Function spectrusty_formats::sna::load_sna48

pub fn load_sna48<R: Read, S: SnapshotLoader>(
    rd: R,
    loader: &mut S
) -> Result<()>

Loads a 48k SNA file from rd into the provided snapshot loader implementing SnapshotLoader.

Note

This function handles only the 48k SNA files.

Errors

This function will return an error if the file is too small or the SP register points into the ROM page. Other errors may also be returned from attempts to read the file.

Examples found in repository

src/sna.rs (line 185)

pub fn load_sna<R: Read + Seek, S: SnapshotLoader>(
        mut rd: R,
        loader: &mut S
    ) -> Result<()>
{
    let cur_pos = rd.seek(SeekFrom::Current(0))?;
    let end_pos = rd.seek(SeekFrom::Current(SNA_LENGTH as i64))?;
    if end_pos - cur_pos != SNA_LENGTH {
        return Err(Error::new(ErrorKind::InvalidData, "SNA: wrong size of the supplied stream"));
    }

    let mut sna_ext = SnaHeader128::default();
    let ext_read = sna_ext.read_struct_or_nothing(rd.by_ref())?;

    rd.seek(SeekFrom::Start(cur_pos))?;

    if !ext_read {
        return load_sna48(rd, loader)
    }

    let mut cpu = Z80NMOS::default();
    let border = read_header(rd.by_ref(), &mut cpu)?;
    cpu.set_pc(u16::from_le_bytes(sna_ext.pc));

    let extensions = if sna_ext.trdos_rom != 0 {
        Extensions::TR_DOS
    }
    else {
        Extensions::NONE
    };
    let model = ComputerModel::Spectrum128;
    loader.select_model(model, extensions, border, ReadEarMode::Issue3)
          .map_err(|e| Error::new(ErrorKind::Other, e))?;

    let index48 = [5, 2];
    let last_page = Ula128MemFlags::from_bits_truncate(sna_ext.port_data)
                    .last_ram_page_bank();
    for page in index48.iter().chain(
                    Some(&last_page).filter(|n| !index48.contains(n))
                ) {
        loader.read_into_memory(
            MemoryRange::Ram(page * PAGE_SIZE..(page + 1) * PAGE_SIZE), rd.by_ref()
        )?;
    }

    rd.seek(SeekFrom::Current(size_of::<SnaHeader128>() as i64))?;

    for page in (0..8).filter(|n| !index48.contains(n) && *n != last_page) {
        loader.read_into_memory(
            MemoryRange::Ram(page * PAGE_SIZE..(page + 1) * PAGE_SIZE), rd.by_ref()
        )?;
    }
    loader.assign_cpu(CpuModel::NMOS(cpu));
    loader.write_port(0x7ffd, sna_ext.port_data);
    if sna_ext.trdos_rom == 1 {
        loader.tr_dos_rom_paged_in();
    }
    Ok(())
}