, value).expect("write");
66        println!("Success");
67    } else {
68        let val = mem.read(addr).expect("read");
69        println!("0x{:x} = 0x{:x}", addr, val);
70    }
71}
peekpoke/peekpoke.rs

peekpoke/
peekpoke.rs
