# HiBy R2II Firmware Customizations

This repo contains scripts and files necessary to modify the official HiBy firmware for the R2II. Currently it adds a mechanism to run a shell script off the SD card at bootup. It does this by adding some custom lines to the `/usr/bin/hiby_player.sh` script.

## Pre-Requisites

The system image being modified is a UBIFS image, so you will need the tooling to work with those. Since my host kernel is missing the `ubi` module, I did this in a newly created Arch Linux VM. These are the packages I needed to install with `pacman`:

- `p7zip` (for the `7z` command)
- `mtd-utils` (for `flash_erase` and other MTD commands)
- `cdrkit` (for the `genisoimage` command)

## Building the Custom Firmware

These instructions are based largely on [SuperTaiyaki/hiby-firmware-tools](https://github.com/SuperTaiyaki/hiby-firmware-tools):

1. Unpack the stock firmware and rename the original `SYSTEM.UBI` image:
   ```
   7z x -ooriginal/unpack original/r2ii_1.1b1.upt
   mv original/unpack/SYSTEM.UBI original/unpack/SYSTEM-ORIG.UBI
   ```
2. Mount the renamed `SYSTEM-ORIG.UBI` image. Make sure that no MTD nodes already exist in your system (`ls /dev/mtd*` should return no matches).
   ```
   sudo modprobe nandsim first_id_byte=0x2c second_id_byte=0xda third_id_byte=0x90 fourth_id_byte=0x95
   sudo flash_erase /dev/mtd0 0 0
   sudo ubiformat /dev/mtd0
   sudo modprobe ubi
   sudo ubiattach -m 0
   sudo ubimkvol /dev/ubi0 -a 4096 -N hiby -s 128MiB
   sudo ubiupdatevol /dev/ubi0_0 original/unpack/SYSTEM-ORIG.UBI
   sudo mount /dev/ubi0_0 /mnt
   ```
3. Make a copy of the original firmware file system:
   ```
   sudo cp -R /mnt customized
   ```
4. Replace files in the original firmware copy with the customized versions:
   ```
   sudo cp -R custom-files/* customized/
   ```
5. Repackage the customized firmware into a new `SYSTEM.UBI` image:
   ```
   sudo mkfs.ubifs -x lzo -d customized -e 0x1F000 -c 512 -m 0x800 -o original/unpack/SYSTEM.UBI
   ```
6. Update the md5 hash in `UPDATE.TXT` to match the new `SYSTEM.UBI` image:
   ```
   sed -i '7,$s/md5=.*/md5='"$(md5sum original/unpack/SYSTEM.UBI | cut -d\  -f1)/" original/unpack/UPDATE.TXT
   ```
7. Generate the new firmware update file:
   ```
   genisoimage -l -o r2ii.upt original/unpack/{SYSTEM.UBI,UBOOT.BIN,UIMAGE.BIN,UPDATE.TXT,VERSION.TXT,_GITIGNO}
   ```

Now you can copy the `r2ii.upt` file that was generated to the root of your R2II's SD card, then initiate a firmware update through the `System->Firmware update->Via SD-card` menu. If you are unable to get into the System menu, you can also force an update by turning the device off, then holding the Power and FFWD buttons together until the Hiby logo appears.

## Using the Custom Firmware

If you place a text file named `startup.sh` onto the root of your SD card, that script will be executed every time the device boots up just prior to the HiBy player interface being launched.