How Synology Assistant works with the stage of kernel running by packing installation mode of 3rd Menu

[caryyu]

Here's a question that i'm curious about how Synology Assistant can be able to automatically detect the host and install rest of OS parts remotely. as i know like Ubuntu, All parts of installation files (sys-linux boot loader and kernel zImage and system files) must be in the same flask disk or cd/rom; how come this can be separated to different ways. 

[sbv3000]

As far as I know, Real Synology boxes have a small boot loader disk on module or boot rom flash which provides the minimum boot requirements (disk/network drivers, dhcp etc) once these are loaded the rest of the boot process and o/s are handled by Disk Station Manager (DSM) which is installed on a system partition on all disks. The XPE boot loader replaces the synology dom.

When you install for the first time, the dom/boot loader provides the minimal setup that allows Assistant to find the box and install DSM, after that, its as above.

[caryyu]

12 hours ago, sbv3000 said:

As far as I know, Real Synology boxes have a small boot loader disk on module or boot rom flash which provides the minimum boot requirements (disk/network drivers, dhcp etc) once these are loaded the rest of the boot process and o/s are handled by Disk Station Manager (DSM) which is installed on a system partition on all disks. The XPE boot loader replaces the synology dom.

When you install for the first time, the dom/boot loader provides the minimal setup that allows Assistant to find the box and install DSM, after that, its as above.

Which means zImage, the kernel actually is customized right? Because I write the boot loader img to my flash disk and I just only see syslinux boot files and zImage so that i guess zImage is customized which is not pure kernel file. 

[sbv3000]

I'm not a Linux expert to say for sure, but I think your understanding is correct in that the zimage on the xpe boot loader is customised (thats how Jun got it to work with DSM/Synology) but all it does is to emulate the synology boot loader. Dont 'over think' this, it works !

[caryyu]

1 hour ago, sbv3000 said:

I'm not a Linux expert to say for sure, but I think your understanding is correct in that the zimage on the xpe boot loader is customised (thats how Jun got it to work with DSM/Synology) but all it does is to emulate the synology boot loader. Dont 'over think' this, it works !

Today i spent hours to search the kernel resources I think I've already got it; bzImage includes two parts, one is initrd/initramfs, another is kernel, they're all in one file. The key is initrd, this is the one customised,  Next question is that how to get the initrd source code and how to change,then recompile,  I think I need to read more books about Linux kernel knowledges. Cheers. 😄

[IG-88]

hi,

 

(afaik) in jun's loader is still the original bzimage and the trick to overcome the protection sysnology put in place is to insert additional kernel modules into the already running base system when booting

the source and toolchain can be downloaded here

https://sourceforge.net/projects/dsgpl/files/Synology NAS GPL Source/

 

i think if build you own kernel from source it will not work as it will trigger the protection sysnology builds into dsm, the loader mechanism jun uses is kind of stealthy to keep thinks look like the original state

 

[caryyu]

On 10/21/2017 at 5:22 AM, IG-88 said:

hi,

 

(afaik) in jun's loader is still the original bzimage and the trick to overcome the protection sysnology put in place is to insert additional kernel modules into the already running base system when booting

the source and toolchain can be downloaded here

https://sourceforge.net/projects/dsgpl/files/Synology NAS GPL Source/

 

i think if build you own kernel from source it will not work as it will trigger the protection sysnology builds into dsm, the loader mechanism jun uses is kind of stealthy to keep thinks look like the original state

 

How protection Synology builds  works, which stage will trigger this secure checking? you mean on Upstart processing ?  if it does, The ideal way i think is to replace limited modules on Upstart stage and keep original compatible modules with no limitation, but it definitely is a huge project to be done.

Edited October 23, 2017 by caryyu

[IG-88]

you might ask jun what he can say about the protection, and as we are on it, the new 6.2 beta seems to use signed drivers/kernel modules, i guess a new layer to make it harder to use dsm on other hardware

at some point it might not be worth trying to break into dsm, there are other solutions like open media vault (plugins + docker) where the invested time realy contibtes to opensource