About Flash Recovery and Flash Doctor
Performing Flash Recovery with Flash Doctor: What is the Success Rate?
Before we answer this question, we should first discuss the following topic: The differences between data recovery from hard disk drive and flash storage device.
Data recovery is the whole process, which rebuilds the inaccessible/lost/corrupted data due to hardware fault/damage, misoperations and so on, back to be original readable data.
A very important knowledge we need to know, before we talk about physical-level data recovery, is “What is Firmware?”
Firmware is a term sometimes used to denote the fixed, usually rather small, programs that internally control various electronic devices. Typical examples range from end-user products such as remote controls or calculators, through computer parts and devices like hard disks, keyboards, TFT screens or memory cards, all the way to scientific instrumentation and industrial robotics. Also more complex consumer devices, such as mobile phones, digital cameras, synthesizers, etc., contain firmware to enable the device's basic operation as well as implementing higher level functions.
Naturally, there are no strict, or well defined, boundaries between firmware and software, both are quite loose descriptive terms. However, firmware is typically involved with very basic low-level operations in a device, without which the device would be completely non-functional. Firmware is also a relative term, as most embedded devices contain firmware at more than one level. Subsystems such as LCD modules, flash chips, communication controllers etc, have their own (usually fixed) program code and/or microcode, regarded as 'part of the hardware' by the higher level firmware.
Simple firmware typically resides in ROM or OTP/PROM, while more complex firmware often employs flash memory to allow for updates. Common reasons for updating firmware include fixing bugs or adding features to the device. Doing so usually involves loading a binary image file provided by the manufacturer into the device, according to a specific procedure; this is sometimes intended to be done by the end user.
Institute of Electrical and Electronics Engineers (IEEE) Standard Glossary of Software Engineering Terminology, Std 610.12-1990, defines firmware as follows:
"The combination of a hardware device and computer instructions and data that reside as read-only software on that device.”
So we know the firmware is critical for an electronic storage device to work properly since it is the firmware that controls the electronic devices to work as they were designed to; and just because of that, the firmware, being used so frequently, is very easy to be damaged even during the normal usage, and firmware problem has been one of the major reasons of data lost due to physical damage.
The first difference: the symptoms of hard disk drive and flash storage device in case of a firmware corruption:
Firmware corruption symptoms of hard disk drive:
1. Drive spins and seeks normally, without clicking noise, but it can’t be detected correctly (model number, capacity…) when being diagnosed.
2. The drive is detected as its factory alias (such as Athena, N40P for Maxtor).
3. For certain drives (for example, some drives manufactured by Maxtor), the drive is working in manufacturer mode (no data can be read from/written to the drive).
But for flash storage device, in case of a firmware corruption, it has the following symptoms:
1. The correct model number can be detected, but the capacity detected becomes very small (usually falsely detected as 8.4 MB or 16 MB).
2. Device detected as general manufacturer model.
3. Correct device model number and capacity can be detected, but all the blocks are defective and inaccessible.
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