[Q] Understanding Android firmware updates - Galaxy S II Q&A, Help & Troubleshooting

I have a SGS2 with the default ROM the phone came with, and CF-Root installed with CWM v3.0.0.5. Specifically, this is what’s installed:
Baseband version: I9100XXKDJ
Kernel: version 2.6.35.7-I9100XWKE8-CL214845, [email protected]#2
I just launched Kies to check for a firmware update, and was told this:
Current firmware: PDA:KE2 / PHONE:KDJ / CSC:KE2 (NEE)
Latest firmware: PDA:KF3 / PHONE:KE7 / CSC:KF1 (NEE)
I don’t quite understand what constitutes the Android firmware as I’ve recently migrated from iOS where baseband (modem) and OS are the two versions one needs to keep in mind (or just OS, if you had an unlocked iPhone like I did) for a jailbreak/unlock. Thus a few questions:
1. What are the PDA, PHONE and CSC parts of the firmware?
2. Why are there so many types of firmware; if you look at Chainfire’s CF-Root post there’s a host of patched kernels. Are SGS2s sold in regions with varying hardware? With the iPhone there was one hardware version, one OS (Verizon excluded). Simple.
3. I want to flash a custom ROM (Batista70 based on 2.3.4) - what is the best way to make sure everything is up to date before I do this? I was thinking of letting Kies update (which I guess will remove my root access), then installing the latest version of CF-Root with CWM 4, and finally flashing the ROM from CWM. I have the relevant app data backed up with Titanium Backup.
Many thanks!

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Nitsson said:
I have a SGS2 with the default ROM the phone came with, and CF-Root installed with CWM v3.0.0.5. Specifically, this is what’s installed:
Baseband version: I9100XXKDJ
Kernel: version 2.6.35.7-I9100XWKE8-CL214845, [email protected]#2
I just launched Kies to check for a firmware update, and was told this:
Current firmware: PDA:KE2 / PHONE:KDJ / CSC:KE2 (NEE)
Latest firmware: PDA:KF3 / PHONE:KE7 / CSC:KF1 (NEE)
I don’t quite understand what constitutes the Android firmware as I’ve recently migrated from iOS where baseband (modem) and OS are the two versions one needs to keep in mind (or just OS, if you had an unlocked iPhone like I did) for a jailbreak/unlock. Thus a few questions:
1. What are the PDA, PHONE and CSC parts of the firmware?
2. Why are there so many types of firmware; if you look at Chainfire’s CF-Root post there’s a host of patched kernels. Are SGS2s sold in regions with varying hardware? With the iPhone there was one hardware version, one OS (Verizon excluded). Simple.
3. I want to flash a custom ROM (Batista70 based on 2.3.4) - what is the best way to make sure everything is up to date before I do this? I was thinking of letting Kies update (which I guess will remove my root access), then installing the latest version of CF-Root with CWM 4, and finally flashing the ROM from CWM. I have the relevant app data backed up with Titanium Backup.
Many thanks!
Click to expand...
Click to collapse
1. Pda is the basic firmware, Phone is the modem responsible for wifi/2g/3g, csc is the country specific code - language files/apps etc. You shouldn't consider these as separate, they all combine to make a single firmware (which will have the pda code)
2. There are multiple firmwares because they keep getting updated, the cf-root has multiple versions to accomodate those who haven't update to the latest. Usually the highest alphabetical and number code is the latest, currently kg3 i believe
3. Whatever kies updates, flashing a rom over it will overwrite anyway so there's no point using kies
Make a nandroid backup from cwm before you start flashing ROM in case something goes wrong

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Ok, so neither pda, phone or scs constitute the kernel? I appreciate that custom ROMs incorporate the official (and sometimes the unofficial) Samsung releases meaning I don't need to faff around with Kies, but CF-Root handles only the kernel if understand it correctly.
In Chainfire's guide on rooting, specifically the but on getting rid of the warning triangle, he says "Find an original Samsung signed stock kernel (preferably from the same stock firmware you have, but it's not terribly important)" which I don't understand. How can I find a kernel, all I have are ROMs which as I understand it do not include the kernel.

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Nitsson said:
Ok, so neither pda, phone or scs constitute the kernel? I appreciate that custom ROMs incorporate the official (and sometimes the unofficial) Samsung releases meaning I don't need to faff around with Kies, but CF-Root handles only the kernel if understand it correctly.
In Chainfire's guide on rooting, specifically the but on getting rid of the warning triangle, he says "Find an original Samsung signed stock kernel (preferably from the same stock firmware you have, but it's not terribly important)" which I don't understand. How can I find a kernel, all I have are ROMs which as I understand it do not include the kernel.
Click to expand...
Click to collapse
here is all the roms and kernels
if you read closely under each rom their is also a link for kernels.
http://forum.xda-developers.com/showthread.php?t=1075278

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Nitsson said:
Ok, so neither pda, phone or scs constitute the kernel? I appreciate that custom ROMs incorporate the official (and sometimes the unofficial) Samsung releases meaning I don't need to faff around with Kies, but CF-Root handles only the kernel if understand it correctly.
In Chainfire's guide on rooting, specifically the but on getting rid of the warning triangle, he says "Find an original Samsung signed stock kernel (preferably from the same stock firmware you have, but it's not terribly important)" which I don't understand. How can I find a kernel, all I have are ROMs which as I understand it do not include the kernel.
Click to expand...
Click to collapse
Kernel is a (small) part of PDA. So flash PDA replaces the kernel. But you can flash kernel separately without changing the other parts of PDA.
Sent from my GT-I9100 using Tapatalk

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zabihjan said:
here is all the roms and kernels
if you read closely under each rom their is also a link for kernels.
http://forum.xda-developers.com/showthread.php?t=1075278
Click to expand...
Click to collapse
tjtj4444 said:
Kernel is a (small) part of PDA. So flash PDA replaces the kernel. But you can flash kernel separately without changing the other parts of PDA.
Sent from my GT-I9100 using Tapatalk
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Click to collapse
Great, thanks. So if I flash a custom ROM based on KG2, do I need to flash the ROM first followed by CF-Root? I imagine that if I flash CF-Root first and then the customer ROM via CWM, this will overwrite portions of CF-Root which is needed for CWM etc.

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Nitsson said:
Great, thanks. So if I flash a custom ROM based on KG2, do I need to flash the ROM first followed by CF-Root? I imagine that if I flash CF-Root first and then the customer ROM via CWM, this will overwrite portions of CF-Root which is needed for CWM etc.
Click to expand...
Click to collapse
CF-Root (flashed through Odin) is the 1st step in running a custom rom. The kernel will replace the stock samsung recovery with the clockworkmod recovery which is then used to flash custom ROMs
Custom ROMs may replace the CF-Root kernel but no responsible dev would include a kernel that removes the CWM recovery so you do not need to worry about overwriting it.
On a side note, in an original full stock rom (in tar format) the zImage file within the tar is the kernel, if you wanted to flash the original kernel back then you would remove all the other files from the tar (and leave zImage) and flash the tar in Odin as PDA.. although this wouldn't be a great idea as it would remove the custom CWM recovery

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About point 3 - flashing a rom is the 'update'. Forget about KIES when you start flashing your roms, because all of the software is in there, the rom itself.

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viva.fidel said:
CF-Root (flashed through Odin) is the 1st step in running a custom rom. The kernel will replace the stock samsung recovery with the clockworkmod recovery which is then used to flash custom ROMs
Custom ROMs may replace the CF-Root kernel but no responsible dev would include a kernel that removes the CWM recovery so you do not need to worry about overwriting it.
Click to expand...
Click to collapse
viva.fidel said:
On a side note, in an original full stock rom (in tar format) the zImage file within the tar is the kernel, if you wanted to flash the original kernel back then you would remove all the other files from the tar (and leave zImage) and flash the tar in Odin as PDA.. although this wouldn't be a great idea as it would remove the custom CWM recovery
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Click to collapse
Excellent, I get that part. Good explanation.
How about the order of flashing; the custom ROM I want to try is based on KG3, and I also want to flash the updated CF-Root v.4.1 KG3 kernel followed by the stock Samsung kernel to rid myself of that warning triangle (any future flashing I will do through CWM and not Odin). Should I install the custom ROM via my current version of recovery, then, upgrade CF-Root via the patched KG3 kernel, and finally flash the stock Samsung KG3 kernel?
Since I'm using KE2 at the moment, I'm thinking that flashing just a KG3 kernel to get CF-Root 4.1 isn't a best idea, as the KE2 firmware overall might not be compatible with a KG3 kernel.

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Custom rom has to be installed as per each developers instructions for each individual rom .Not all are CWM flashable .
Personnel i would upgrade the CF root to the later verion before rthe custom rom but i would also read the details of the rom has it may have the latest CWM installed .
jje

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Nitsson said:
Excellent, I get that part. Good explanation.
How about the order of flashing; the custom ROM I want to try is based on KG3, and I also want to flash the updated CF-Root v.4.1 KG3 kernel followed by the stock Samsung kernel to rid myself of that warning triangle (any future flashing I will do through CWM and not Odin). Should I install the custom ROM via my current version of recovery, then, upgrade CF-Root via the patched KG3 kernel, and finally flash the stock Samsung KG3 kernel?
Since I'm using KE2 at the moment, I'm thinking that flashing just a KG3 kernel to get CF-Root 4.1 isn't a best idea, as the KE2 firmware overall might not be compatible with a KG3 kernel.
Click to expand...
Click to collapse
which rom are you trying to flash? If it needs to be flashed through cwm then you'll have to flash a custom kernel through odin first to give you cwm recovery (custom rom can't be flashed with the stock samsung recovery), then flash the rom in cwm. Does the rom include cf-root? If it doesn't then flash the cf-root kernel and then the stock kernel to get rid of the triangle
If the rom can be flashed through odin then you can skip flashing the initial cwm-enabling ke2 kernel
Sent from my GT-I9100 using XDA App

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JJEgan said:
Custom rom has to be installed as per each developers instructions for each individual rom .Not all are CWM flashable .
Personnel i would upgrade the CF root to the later verion before rthe custom rom but i would also read the details of the rom has it may have the latest CWM installed .
Click to expand...
Click to collapse
Ok thanks. I also think that I should install the latest version of CF-Root first.
viva.fidel said:
which rom are you trying to flash? If it needs to be flashed through cwm then you'll have to flash a custom kernel through odin first to give you cwm recovery (custom rom can't be flashed with the stock samsung recovery), then flash the rom in cwm. Does the rom include cf-root? If it doesn't then flash the cf-root kernel and then the stock kernel to get rid of the triangle
If the rom can be flashed through odin then you can skip flashing the initial cwm-enabling ke2 kernel
Click to expand...
Click to collapse
It's the Batista 3.2 ROM that I intend to flash. I already have CF-Root / recovery installed, and this ROM also installs recovery v4.0.1.4, but what I don't know if this is the same as the recovery included in CF-Root - most likely not.
I'll probably go ahead and will flash the custom CF-Root KG3 kernel and the stock KG3 kernel via Odin to get rid of the triangle, and finally the ROM via recovery. That should do it.

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Should be pinned. This was exactly was I wanted to know and maybe many others too.

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Nitsson said:
It's the Batista 3.2 ROM that I intend to flash. I already have CF-Root / recovery installed, and this ROM also installs recovery v4.0.1.4, but what I don't know if this is the same as the recovery included in CF-Root - most likely not.
I'll probably go ahead and will flash the custom CF-Root KG3 kernel and the stock KG3 kernel via Odin to get rid of the triangle, and finally the ROM via recovery. That should do it.
Click to expand...
Click to collapse
Think CF-Root comes with CWM 4.0.0.2
Looks like Batista's ROM includes a kernel.. you should therefore flash the ROM first, then CF-Root (so it overwrites the ROM kernel) and then the stock samsung-signed KG3 kernel

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viva.fidel said:
Think CF-Root comes with CWM 4.0.0.2
Looks like Batista's ROM includes a kernel.. you should therefore flash the ROM first, then CF-Root (so it overwrites the ROM kernel) and then the stock samsung-signed KG3 kernel
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Click to collapse
I did exactly that Just flashed the CF-Root kernel via the CWM app at the end to have all the goodies. Works a treat so far but I'll see over the coming weeks.