os-z80/initrd_maker.rs

47 lines
1.9 KiB
Rust
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2023-01-29 11:03:53 -06:00
use std::{
env::args,
fs::File,
io::{self, Write},
path::Path,
};
const BLOCK_SIZE: u16 = 256;
fn main() {
let mut archive = File::create("initrd").expect("Could not open initrd");
for file_path in args().skip(1) {
let file_path = Path::new(&file_path);
let file_name = file_path.file_name().unwrap();
let file_name_len =
u8::try_from(file_name.len()).expect("File name length greater than 256 bytes");
if file_name_len > 252 {
panic!("File {:?} has name longer than 252 bytes", file_name);
}
let mut file = File::open(file_path).expect("File did not exist");
let length = u16::try_from(file.metadata().expect("Could not get file metadata").len())
.expect("File size greater than 64 KiB");
let file_num_blocks = (length / BLOCK_SIZE) + if length % BLOCK_SIZE != 0 { 1 } else { 0 };
let mut header_block = Vec::new();
header_block.push(file_name_len);
header_block.extend_from_slice(file_name.to_str().unwrap().as_bytes());
header_block.push(0);
header_block.extend_from_slice(&length.to_le_bytes());
header_block.extend_from_slice(&file_num_blocks.to_le_bytes());
header_block.resize(BLOCK_SIZE as usize, 0);
archive
.write_all(&header_block)
.expect("Could not write to initrd");
let bytes_written =
io::copy(&mut file, &mut archive).expect("Could not read from file/write to initrd");
if (bytes_written as u16 % BLOCK_SIZE) != 0 {
let bytes_padding = (BLOCK_SIZE) - (bytes_written as u16 % BLOCK_SIZE);
for _ in 0..bytes_padding {
archive.write_all(&[0]).expect("Could not write to initrd");
}
}
}
archive
.write_all(&[0; 256])
.expect("Could not write to initrd");
}