# UniFlash: an opensource Unisoc/Spreadtrum feature phone flash reader/writer

## About

Cross-platform MediaTek feature phone dumping had been achieved long ago with [MTreader](https://gitlab.com/suborg/mtreader). Now it's time to do the same for Unisoc (ex-Spreadtrum) phones. And not only that, but also to be able to flash them!

Unfortunately, the architecture of Unisoc chipset boot ROM doesn't allow us to get away without any loader blobs. So, some FDL binaries are also shipped in this repo.

UniFlash started out as UniDump (see [this blog post](https://chronovir.us/2021/12/18/Opus-Spreadtrum/)) but had been quickly upgraded to do both tasks.

The `uniflash.py` file is the main script to use. The `unicmd.py` file is the library created for easier command interface encapsulation.

For further dumped firmware unpacking/repacking, I recommend [bzpwork](https://github.com/ilyazx/bzpwork) by ilyazx.

**Note: the flasher part is still under testing/study, use at your own risk!**

## Dependencies

Python 3.8+ and PyUSB.

## Usage

Run `python uniflash.py -h` to see all parameters. But there are several typical scenarios that UniFlash officially supports.

**Note**: you need to hold a bootkey pressed when connecting the device for it to be detected correctly. This key can vary across devices. Typically it's Call, Soft Left, Soft Right, Center, 9 or #, but it can be anything else.

Some chipset versions (esp. the ones before SC6531E) require the following procedure to connect in order to initiate successful data transfer:

1. Pull out the battery and the cable.
2. Insert the cable.
3. Hold the bootkey and then insert the battery.

UniFlash ships with several typical targets that you can specify with `-t` (`--target`) parameter and not have to configure anything else:

- `sc6531efm_generic` (default) - for SC6531E/F/M with no signed FDLs;
- `sc6530_generic` - for SC6530 and SC6531B/C/DA with no signed FDLs;
- `sc7703a_generic` - for SC7703A with no signed FDLs.

If you want to, the targets are fully overridable with individual parameters, see program help for all details.

### SC6531E

This is the default target for UniFlash, FDLs for it are shipped in the repo and you don't need to configure anything else (even `-t` parameter) unless your model requires signed FDLs.

For SC6531E, firmware is usually 4MB long, so you just need to run `python uniflash.py dump your-output-file.bin` to dump the firmware image and `python uniflash.py flash your-input-file.bin` to flash it.

### SC6531F/M

For SC6531F or SC6531M, the target is still `sc6531efm_generic` unless your model uses signed FDLs. However, **specifying the wrong dump length and attempts to write flash from the same dump can make the device unbootable!**

Here, firmware can be larger, so you need to pass in the length. As with any integer parameter here, you can pass it in hexadecimal format as well.

E.g. for CAT B26 (bootkey is `#`) the dumping command is: `python uniflash.py -l 0x800000 dump b26.bin`

### SC6531C

SC6531C is a single-FDL variant. Here, if your model doesn't require signed FDLs, you need to specify `sc6530_generic` target and typically 8MB length, for instance, for Alcatel OT-2051D the boot key is Call key and the command to dump is: `python uniflash.py -t sc6530_generic -l 0x800000 dump ot2051d.bin`

**Note**: for SC6531C, only readback is supported as of now.

### SC6531D and lower

For now, SC6531DA and other variants of SC6531 chipset older than SC6531CA are not supported.

### Add your own targets

If you work with non-standard devices but don't find specifying individual FDL parameters every time convenient, you can always create your own target and refer to it via the `-t` parameter. It's pretty straightforward: you just need to collect FDL loader files for your device, rename them accordingly and place them into `fdls/` directory in the root of UniFlash project.

For two-FDL targets (more common scenario), the naming scheme is like this: `[targetname]_[load_addr_1]_fdl1.bin` and `[targetname]_[load_addr_2]_fdl2.bin`.

For single-FDL targets, the FDL file name must be `[targetname]_[load_addr]_single.bin`.

For example, if you have found signed FDL loaders for Nokia 105 2019 somewhere and want to add this phone as a target, you know that they are loaded into `0x40004000` and `0x14000000` respectively, so you can rename them, for instance, to `sc6531efm_nokia_0x40004000_fdl1.bin` and `sc6531efm_nokia_0x14000000_fdl2.bin`, place them into `fdls/` and then just use `-t sc6531efm_nokia` in your commands.

## Credits

Created by Luxferre in 2021. All files except the FDL blobs are public domain.