[Gta04-owner] Replicant images on GTA04 release

Paul Kocialkowski paulk at paulk.fr
Fri Sep 14 21:57:51 CEST 2012

Le vendredi 14 septembre 2012 à 12:45 +0200, Radek Polak a écrit :
> On Friday, September 14, 2012 08:45:43 AM Paul Kocialkowski wrote:
> > > I quite dont like that the script deletes the whole SD card (or am i
> > > wrong?). I have 32GB uSD card with 24GB of data on it (mp3, images,
> > > videos, maps etc..)
> > 
> > You're absolutely right, the script will erase the SD card.
> In the end i found second SD card for experimenting. I tried the script, but 
> since the reader in my notebook reckognizes the sd card as /dev/mmcblk0 (and 
> the partitions are mmcblk0p1) it did not work. But i have modified it to 
> prepend "p" in front of partition number and now i got now the system SD card.

Indeed, the flasher script is made to to deal with /dev/sda1 type
devices. Perhaps it could be extended to support mmcblk as well, though
it seems quite uncommon on x86 computers.

> But i was quite surprised i even cant boot from this SD card. It requires me 
> to flash bootloader and kernel in NAND (or am i wrong?).
> Why? I can understand that android likes 3 partitions on SD card, but why it 
> needs even flashing stuff to NAND. I have in NAND goldelico's kernel and debian 
> that came with the phone and it's invaluable when i do something wrong with SD 
> card. Why does replicant requires to delete all non-android bits on the device 
> to start running? Is there any technical reason to flash NAND?

So let me explain a bit what's going on here:
the boot.scr script does flash the kernel to NAND, because I thought
it's the place it should be (mainly because there is no room for a
dedicated partition on uSD). However, it is possible to boot the kernel
from sdcard by setting the replicant_sdcard_boot to yes with setenv. 
The kernel must then be a file called "boot.img" placed at the root of
the system partition of the sdcard.
If it seems that inconvenient to you, maybe we could make this the
default behaviour.

It would indeed permit to keep another system on-NAND. Though, there
would be the boot.scr issue in order to decide which system to boot
(since you need a different boot.scr to boot replicant than to boot
debian). Then you need to flash one in order to boot replicant or
debian, so it's pretty much the same as flashing the kernel too.

Using some bootmenu wouldn't be such a great solution too because
distros on uSD will have the kernel in different places.

Then, the solutions could be not to flash boot.scr and leave it in the
first partition, required to be fat32, or to put the kernel in a
specific place on the uSD card (likely on the first fat32 partition as
well), that would be the same for all distros and that would be used by
the bootmenu.

> I think it will be quite hard for normal users to install normal distro again. 

I'm pretty sure that a normal install of any distro will erase the
current boot.scr and replace it by the provided one. I don't see what
the difference for the user would be.

> I spent many hours troubleshooting Freerunner users because of non standard 
> bootloader that Android on Freerunner was using. Could we please avoid this on  
> GTA04... 

The bootloader here is just a very standard uboot from goldelico tree.
It is provided in order to flash a more recent version than the one
currently on the device. I don't see why that could be a bad idea.
There is nothing non-standard in it like it was with qi on freerunner.

Paul Kocialkowski, Replicant developer

Replicant is a fully free Android distribution

Website:        http://www.replicant.us
Wiki/Tracker:   http://redmine.replicant.us

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