Firmware Repair of HDD & Data Recovery Technology
1. Summary:
     Data recovery techniques can generally be divided into three levels: logical level, firmware level and physical layer. Logic level focuses on the data recovery in file system level. There are already many tools of this kind. The connection of firmware level and the physical level is generally close. It is data recovery work conducted when the physical structure of storage device is damaged. For example, the HDD was  damaged from being hit. Usually, the firmware fault of HDD looks much alike hardware fault, so firmware damaged is often taken as hardware fault. Additionally, when the hardware of HDD gets damaged, the firmware is very likely to be damaged, too. That is double faults of firmware and hardware. So data recovery technology of firmware level and physical level are related tightly.
     There are many data recovery tools in logical level in China and abroad. They have a common characteristic. That is the HDD must be able to be recognized so that the tool can work properly. Otherwise all the software that works in logical level will be useless because they work on the disk drive of operating system, and they rely on the operating system to manage and access the disk. In terms of operating system, the hard disk provides a flat storage space, with file system driver is attached onto it, and plan their allocation of file storage in this flat storage space. If the hard disk fails with sectors cannot be accessed, then all work in logical level is futile. In this case, you need to perform firmware upgrade and other repair of hard drive. Just the opposite, there are few tools that can process HDD in firmware level. Processing firmware of HDD requires specially developed HDD repair card and multiple core technologies of HDD makers. To develop data recovery tool in firmware level, you have to overcome the difficulties of design and development of hardware, scarce related materials and technology monopoly of foreign HDD makers etc.

2. The necessity of firmware-level data recovery tools:
     From above mentioned three levels of data recovery technology, you can see that firmware-level data recovery is part of the underlying data recovery technology. It can serve as an important part in the data recovery and forensics and play a key role in some scenes. Typically, you need to process HDD in firmware level in the following cases:
(1). A lot of bad sectors appear in hard disk (physical or logical). Usually when there are a lot of bad sectors in the hard disk, common software (such as WinHex) cannot handle with it properly, and can easily cause stuck and other issues. At this time, you can use a specialized firmware-level data recovery tools for comprehensive hard disk mirroring. Professional tools have a variety of policy setting and factory reading schemes. You can maximize the extraction of data from the hard disk with bad sectors.

(2). Firmware damage of hard drive. When firmware corruption of HDD appears, in most cases the hard disk cannot work. At this time, the operating system cannot recognize the hard drive, or there can be all bad sectors or other issues. As HDD makers abide by general rules of software development when designing HDDs, the more complicated HDD is, the more difficult it is to develop firmware. So design errors(BUG) may occur at some rate. In the same way, being a software program, firmware is not able to avoid such things. For instance, there was a influential “firmware” incident of Seagate at the end of 2008. Since there was design error in Seagate SD15 firmware, many users came across situations that they could not boot, got stuck sometimes and non-identification of HDD etc. As the impact scope of that incident was wide, people start to pay more attention to data security. Not only Seagate, actually HDD of all brands can have firmware damaged problem in certain service conditions. It may be caused by design errors, poor service condition, hardware faults or artificial destruction of data recovery company etc. In this case, if you want to recover the data of HDD, you need to repair the firmware.
3. Physically damaged HDD usually require firmware processing and repairing. This is mainly for two reasons: First, physical damage will usually result in damage to the firmware. So after hardware repair, you should also repair the firmware. Second, you need to process the firmware after physical repair of hardware. For example, if the HDD head crashed, the usual approach is to find a HDD of the same type and replace its head to the failed HDD. However, as there are slight differences between adaptation parameters head, you may need to re-adjust configured head parameter information of firmware after replacing the head, so as to make the new head work. Such operations require processing firmware. Thus it can be seen that firmware processin