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Jun's Loader Binaries

This instruction contains information how to extract binaries from the Jun's loader.

To understand the meaning of these files see the main README for Jun's loader.

Extracting binaries

Assuming you've got the loader its image:

  1. Attach it: losetup -P /dev/loop1 synoboot_103b_ds3617xs.img

  2. Verify it has the expected partitions:

    # fdisk -l /dev/loop1
Disk /dev/loop1: 50 MiB, 52428800 bytes, 102400 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: AFB38D11-BCEA-4409-B348-F4FEEE602114

Device       Start    End Sectors Size Type
/dev/loop1p1  2048  32767   30720  15M EFI System
/dev/loop1p2 32768  94207   61440  30M Linux filesystem
/dev/loop1p3 94208 102366    8159   4M BIOS boot

  3. Get the early kernel ramdisk

    1. mkdir jun-3617xs-p2
    2. mount -o ro /dev/loop1p2 jun-3617xs-p2
    3. mkdir extra_lzma-3617xs
    4. cd extra_lzma-3617xs
    5. xz -dc < ../jun-3617xs-p2/extra.lzma | cpio -idmv

  4. You should now be in a extra_lzma-3617xs folder with a modprobe file:

    # file usr/sbin/modprobe
usr/sbin/modprobe: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, stripped

# du -h usr/sbin/*
36K	usr/sbin/modprobe

# binwalk usr/sbin/modprobe

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             ELF, 64-bit LSB executable, AMD x86-64, version 1 (SYSV)
872           0x368           ELF, 64-bit LSB relocatable, AMD x86-64, version 1 (SYSV)

    This is the file you will find as a binaries/[loader]/modprobe.elf.

  5. To get the kernel module itself you have to strip the first ELF header:
    dd if=usr/sbin/modprobe of=jun.ko bs=1 skip=872
    This is the file you will find as binaries/[loader]/jun.ko

Special thanks