blob: faadb133a15b55dbb89b21a063407b3387568f30 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
use std;
use rustv::isa;
use rustv::memory::SharedMemory;
use rustv::register_file::RegisterFile;
use rustv::syscall;
use rustv::trap::Trap;
pub struct SyscallHandler<'a> {
memory: SharedMemory<'a>,
}
impl<'a> SyscallHandler<'a> {
pub fn new(memory: SharedMemory<'a>) -> SyscallHandler<'a> {
SyscallHandler {
memory: memory
}
}
}
impl<'a> SyscallHandler<'a> {
fn print(&mut self, registers: &mut RegisterFile) -> Option<Trap> {
let mut base = registers.read_word(isa::Register::X11);
let mut string = vec![];
loop {
let c = self.memory.borrow_mut().read_byte(base);
if let Ok(0x00) = c {
break;
}
else if let Ok(c) = c {
string.push(c);
}
base += 1;
}
let result = std::str::from_utf8(&string);
if let Ok(string) = result {
println!("{}", string);
}
else {
println!("Error printing string: not valid UTF-8: {:?}", result);
}
None
}
}
impl<'a> syscall::SyscallHandler for SyscallHandler<'a> {
// TODO: is trap really appropriate here?
fn syscall(&mut self, registers: &mut RegisterFile) -> Option<Trap> {
let syscall_number = registers.read_word(isa::Register::X10);
match syscall_number {
22 => {
self.print(registers)
}
_ => {
// TODO: some sort of error reporting
None
}
}
}
}
|