Please take some time to read patiently everything. As always i`m not responsable for any damage that you do to your device.
Hello guys, i want to share some info with you. As recognised devs say from time to time, we just need to think outside the box, everything is there for us to read/learn. I`m gonna debate in this post 3 issues that i had and the workaround for them:
1. OMC code changing wants to wipe data..
But who will agree to that without a fair fight? I investigated the frameworks and found out that samsung sets country code to use from the mcc/mnc of the sim card inserted. Inside efs/imei should be a country code file named mps_code.dat, which it contains some code. Usually at the first boot framework is creating a new file in there named omcnw_code.dat containing sim card code.. After booting, it compares both files mps_code.dat and omcnw_code.dat and if the string inside doesn`t match, it prompts for a reboot to apply the country or reboot to factory reset to use new sim. Now, if you don`t have stock recovery to securely perform the wipe, you`ll probably end in bootloop. First time i ended in bootloop because of twrp, second time i mounted efs from twrp and manually changed the mps_code.dat according to sim country. Booted up and all just was ok, without the wipe that samsung added.
Therefore i tried to make a method inside SystemServer.smali (services.jar/smali/com/android/servers) that loads at boot, looks for the omcnw and if it`s found, it will delete mps_code.dat and rename omcnw_code.dat to mps_code.dat, so you won`t feel the change but also no more wipe prompt.
Under the # direct methods, anywhere after .method public constructor <init>()V i added this method:
And ofc now we need an invoke for this method.
I added it in .method private run()V after loading libandroid_servers
After this, no more prompt about wipe to use the sim.
2. OMC is a pain when it comes to add features..
I wanted to add csc features but either omc was encrypted (which has a solution now), or either way too many xmls to edit.. Investigated a bit SemCscFeature.smali (framework.jar/smali_classes3/samsung/android/feature) and gave me an idea that actually worked.
The point was to duplicate loadNetworkFeatureFile method, rename it, point it to certain location where we will add a single xml file containing all the features we want and add the invoke right after loadNetworkFeatureFile invoke. By doing this, doesn`t matter what csc is loaded, the system will load our custom xml too. Less time to add features, cleaner way to load, and it doesn`t even need to decrypt omc. And by using a duplicate of loadNetworkFeatureFile we can encrypt our xml too
.
I`m gonna post my methods too, might be a bit sloppy code, i lost myself inside of it, but as long as it does what it`s supposed, doesn`t matter anymore :laugh:
Gonna hide the method as it is a long one
And the invoke:
The code can be simplified, i didn`t bothered to do that, feel free to manipulate it in which way you want.
3. Use ODM instead of OMC/CSC in Oreo
From S9 Samsung introduced a new kind of omc, ODM, which needs its own partition and needs to be loaded from fstab/dts. We can add it to non ODM devices with a pretty simple and clean workaround.
Inside ramdisk, in init.rc file (all the devices should have that), i found this:
Following this we can make it work just like this:
By unpacking odm partition content inside a folder from system and creating the symlink from above at boot, rom will load odm as it has the partition.
Hope these tips will help someone in the future of custom roms with more features.
I will attach to this thread my modified smalis from one of my roms, i tried these methods on 7.1.1, but the idea is the same for oreo too, code might be slighlty different.
All the best :fingers-crossed:
Hello guys, i want to share some info with you. As recognised devs say from time to time, we just need to think outside the box, everything is there for us to read/learn. I`m gonna debate in this post 3 issues that i had and the workaround for them:
1. OMC code changing wants to wipe data..
But who will agree to that without a fair fight? I investigated the frameworks and found out that samsung sets country code to use from the mcc/mnc of the sim card inserted. Inside efs/imei should be a country code file named mps_code.dat, which it contains some code. Usually at the first boot framework is creating a new file in there named omcnw_code.dat containing sim card code.. After booting, it compares both files mps_code.dat and omcnw_code.dat and if the string inside doesn`t match, it prompts for a reboot to apply the country or reboot to factory reset to use new sim. Now, if you don`t have stock recovery to securely perform the wipe, you`ll probably end in bootloop. First time i ended in bootloop because of twrp, second time i mounted efs from twrp and manually changed the mps_code.dat according to sim country. Booted up and all just was ok, without the wipe that samsung added.
Therefore i tried to make a method inside SystemServer.smali (services.jar/smali/com/android/servers) that loads at boot, looks for the omcnw and if it`s found, it will delete mps_code.dat and rename omcnw_code.dat to mps_code.dat, so you won`t feel the change but also no more wipe prompt.
Under the # direct methods, anywhere after .method public constructor <init>()V i added this method:
Code:
.method private static deleteOmcnw()V
.locals 5
const-string/jumbo v2, "/efs/imei/omcnw_code.dat"
const-string/jumbo v3, "/efs/imei/mps_code.dat"
new-instance v0, Ljava/io/File;
invoke-direct {v0, v2}, Ljava/io/File;-><init>(Ljava/lang/String;)V
if-eqz v0, :cond_0
invoke-virtual {v0}, Ljava/io/File;->exists()Z
move-result v1
if-eqz v1, :cond_0
new-instance v1, Ljava/io/File;
invoke-direct {v1, v3}, Ljava/io/File;-><init>(Ljava/lang/String;)V
if-eqz v1, :cond_0
invoke-virtual {v1}, Ljava/io/File;->exists()Z
move-result v4
if-eqz v4, :cond_0
invoke-virtual {v1}, Ljava/io/File;->delete()Z
invoke-virtual {v0, v1}, Ljava/io/File;->renameTo(Ljava/io/File;)Z
:goto_0
return-void
:cond_0
const-string/jumbo v0, [COLOR="Blue"]"omcnw"[/COLOR]
const-string/jumbo v1, [COLOR="Blue"]"Some log lines, blah blah blah"[/COLOR]
invoke-static {v0, v1}, Lcom/android/server/utils/sysfwutil/Slog;->e(Ljava/lang/String;Ljava/lang/String;)I
goto :goto_0
.end methodI added it in .method private run()V after loading libandroid_servers
Code:
invoke-static {v0}, Landroid/os/Process;->setCanSelfBackground(Z)V
invoke-static {}, Landroid/os/Looper;->prepareMainLooper()V
const-string/jumbo v0, "android_servers"
invoke-static {v0}, Ljava/lang/System;->loadLibrary(Ljava/lang/String;)V
[COLOR="Blue"]invoke-static {}, Lcom/android/server/SystemServer;->deleteOmcnw()V[/COLOR]
invoke-direct {p0}, Lcom/android/server/SystemServer;->performPendingShutdown()V
invoke-direct {p0}, Lcom/android/server/SystemServer;->createSystemContext()V
new-instance v0, Lcom/android/server/SystemServiceManager;2. OMC is a pain when it comes to add features..
I wanted to add csc features but either omc was encrypted (which has a solution now), or either way too many xmls to edit.. Investigated a bit SemCscFeature.smali (framework.jar/smali_classes3/samsung/android/feature) and gave me an idea that actually worked.
The point was to duplicate loadNetworkFeatureFile method, rename it, point it to certain location where we will add a single xml file containing all the features we want and add the invoke right after loadNetworkFeatureFile invoke. By doing this, doesn`t matter what csc is loaded, the system will load our custom xml too. Less time to add features, cleaner way to load, and it doesn`t even need to decrypt omc. And by using a duplicate of loadNetworkFeatureFile we can encrypt our xml too
.I`m gonna post my methods too, might be a bit sloppy code, i lost myself inside of it, but as long as it does what it`s supposed, doesn`t matter anymore :laugh:
Gonna hide the method as it is a long one
Code:
...
invoke-direct {p0, v2, v4}, Lcom/samsung/android/feature/SemCscFeature;->loadFeatureFile(ZLjava/lang/String;)Z
move-result v5
if-eqz v5, :cond_1
invoke-direct {p0, v2, v3}, Lcom/samsung/android/feature/SemCscFeature;->loadNetworkFeatureFile(ZLjava/lang/String;)V
[COLOR="Blue"]invoke-direct {p0, v2, v3}, Lcom/samsung/android/feature/SemCscFeature;->loadHadesFeatureFile(ZLjava/lang/String;)V[/COLOR]
:try_end_0
.catch Ljava/lang/Exception; {:try_start_0 .. :try_end_0} :catch_0
...3. Use ODM instead of OMC/CSC in Oreo
From S9 Samsung introduced a new kind of omc, ODM, which needs its own partition and needs to be loaded from fstab/dts. We can add it to non ODM devices with a pretty simple and clean workaround.
Inside ramdisk, in init.rc file (all the devices should have that), i found this:
Code:
# Link /vendor to /system/vendor for devices without a vendor partition.
symlink /system/vendor /vendor
Code:
# Link /vendor to /system/vendor for devices without a vendor partition.
symlink /system/vendor /vendor
[color="Blue"] symlink /system/odm /odm[/color]Hope these tips will help someone in the future of custom roms with more features.
I will attach to this thread my modified smalis from one of my roms, i tried these methods on 7.1.1, but the idea is the same for oreo too, code might be slighlty different.
All the best :fingers-crossed:
Last edited:
