How to copy OS backup image from SD card
For copy OS image from SD card you will need SD Card Reader and one of following programs:
Hex Workshop or WinHex.
SD dump format
The format of this dump are detailed below.
General format
The general format of a SD card dump is consisting of a header and a ROM image dump:
The ROM image specifications are one of the following.
| Image type |
Command |
Size |
| IPL |
r2sd strap |
3072 bytes (0x00000C00) |
| Bootloader (SPL) |
r2sd boot |
264192 bytes (0x00040800) |
| Bootloader and Windows CE |
r2sd |
32558080 bytes (0x01F0CC00) |
The image is written raw (without file system) to the SD card, starting at SD block number 0.
The header size and format are specific for the bootloader version that is on the device. The following sections detail the the header formats.
Header format for bootloader version V1.05H
The header for bootloader version 1.05H consists of 2kB (0x0800). See the figure below.
- block 0 Identifier, checksum
The identifier block contains the card type identifier. This must be one of:
- HTC$HB25-000 - identifies a bootloader (SPL) image only
- HTC$HB25-111 - identifies a IPL image only
- HTC$HB25-222 - identifies a ???
- HTC$HB25-333 - identifies a bootloader and Windows CE image
- HTC$HB25-444 - identifies a ???
The checksum contains a WORD wide checksum over the ROM image contents. It's a simple addition of all the bytes in there.