Trying out Replicant... (dual boot, revert to CM or to Android?)

Added by Alexander Ofen about 6 years ago

Dear Community,

As I read from the posts about installing, it seems that one flashes the bootloader and copies files to microsds mainly, correct?
is there a way to (by having multiple SD-cards and reflashing each time) to use a mobile phone with Replicant & with CM & Android.

I mean that in the way many people still have a (fall-back, rarely used) windows partitions on their PC they dual boot into occasionally
My question hence is if something similar is possible with Replicant (and i.e. Galaxy S3).
I would enjoy having a chance to "risk-free"/"risk-reduced" tryout Replicant, but be able to i.e. (for later resale etc) to revert to
an Android, or CM.

I have not yet found some info about how and if it is possible to "go back" to a Android or CM.
This info would certainly easy the mind to people interested into Replicant, but not 100% sure if (living with the reduced hardware-support etc)
is accaptable.

Another reason to desire dual boot would be to use a classical (shit proprietary Android) for testing self-developed Apps since... lets
face it most Apps are marketed for the "more ignorant mass of unaware Android users".

Background: I am excited about Replicant and free software. I have no Smartphone, because they have been to proprietary to me

Thank you for the information

Replies (3)

RE: Trying out Replicant... (dual boot, revert to CM or to Android?) - Added by Paul Kocialkowski about 6 years ago

There is a backup/restore functionality of ClockworkMod's recovery (the one we ship among our images) which permits to backup the current system and restore it to its previous state later. That way, you can decide to backup stock Android, install Replicant and backup stock Android if you don't like Replicant. Beware though, if your device doesn't have a recovery partition, you'll have to run recovery by installing it to the kernel partition, which will override the stock kernel (hence, backup will backup the recovery image as kernel, not the stock kernel).

In any way, you can always install CyanogenMod if you don't like Replicant: I'm sure you'll like it better than stock anyway, and it is fully-featured.

As for dual-boot, there are ways to do it. Back in time, we used to dual-boot GNU/Linux and Replicant by filling the recovery partition with the GNU/Linux kernel which would then mount its rootfs from the sdcard. But there is no easy way to do it for Android, you'd at least need to rebuild things to get the mountpoints right.

RE: Trying out Replicant... (dual boot, revert to CM or to Android?) - Added by Alexander Ofen about 6 years ago

Thank you very much for the answer!
Ans Yipiehhh, this is also great news, because it would not force a decisions and as I assume it will eventually go as did
Rockbox (some better firmware/OS for mp3 player) on my Mp3-player... The better system won and I would extremly like
Replicant to win on my Smartphone.

I have to admit (and it is plainly visible) that I am not very expert here and though I have already compiled own sources
or installed gentoo (etc) and custom kernels (all stuff some people find difficult) I am not very "experienced" with some terms
of your posting:

stock kernel?? What do you mean by it. Is this the kernel that came from the device manafactuere preinstalled? (i.e. the AOSP kernel???)

kernel parition. I know what a partition is. I know what a kernel is. I can figure what a kernel partition is, sure.
In terms of memory on a smartphone... I get confused tough. Is this supposedly located on the internal memory and inaccessible?
Is is usual that by using Replicant (free software) we evenetually can access all from the device?
Or is this kernel partition stuff something that cannot be altered?? i.e more like a firmware, then like a data partition?

Thank you very much for the answer/posting Paul

RE: Trying out Replicant... (dual boot, revert to CM or to Android?) - Added by Paul Kocialkowski about 6 years ago

Well, Replicant doesn't have more features and improved hardware support as it is generally the case with Rockbox. Replicant won't bring exciting new features and has the (only) advantage of being entirely free. If you value that more than anything else, then you'll find that Replicant wins over the rest.

Stock kernel is the kernel that is preinstalled on the phone. We call the Android version that comes preinstalled with the phone "stock Android" as well.
Kernel partition: the phone's memory is divided in partitions (it has the same sense as partitions on a regular hard drive on x86 platforms), one of them holds the kernel, another one holds the bootloader, another the system, then another for the user data and so forth. The memory is not inaccessible since most of the time, the bootloader makes it possible to reflash these partitions by sending the new content to flash through USB. This is how you install another operating system on the phone. We call that "flashing" the phone.

As for access to the memory from the system, it depends on whether you can get root access or not. If not, then you cannot access and reflash the memory from the system, but we usually don't reflash the partitions from the system anyway since they are in use (by the system). Replicant comes with root access.