325     fn test_device(flash: &mut dyn Flash, erased_val: u8) {  in test_device()
326         let sectors: Vec<Sector> = flash.sector_iter().collect();  in test_device()
328         flash.erase(0, sectors[0].size).unwrap();  in test_device()
329         let flash_size = flash.device_size();  in test_device()
330         flash.erase(0, flash_size).unwrap();  in test_device()
331         assert!(flash.erase(0, sectors[0].size - 1).is_bounds());  in test_device()
334         flash.write(0, &[0x55]).unwrap();  in test_device()
336         flash.read(0, &mut buf).unwrap();  in test_device()
339         flash.erase(0, sectors[0].size).unwrap();  in test_device()
340         flash.read(0, &mut buf).unwrap();  in test_device()
347             flash.write(sector.base, &byte).unwrap();  in test_device()
348             flash.write(sector.base + sector.size - 1, &byte).unwrap();  in test_device()
356             flash.read(sector.base, &mut buf).unwrap();  in test_device()