Beginner here.
I already know the difference between stock ROM/firmware and custom ROM, and why they're called such.
What I don't know is why overwriting the stock ROM with a custom ROM is called flashing, as is with flashing a recovery.
Regarding stock recovery and custom recovery, why is it called recovery? What exactly are we recovering? Also, is the recovery the cellphone equivalent of BIOS?
Thanks guys.
This maybe a bit of a geeky reply from an old timer, sort of along the reasons why we call it "rooting" a phone...
ROM stands for Read Only Memory and the original ones could NOT be written to or could only be written to once (fuse ROMs). Eventually we got EPROMs (Erasible Programmable Read Only Memory) that could be erased with an ultriviolet light and programmer (I still have one of those). Then came the EEPROMs (Electronically Erasible Programmable Read Only Memory) which were the forerunners to the modern flash ROM memory. They could be erased and reprogrammed without removing them from their circuilt. That evolved into the Flash ROMs, typcally NAND ROMs, which can be erased and reprogrammed (flashed) in blocks. So, flashing is simply the term for erasing those blocks of flash ROMs (typically several K at a whack) and programming it with the new data. Why the term "flashing" was chosen for that operation I believe had something to do with the way the NAND or NOR cells worked.
AFA Recovery goes, well, recovery is the inverse of backup. You back something up and, in the case of a disaster, you recover a device (computer, phone, whatever) by restoring that backup. The recovery ROMS have the ability to back up the device and restore (recover) the device. Makes sense.
thanks mhwarfield!
Related
I said I would flash cyanogenmod on a friends G1 because he was fed up with 1.6. I've flashed many custom ROM's on several different devices before but I've made a mess of things with this G1 and I can hardly hand back an unusable phone so I would really appreciate your help.
I rooted the phone using Androot, backed up the apps and settings using titanium backup and then the texts using a text backup app. I then downloaded Rom manager and flashed the latest clockworkmod recovery. Next I downloaded the latest official cyanogenmod rom for the dream/g1 and placed it on the phones SD card using my computer. I then re-opened rom manager and used it to select the zip file from the sd (to flash it) on prompt I checked two boxes one to wipe data and one to wipe the dalvik cache and pressed ok.
The phone rebooted into the recovery wiped the stuff, supposedly flashed the rom and rebooted. However it got stuck on the t-mobile g1 boot screen(it never showed anything else first or anything after) I left it for ages with no joy. I then tried wiping from the recovery and flashing again - same thing so i put cm5 on and tried flashing that. Same problem. Then i realised that it probably would not work because I would need to use DangerSPL as the /system partition is too small on the dream/g1. To be honest at this point I can't be bothered with to do that and this guy will be happy with anything above 1.6 to be honest so I thought I would try and flash CM4 because that's based on Eclair I believe (and so it not require I use DangerSPL or any other method to repartition the NAND). However, I tried it twice and still no luck.
At this point I'm somewhat panicking as I cannot seem to make the phone boot and it isn't even mine! Is anyone able to help?
Anyone? Please?
Look, at this stage I will forget custom roms etc. If anyone can tell me the easiest way to get this phone booting android again i would be very grateful.
Even if you could just tell me exactly how to restore it to stock 1.6 from here?
I have flashed roms on phones before - never had a problem but this is driving me crazy - please help!
wollac11 said:
Hi I said I would flash cyanogenmod on a friends G1 coz he was pissed off with 1.6 but im having trouble and I can hardly hand back an unusable phone so i really need your help.
I rooted the phone using Androot, backed up the apps and settings using titanium backup and then the texts using a text backup app. I then downloaded Rom manager and flashed the latest clockworkmod recovery. Next I downloaded the latest official cyanogenmod rom for the dream/g1 and placed it on the phones SD card using my computer. I then re-opened rom manager and used it to select the zip file from the sd (to flash it) on prompt I checked two boxes one to wipe data and one to wipe the dalvik cache and pressed ok.
The phone rebooted into the recovery wiped the stuff, supposedly flashed the rom and rebooted. However it got stuck on the t-mobile g1 boot screen(it never showed anything else first or anything after) I left it for ages with no joy. I then tried wiping from the recovery and flashing again - same thing so i put cm5 on and tried flashing that. Same problem. Then i realised that it probably would not work coz i would need to use DangerSPL coz the /system partition is too small on the dream/g1. Tbh i'm tired so I cba to do that and this guy is not that technical so he will be happy with anything above 1.6 so I thought I do CM4 coz thats 2.0 or 2.1 i seem to remember (and it not require I use DangerSPL) - tried it twice and still not luck.
HOW THE HELL CAN A GET THIS STUPID THING TO WORK AGAIN!??
MAJOR PANIC AS THIS IS NOT MY PHONE - PLEASE HELP!!!
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Click to collapse
Try this thread: http://forum.xda-developers.com/showthread.php?t=803482. I hope it helps.
It's been way too long since I rooted mine to be of any real help but I shall try nonetheless.
Firstly, there is a guide in the G1 forum to unroot and get back to stock firmware: Here (but note that I've never done this).
I must stress though (admittedly from memory) that if you have flashed an SPL or radio image at all, be VERY careful about the order in which you revert back to stock (or go to get a custom ROM depending on which way you decide to go). The G1 is very picky, and flashing things (mostly SPL and radio IIRC) in the wrong order will brick the device. That said, if you follow the instructions you find to the letter you should be OK. But yeah, read twice, flash once.
There is a lot of information in the stickies in the G1 forum. It could take a while to wade through but it should all be there. Failing that, post in the Q&A or General G1 subforums and I'm sure a current user will help you out.
I apologise if I've just posted a bunch of stuff you already know/have read - like I said, I've not used the phone in a while - just trying to offer what I can.
Thanks
No worries now guys i've done it! It was quite complicated but its all sorted now. If anyone is trying this and has the same (or similar) issue then pm me and I will tell you how I sorted it.
Otherwise thanks guys and you can conciser this thread:
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I have searched the forums and it seems no one has asked this yet.
So I know this giraffe that has 2 Inspire 4g phones, the giraffe rooted them and told me that when it loads up the operating system it has two different numbers on each.
Since the giraffe used the exact same method for rooting both phones, the giraffe wondered why the numbers were different.
Under the HBOOT menu Image CRC, the phone with the 1.34 OS vs the 1.74 OS number has a different CRC for the boot image - 0x1655xxxx vs 0x3845...
So the giraffe was wondering if the boot and system images are generated or changed according to the phone? So that they will always be different on every system. The giraffe thought that the boot CRC should be the same at least if you flashed the exact same ROM on the exact some phone model.
Just wondering what you guys thought?
The giraffe was thinking that it seems like there is two OS's layered on top of each other. The only difference the giraffe took on the second phone was that it went straight from 1.34 stock rooted to a custom ROM (with a boot.img), whereas on the first phone the giraffe rooted 1.34 software then upgraded to the 1.74 OTA update and rooted that, then installed a ROM from here.
Is it possible that certain files got updated via the first method 1.34 -> 1.74 -> custom rom vs 1.34 -> custom rom as in the second method? The giraffe was confused on the issue.
I also asked the giraffe if it wiped and cleared all cache and data between roms and it said yes.
This substitution of names confused me too much to even understand the question.. Maybe im slow..
Mindfuck: (checkmark)
Yeah what is this SWIM ****?
Sent from my Inspire 4G using XDA App
You don't have to be insulting, and the SWIM stuff is because I don't know the legality of implicating myself or others in breaking the protection on a phone.
I will simplify it for you.
Why is the boot.img displaying a different CRC after being flashed to the same model of phone?
I thought the boot partition was mounted as read only.
The phone that went from OS 1.34 --> straight to custom rom has rebooting issues, and it stops working in the middle of the night. It also can not do a CRC checksum of the system partition except 1 out of 5 tries. Something is not right with it. I am trying to determine if I should have flashed up in sequence through all the OTA upgrades as opposed to just going from the oldest OS straight to a custom ROM.
Capiche?
The flashing of a boot.img has nothing to do with it. The boot.img I think your getting mixed up thinking that it replaces the bootloader? Our boot.img's contain ONLY the kernel and ramdisk, nothing more. There probably different as a result of one of the phones receiving the ota, which I guess probably changes more partitions than a custom rom, including the bootloader(and crc) .
My phone hasn't officially been updated since the day it was bought, the only thing I've done is replace the bootloader with the eng. one, to get eng s-off so I could use fastboot.
The reboot problems are most likely coincidence, probably hardware related
Thank you for the reply... This kind of confirms my theory that I should probably return the phone before the warranty expires. It just is too unstable compared to the exact same phone that was purchased with it. One never reboots or locks, and the other locks up all the time.
I was thinking maybe it had something to do with the fact that I flashed all the progressively newer OTA updates to my first phone (which has no problems).
The second phone I got lazy and just put a custom rom on right after downgrading it.
I was debating on whether I should flash all the OTA updates on the second phone re-root it and see if the reboot issues don't clear up. Now I am thinking I should just exchange it and save myself some time.
Anyway, thanks for the help.
Hey friends,
I tried to upgrade and flash my tf to the newest ARHD or Revolver ics roms yesterday, coming from Prime 2.1. Therefore I wanted to use my rogue cwm recovery and made sure to wipe the tablet before i started to flash.
At first I thought, the light edition of the full wipe script from ARHD would do, but neither of both roms mentioned came beyond the first screen (nvidia tegra etc.) after installation.
Then I tried the wipe function of cwm, but that simply did what the script did I believe (leaving the internal storage untouched), which didn't succeed, too.
Finally I wiped my tablet with the "real" full wipe script and tried installing again, and again without any success.
So I used a nvflashable version of the stock ics i found in this forum (I have a B50), which eventually resulted in a working ics installation. I gave each of the other roms up to 10 minutes for the first screen before I stpped the try, and stock ics skipped this screen after 2 seconds after its successful installation.
I remembered, that I already had this behaviour when I was trying to flash a custom rom first, right after I rooted it, but with a different recovery back then (must have been roach's).
So I wanted to ask you if you have any ideas why this happens. I mean, I don't believe that it's all because of bad flashs. Both roms were stored in different locations, one on the sd, one on the internal memory. It's very inconvenient that I always have to wipe all partitions including the internal storage when I want to change my rom and there are only the roms available to me which have a nvflash version.
Thank you in advance, I hope I didn't write too much.
This is my first Samsung phone - had an HTC incredible, then a motorola bionic. I'm a veteran regarding flashing, rooting, etc - but, as many of you know, each device has it's own nomenclature and quirks - so, I'm getting my feet wet. I familiarized myself but had a couple more questions.
I followed this thread first:
http://forum.xda-developers.com/showthread.php?t=1974114
Decided to install latest leaked image - then rooted and unlocked and flashed TWRP. No issues, works great. This had me on VRBMA2.
I got squirrley for a new experience - only took me maybe 24 hours - so, decided to flash a ROM or two. Stuck with stock ROMs based off VRBLK3, CleanROM and Synergy. Both flashed fine, no big issues. I did note however that baseband still read VRBMA2. Because I've had the Bionic for so long with it's *$*%*$* locked bootloader, the idea of flashing custom kernel's and radios is foreign to me. I PRESUME, the baseband is the radio, but I don't know. I realized it was probably ideal to have the VRBLK3 baseband, but, since it was still JB, figured SHOULD be ok. Which it was in general, but, I wasn't sure - so I went back to stock via openyoureyes thread above.
So
1. Can someone clarify the importance of matching the baseband with what the ROM is based off of? How does this relate to non-stock ROMs? i.e. AOSP, AOKP, CM. I'm 99 % sure I've read that the ROM does not modify the baseband or the kernel.
(( 2. openyoureyes files do not modify data (I presume he means data folder with system apps). If I wanted to go back to square one - I presume the image files that he has 'hidden' and warns about using are the original image files to flash via ODIN if I want stock stock. (analagous to an SBF or FXZ file in a motorola device. He just has such serious warnings I wanted to be sure.
** Answered question 2 myself via here -- http://forum.xda-developers.com/showthread.php?t=1762709 section 5 *** ))
Thanks in advance. I love this phone and am having fun learning another device.
MrRedPants said:
This is my first Samsung phone - had an HTC incredible, then a motorola bionic. I'm a veteran regarding flashing, rooting, etc - but, as many of you know, each device has it's own nomenclature and quirks - so, I'm getting my feet wet. I familiarized myself but had a couple more questions.
I followed this thread first:
http://forum.xda-developers.com/showthread.php?t=1974114
Decided to install latest leaked image - then rooted and unlocked and flashed TWRP. No issues, works great. This had me on VRBMA2.
I got squirrley for a new experience - only took me maybe 24 hours - so, decided to flash a ROM or two. Stuck with stock ROMs based off VRBLK3, CleanROM and Synergy. Both flashed fine, no big issues. I did note however that baseband still read VRBMA2. Because I've had the Bionic for so long with it's *$*%*$* locked bootloader, the idea of flashing custom kernel's and radios is foreign to me. I PRESUME, the baseband is the radio, but I don't know. I realized it was probably ideal to have the VRBLK3 baseband, but, since it was still JB, figured SHOULD be ok. Which it was in general, but, I wasn't sure - so I went back to stock via openyoureyes thread above.
So
1. Can someone clarify the importance of matching the baseband with what the ROM is based off of? How does this relate to non-stock ROMs? i.e. AOSP, AOKP, CM. I'm 99 % sure I've read that the ROM does not modify the baseband or the kernel.
2. openyoureyes files do not modify data (I presume he means data folder with system apps). If I wanted to go back to square one - I presume the image files that he has 'hidden' and warns about using are the original image files to flash via ODIN if I want stock stock. (analagous to an SBF or FXZ file in a motorola device. He just has such serious warnings I wanted to be sure.
Thanks in advance. I love this phone and am having fun learning another device.
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Click to collapse
Welcome to the SGS3 :good:
1. Yes, baseband = radio. Any baseband can go with any rom (AOSP or TW). They are separate and not interrelated. I tend to keep mine flashed to the current newest, but use whichever one gives you best reception in your area. It's very subjective and what works for me may not be what works best for you. Flash away
2. The data he talks about is the /data/app folder (all the user apps you have installed from the Play store or otherwise) and the /data/media folder (your internal SD card). All the system apps (camera, contacts, email, phone, etc) are in the /system/app folder, which is part of the /system partition that gets overwritten when you flash the images in his thread. To go back to stock stock, as you put it (stock recovery, unrooted, locked bootloader), look at Section 5 in the OP here.
The difference between the openyoureyes files and the ones in droidstyle's is that droidstyles wipes your internal SD (you lose everything on the internal sd - it doesn't touch the external sd) and openyoureyes does not wipe the internal.
Hope that helps.
MrRedPants said:
So
1. Can someone clarify the importance of matching the baseband with what the ROM is based off of? How does this relate to non-stock ROMs? i.e. AOSP, AOKP, CM. I'm 99 % sure I've read that the ROM does not modify the baseband or the kernel.
Click to expand...
Click to collapse
Welcome aboard!
Basically there isn't any importance with matching your baseband with your rom. Just use whichever you think improves your signal the best. Fyi, you may see these terms thrown around a lot so to clarify: baseband = radio = modem. Your baseband is not flashed when you flash custom roms which is why you saw it stay the same. It will change if you Odin flash a stock rom.
2. openyoureyes files do not modify data (I presume he means data folder with system apps). If I wanted to go back to square one - I presume the image files that he has 'hidden' and warns about using are the original image files to flash via ODIN if I want stock stock. (analagous to an SBF or FXZ file in a motorola device. He just has such serious warnings I wanted to be sure.
Thanks in advance. I love this phone and am having fun learning another device.
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Click to collapse
What you'll want to look out for is whether the stock rom tar will format /sdcard. Open1your1eyes0 has hidden those in his thread I believe. At this point, each of the primary threads that contain Odin specific stock tar detail whether flashing them wipes /sdcard or not. With /sdcard being your internal storage, most user data is stored at /sdcard/data. You're external sd card will not be wiped when using a full wipe Odin tar.
Also, anything ending in ".tar" or ".tar.md5" is flashed only with Odin.
Sent from my SCH-I535 using xda app-developers app
Battery life
Camera
Performance
Another Question:-
Is there any problem for rooting many times as we flash custom roms over again again?
I meant that efs would be lost (imei)
Is there any fi for that also
Please let me know if it safe for efs or not also
There is no such thing as a "best rom" I would suggest checking out the relevant custom roms forum for your specific device. Have a read about the roms and users reviews and select one which you think would be the best for you to use.
As for "efs" lost I'm not an expert but I've flashed many devices with cutom roms and never lost my imei, if you are not comfortable with flashing a rom then I suggest sticking to the stock rom, if you do decide to go ahead and flash a rom I suggest making a full backup in recovery custom recovery like "twrp" allow you to backup everything including the efs. I learnt from my mistake of not making a backup thinking everything will be smooth sailing I lost all my sentimental data. Always make a backup.