Function write_config 

pub fn write_config(
    ctx: &Ctx,
    config: &str,
    commit: bool,
    backup: &str,
    base_image: Option<&str>,
    index: u16,
    wait: u64,
    p: &mut dyn Progress,
) -> Result<()>

Install a .rcvbp into the card’s parameter flash.

The erase covers the whole 64KB block, so the block is read first, only the parameter region is replaced, and everything else is written back byte for byte. A backup of the original block is always saved before any write.