Custom ROM creation mentoring

[elektrik]

To all: I've decided to bite the bullet and try to figure out if I can create a custom ROM for our beloved Polaroid tablets, and I could use some mentoring assistance.

I have some of the pieces in place and currently I'm following a guide on XDA to get my kitchen setup, but in all honesty, I'm fairly ignorant when it comes to Android development, so this is a call to any folks who might be willing to assist me (currently I'm not sure how to deconstruct the .img file but I wonder if it's my kitchen..... (DSIXDA))....

Anyhow, to everyone else hoping to have an 'elektrik' ROM-don't get your hopes up-I get the feeling it's going to be a while, lol.

[900supersport]

Re: Custom ROM creation mentoring

A couple of questions

What processor do you have?

Do you have any experience with Linux?

We are a friendly bunch here so there should be some support available. Have you read this thread http://www.freaktab.com/showthread.p...ull=1#post3373

[elektrik]

A couple of questions

What processor do you have?

Do you have any experience with Linux?

We are a friendly bunch here so there should be some support available. Have you read this thread http://www.freaktab.com/showthread.p...ull=1#post3373

To answer in order:
- Intel CORE i5 vPro
- I do have linux experience-not the system admin type, but certainly I have (and currently use) at least an intermediate knowledge level (I have Ubunto 12.04.1 x64 installed in a VM).
- No I have not read that thread-reading now.

Thanks for the assistance!

[900supersport]

Is that the processor in the tablet?

[elektrik]

Is that the processor in the tablet?

Oh, sorry! I thought you were referring to my system specs! Mine is the Polaroid PMID701C. I believe it's the ARM Cortex A8.

[elektrik]

Ok, so I've copied the system.img to my folder, and I'm trying to mount it, but whenever I do I receive the error "mount: mount point system does not exist"

I've tried:

"sudo mount -o loop system.img system"
"sudo mount -t cramfs -o loop system.img system"

I suspect that the Polaroid ROM is using the 'crapfs' ( :-) ) that Finless is pointing out....unfortunately, I can't seem to get it to mount (I previously couldn't figure out how to update cramfs but I got the latest version-still didn't help :-( )

Not sure what I'm doing wrong :-(

[900supersport]

you did create a system folder first?

[elektrik]

you did create a system folder first?

Yessir!

[900supersport]

Re: Custom ROM creation mentoring

That error suggests the issue is with the mount point so let's check. From you terminal session enter ls and enter. You should see both your system.img and your system folder. If not you need to CD to the folder with these in.

[elektrik]

That error suggests the issue is with the mount point so let's check. From you terminal session enter ls and enter. You should see both your system.img and your system folder. If not you need to CD to the folder with these in.

Ok, your post clued me in. I was trying to mount the system.img INSIDE the system folder, which didn't work. I created both the system folder and made sure both the system.img and /system folder were visible when I tried to mount-so that part's fixed. Of course, now when I try to mount with the -t cramfs option I see this message:

"mount: you must specify the filesystem type
jhorgan@Ubuntu-A:/kitchen$ sudo mount -t cramfs -o loop system.img system
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so"

I used the dmesg command and here's the lines I think are pertinent:

"[ 5565.881842] cramfs: wrong magic
[ 5571.783892] cramfs: wrong magic"


I've tried doing various google searches on the solution (apprently what I originally thought-that the cramfs system is different for the Polaroid .img file), but can't seem to get any traction-sorry I'm such a noob at this supersport :-(

[900supersport]

Re: Custom ROM creation mentoring

I've had it easy in that the roms I've looked at are all ext3 or ext4.

Have you tried mounting as ext4 or ext2?

Other possibility is to use a terminal on the tablet and see if you can mount a copy of system.img on the tab, if so you could then copy to another folder and have the makings of an ext3 system.img.

[elektrik]

I've had it easy in that the roms I've looked at are all ext3 or ext4.

Have you tried mounting as ext4 or ext2?

Other possibility is to use a terminal on the tablet and see if you can mount a copy of system.img on the tab, if so you could then copy to another folder and have the makings of an ext3 system.img.

Ooh! all good ideas! I'll try those next and let you know.

[elektrik]

Ok, I've tried what you suggested: ext3/4 don't work on the Ubuntu system, however I *may* be able to get it to mount on the tablet itself. I've tried the mount command as follows: "mount -o loop system.img system" with the 'system.img' and 'system' folder together in a folder, however I keep getting a syntax error message that says "Usage: mount [-r] [-w] [-o options] [-t type] device directory"....

UPDATE: Ok, I've gotten a bit further on the tablet-it now says 'ioctl LOOP_SET_FD failed: Device or resource busy'. wondering if it's because I'm doing it on the extsd......

[900supersport]

Re: Custom ROM creation mentoring

Are you certain it mounts cramfs? Check from a terminal session by entering mount, look for the line that mounts system.

[elektrik]

Are you certain it mounts cramfs? Check from a terminal session by entering mount, look for the line that mounts system.

Not sure what you mean. I typed the following in terminal on the tablet (I duplicated it with adb (apparently no difference whether actually on the tablet or using adb)):

root@android:/mnt/extsd/Tmp # mount -r -w -t cramfs -o loop system.img system
mount -r -w -t cramfs -o loop system.img system
ioctl LOOP_SET_FD failed: Device or resource busy
1|root@android:/mnt/extsd/Tmp #