My son-in-law just got SDS on his stock Note 2 7100, and I want to Prevert or delay SDS on my own stock note 2.
I am aware that samasung and a couple of custom kernel developers implemented solutions for SDS, but which it is very unclear where the fix was implemted.
Which filesyou recommend I flash to ensure that my note has a fix or at least a delay for the sds
mmk92 said:
My son-in-law just got SDS on his stock Note 2 7100, and I want to Prevert or delay SDS on my own stock note 2.
I am aware that samasung and a couple of custom kernel developers implemented solutions for SDS, but which it is very unclear where the fix was implemted.
Which filesyou recommend I flash to ensure that my note has a fix or at least a delay for the sds
Click to expand...
Click to collapse
Hi. Before you make panic test your device with "emmc check". Download it from the market.
Already did, it is affected
If you want to understand SDS, I think that you should take a look at this thread : http://forum.xda-developers.com/showthread.php?t=2096045
The idea is that when the eMMC is mounted, the kernel injects code that check for the SDS condition and respond by causing a freeze or reboot instead of permanent damage.
From a more practical standpoint, the patch is implemented in the kernel. The kernel may be part of a ROM of flashed separately. Also the recovery has its own kernel and must implement the patch too.
By now, official and most custom ROMs/kernel/recoveries are all patched so it is much less of a problem. If you really want to be sure, unroot and get the latest OTA. You can root it again if you wish : root and SDS are unrelated.
Related
All - following up on a post in AndroidForums which referenced a comment on the root story here. The comment (from Gee):
Correct me if I’m wrong, but I remember hearing that the drivers/kernel are either encrypted, unusable, or simply unavailable. Meaning that while you can root the Galaxy S and put custom ROMs, you still can’t put unofficial ROMs (like Cyanogen) on it without expecting to break a lot of functionality.
That means that you WONT be putting Froyo on it until Samsung officially releases the ROM which can then later be modified. And if Samsung moves away from the Galaxy S after that update, you’ll never see a fully functioning Gingerbread ROM. Ever. That’s a hard pill for me to swallow.
Click to expand...
Click to collapse
Can anyone shed further light on this?
Sounds counter productive. I heard they will be releasing source code. Would be odd if they kept the rest under wraps or took extra measures to prevent access....
Methinks this is definitely worth further investigation. Need some experienced SGS modders to find this thread...
From what I have seen, the drivers are provided in binary form only (which is basically the same as how drivers are provided on Windows). So long as there isn't some code written into the drivers that would prohibit their running on non-official ROMs, there shouldn't be any problem using the drivers in custom ROMs.
I downloaded the entire sourcecode from the samsung website. Its a 150MB zip file and everything is in there in binary form. It must be compiled. I'm certainly not a linux or android dev but it seems like thats what you need. There's even readme.txt files in there to tell you how to build new versions of software.
I'm wondering how long it'll take for someone to put out a custom ROM for the captivate based on 2.2?
Hi all! I just purchased 4 days ago my nexus 4 16Gb
Im quite happy with it but here are some questions: I'm just asking them because probably someone else has already gone through the same doubts and probably has some more experience: This device's forums have the fame of being more polite and tolerant than some other, so I hope you guys give me some feedback
I come from SGSII - I have ben using CM9 and 10.0 until it got bricked on november 2012
In the moment i received the new phone, i unlocked it, installed CWM Recovery and made a backup of the original ROM, then, installed CM10.1+franco kernel (both nightly)
The questions I have are:
1: Perhaps the low battery life has something to do with the fact that this is my new toy and I cannot stop playing with it, but I'm thinking about trying official ROM+ root.... would this improve the battery life?
2: The camera has been acting weird a couple of times: Once, the image was flickering: a reboot fixed it.... and another time, when i opened the camera app, would get a black screen. Im not very patient.... so I restarted and the problem is gone... Would official ROM fix this?
3: Which features do we have in stock rom that are not present on CM?
4: On stock rom, can you Root/Unroot and then re-lock the phone as if nothing happened? ¿Do you lose data if you do so?
5: There is a lot of confusion about this: When you unlock the phone, the disclaimer says that process "MIGHT" VOID THE WARRANTY..... does it void it or not?, what does that "might" mean?
Overall, the phone is wonderful and I'm really happy, I'm just thinking about testing stock rom but I don't want to lose functionality...
I'm waiting for your advice.
Thanks!!
GFXi0N said:
Hi all! I just purchased 4 days ago my nexus 4 16Gb
Im quite happy with it but here are some questions: I'm just asking them because probably someone else has already gone through the same doubts and probably has some more experience: This device's forums have the fame of being more polite and tolerant than some other, so I hope you guys give me some feedback
I come from SGSII - I have ben using CM9 and 10.0 until it got bricked on november 2012
In the moment i received the new phone, i unlocked it, installed CWM Recovery and made a backup of the original ROM, then, installed CM10.1+franco kernel (both nightly)
The questions I have are:
1: Perhaps the low battery life has something to do with the fact that this is my new toy and I cannot stop playing with it, but I'm thinking about trying official ROM+ root.... would this improve the battery life?
2: The camera has been acting weird a couple of times: Once, the image was flickering: a reboot fixed it.... and another time, when i opened the camera app, would get a black screen. Im not very patient.... so I restarted and the problem is gone... Would official ROM fix this?
3: Which features do we have in stock rom that are not present on CM?
4: On stock rom, can you Root/Unroot and then re-lock the phone as if nothing happened? ¿Do you lose data if you do so?
5: There is a lot of confusion about this: When you unlock the phone, the disclaimer says that process "MIGHT" VOID THE WARRANTY..... does it void it or not?, what does that "might" mean?
Overall, the phone is wonderful and I'm really happy, I'm just thinking about testing stock rom but I don't want to lose functionality...
I'm waiting for your advice.
Thanks!!
Click to expand...
Click to collapse
Thread allready excists:
https://www.google.nl/url?sa=t&rct=...O-GpCSO_eYYCvy4ortY3ZoQ&bvm=bv.44158598,d.d2k
There are tons of these threads, no need to post yet another one and don`t wait on other users yo answer YOUR question. Google and search XDA please.
After seeing that your machine is suffering from not grasp the port, we have decided to make you a gift.
And so, we present you MIUI7, based on Android 5.1.1
To tell what Miui, probably does not make sense. All know very well that it is)
Miui extreme version, based on the Russification of our friends from Multirom.
Enough many bukf and start.
What we need to install the firmware.
1. It is necessary to make a patch for the normal memory map. (I did so, because the drain that was just adstoy) Link to the instructions.
2. Download the ported recovery ...
and install it.
3. Downloading firmware itself ...
4. After installation, be sure to do all wipes are! Well, rejoice firmware.
But it may not be doing so well. There are certainly bugs.
1. Does not work illumination ring, but I suggested that it can be run using Xposed
Also, the bottom buttons do not work off the vibration.
2. Failure to display the internal memory and the processor (I think in the future to fix that)
Team ...
Mod edit: Thread closed! DL links no longer working and removed.
does this work for blade s6 plus??
how about blade v6?
Hello!
Is point 1 really necessary - wasting some memory space would not be a real problem for me.
What do you mean with 'adstoy'?
Best regards.
I've tried posting this in MIUI forums and haven't gotten any replies. I'll try my luck with XDA.
How do you correctly identify Redmi 2?
I've got a RM2 that has the 2014811 variant when I check it onscreen.. But I'm skeptic that it's correct. All I know is 2014811 is suppose to be a normal Redmi 2 with 1 gigs of RAM and 8 gigs of ROM. But mine's a 2 gigs RAM & 16 gigs ROM. If I'm correct, with specs like those, my RM2 is suppose to be a RM2 enchanced variant (Pro, Prime, etc). What I can't figure out is which variant is it that I'm dealing with. Another thing that I know is that the RM2 version of mine isn't the global one because I didn't buy it from an official shop, I bought it from an external distributor. The RM 2 box is written in chinese and the characters underneath the battery are full chinese (except for the S/N and IMEI). Is my RM 2 a 2014818 or 2014819? How can I find out which variant is it that I have with me.
Thank you.
2014819- Brazilian variants
2014818- Redmi 2 prime variation of 2014811
ezrawk said:
I've tried posting this in MIUI forums and haven't gotten any replies. I'll try my luck with XDA.
How do you correctly identify Redmi 2?
I've got a RM2 that has the 2014811 variant when I check it onscreen.. But I'm skeptic that it's correct. All I know is 2014811 is suppose to be a normal Redmi 2 with 1 gigs of RAM and 8 gigs of ROM. But mine's a 2 gigs RAM & 16 gigs ROM. If I'm correct, with specs like those, my RM2 is suppose to be a RM2 enchanced variant (Pro, Prime, etc). What I can't figure out is which variant is it that I'm dealing with. Another thing that I know is that the RM2 version of mine isn't the global one because I didn't buy it from an official shop, I bought it from an external distributor. The RM 2 box is written in chinese and the characters underneath the battery are full chinese (except for the S/N and IMEI). Is my RM 2 a 2014818 or 2014819? How can I find out which variant is it that I have with me.
Thank you.
Click to expand...
Click to collapse
for me device name is beneath the battery.
hopefully for you also it must be given.remove back cover and check.
wt88047 - 2014811/12/17/18/19/21
wt86047 - 2014813/816/2014112
TecnoTailsPlays said:
2014819- Brazilian variants
2014818- Redmi 2 prime variation of 2014811
Click to expand...
Click to collapse
sarath67 said:
for me device name is beneath the battery.
hopefully for you also it must be given.remove back cover and check.
Click to expand...
Click to collapse
raymond_bqg said:
wt88047 - 2014811/12/17/18/19/21
wt86047 - 2014813/816/2014112
Click to expand...
Click to collapse
Guys thanks for your replies. After intensive research, I have concluded that: yes, my device is totally a WT88047 - HM201411 - HM 2 LTE-CU (China Unicom) variant. But now I've found out something else that's got me hooked up on finding out. I'm using latest stable stock rom (MIUI 8 - 8.2.1.0), and I checked out my Mi-Account menu in settings, snooped down to devices and... My RM2P is named Redmi 2W..... So... What the heck is Redmi 2W? I've been searching here and there with no luck on finding out what a Redmi 2W is (Haven't checked the chinese sites though). Does anyone know what it is?
ezrawk said:
Guys thanks for your replies. After intensive research, I have concluded that: yes, my device is totally a WT88047 - HM201411 - HM 2 LTE-CU (China Unicom) variant. But now I've found out something else that's got me hooked up on finding out. I'm using latest stable stock rom (MIUI 8 - 8.2.1.0), and I checked out my Mi-Account menu in settings, snooped down to devices and... My RM2P is named Redmi 2W..... So... What the heck is Redmi 2W? I've been searching here and there with no luck on finding out what a Redmi 2W is (Haven't checked the chinese sites though). Does anyone know what it is?
Click to expand...
Click to collapse
what's your purpose, flashing custom roms? simply flash twrp for wt88047 and flash whichever rom you want
ezrawk said:
Guys thanks for your replies. After intensive research, I have concluded that: yes, my device is totally a WT88047 - HM201411 - HM 2 LTE-CU (China Unicom) variant. But now I've found out something else that's got me hooked up on finding out. I'm using latest stable stock rom (MIUI 8 - 8.2.1.0), and I checked out my Mi-Account menu in settings, snooped down to devices and... My RM2P is named Redmi 2W..... So... What the heck is Redmi 2W? I've been searching here and there with no luck on finding out what a Redmi 2W is (Haven't checked the chinese sites though). Does anyone know what it is?
Click to expand...
Click to collapse
shyampandey said:
what's your purpose, flashing custom roms? simply flash twrp for wt88047 and flash whichever rom you want
Click to expand...
Click to collapse
Just take a backup your current ROM by t.w.r.p before flashing ROM(if something goes wrong).
shyampandey said:
what's your purpose, flashing custom roms? simply flash twrp for wt88047 and flash whichever rom you want
Click to expand...
Click to collapse
I've got: touchscreen issues, wake up issues, twrp issues, kernel issues and proximity issues. I'm guessing even if I tell you what I'm experiencing, you won't be able to find a solution for it (please don't say I've got defective hardware, because I don't. Why? Because 3 of my friends bought the same device as mine, in the same online shop and all of them have the same issues). But even so I'll just post all of em and cross my fingers:
TWRP's bugged, needs to timeout (screen off) first before I'm able to responsively use it (touchscreen bugged, tried all latest TWRP versions, including kumajaya's old twrp builds. Touchscreen does work on several 2.8.7.0 and below versions for KK bootloader).
Any custom rom I've flashed will always face lockscreen issues (waking up device using power button leads to unresponsive and un-swipe-able touchscreen, that means I can't unlock my device, seems like it has to do with with proximity too, and please don't ask me about gestures and modified navigation buttons, because I don't use them at all: dt2w, s2w, etc).
Any custom kernel used will always lead to device not being able to wake up (pressing power button doesn't wake up the screen, stays black, have to reset device by force, still happens even though I'm using stock CPU govs *interactive* and I/O scheds *noop* not using hotplugs, doesn't change anything)
I still even face all those problems in Stock MIUI (KK or LP.. 7, 8)
Try downloading china developer ROM? Yeah. I've done that.. Even went to the Chinese download page of miui to download the exact recommended MIUI 8 C-Dev ROM for my HM 2 LTE-CU variant, and still the same bugs occur.
Xposed? I've experimented using stock and custom roms (below API 24) that are Un-Xposed. They still exhibit the same problems as above.
Clean flash dirty flash? I totally understand what those are.
Wipe dalvik cache and cache.. Don't even dare ask about those.
Fix Permissions? Yeah.. It didnt make a difference..
Post dmseg and logcats? Trust me, you devs will probably mark my device as a different type of WT8847 (and by saying that means even if you succeed to find the problems, to fix them means you gotta totally change the 'insides' of roms and stuff to make it compatible with mine. It'll probably be a waste of time if I post those 2 guys here.
Can you help me, bro?
raymond_bqg said:
Just take a backup your current ROM by t.w.r.p before flashing ROM(if something goes wrong).
Click to expand...
Click to collapse
Yeah, I know where you're getting at bro. Let me ask you this, does it not annoy you to death when you're restoring the same backup ROMs frequently just because suddenly your device can't use wi-fi (bugged) or tether, or maybe one of the issues above occur and you just gotta try your best to keep it 'clean'.. again.. and again.. and again? I just need a damn good daily driver without issues for crying out loud :cyclops:
ezrawk said:
I've got: touchscreen issues, wake up issues, twrp issues, kernel issues and proximity issues. I'm guessing even if I tell you what I'm experiencing, you won't be able to find a solution for it (please don't say I've got defective hardware, because I don't. Why? Because 3 of my friends bought the same device as mine, in the same online shop and all of them have the same issues). But even so I'll just post all of em and cross my fingers:
TWRP's bugged, needs to timeout (screen off) first before I'm able to responsively use it (touchscreen bugged, tried all latest TWRP versions, including kumajaya's old twrp builds. Touchscreen does work on several 2.8.7.0 and below versions for KK bootloader).
Any custom rom I've flashed will always face lockscreen issues (waking up device using power button leads to unresponsive and un-swipe-able touchscreen, that means I can't unlock my device, seems like it has to do with with proximity too, and please don't ask me about gestures and modified navigation buttons, because I don't use them at all: dt2w, s2w, etc).
Any custom kernel used will always lead to device not being able to wake up (pressing power button doesn't wake up the screen, stays black, have to reset device by force, still happens even though I'm using stock CPU govs *interactive* and I/O scheds *noop* not using hotplugs, doesn't change anything)
I still even face all those problems in Stock MIUI (KK or LP.. 7, 8)
Try downloading china developer ROM? Yeah. I've done that.. Even went to the Chinese download page of miui to download the exact recommended MIUI 8 C-Dev ROM for my HM 2 LTE-CU variant, and still the same bugs occur.
Xposed? I've experimented using stock and custom roms (below API 24) that are Un-Xposed. They still exhibit the same problems as above.
Clean flash dirty flash? I totally understand what those are.
Wipe dalvik cache and cache.. Don't even dare ask about those.
Fix Permissions? Yeah.. It didnt make a difference..
Post dmseg and logcats? Trust me, you devs will probably mark my device as a different type of WT8847 (and by saying that means even if you succeed to find the problems, to fix them means you gotta totally change the 'insides' of roms and stuff to make it compatible with mine. It'll probably be a waste of time if I post those 2 guys here.
Can you help me, bro?
Yeah, I know where you're getting at bro. Let me ask you this, does it not annoy you to death when you're restoring the same backup ROMs frequently just because suddenly your device can't use wi-fi (bugged) or tether, or maybe one of the issues above occur and you just gotta try your best to keep it 'clean'.. again.. and again.. and again? I just need a damn good daily driver without issues for crying out loud :cyclops:
Click to expand...
Click to collapse
that's all are happening 'cause of source code modification of lineage from cyanogen which caused your device unfavorable base code modification, only thing can be done is flash stock rom, bootloader, recovery, modem, everything using fastboot.
shyampandey said:
that's all are happening 'cause of source code modification of lineage from cyanogen which caused your device unfavorable base code modification, only thing can be done is flash stock rom, bootloader, recovery, modem, everything using fastboot.
Click to expand...
Click to collapse
So in other words "bye-bye" to custom roms right? I'm in latest stable global miui 8 btw (LP), I clean flashed it via download mode, those problems still show up though. Okay let me just try to flash miui via fastboot or download mode again.
ezrawk said:
So in other words "bye-bye" to custom roms right? I'm in latest stable global miui 8 btw (LP), I clean flashed it via download mode, those problems still show up though. Okay let me just try to flash miui via fastboot or download mode again.
Click to expand...
Click to collapse
yeah, after problem bring fixed completely, you can come back to custom roms.
Hi,
My M30s started randomly restarting after a software update. I could not find solutions here when I searched but it appears a lot of people on the internet having been facing similar issues for quite a few months now. The Samsung community forums are full of multiple messages and Samsung is pushing people to get to their phones to the service centers and are getting the motherboards replaced for free if the warranty is valid (or at a cost of INR 9,000 otherwise).
In any case, I found another poster on the Samsung forums who seems much more tech savvy than I am. And he seems to have solved the problem on his phone by changing 2 lines of code in the Linux kernel wand rebuilding the OS afterward.
Like I said, I am not tech savvy enough for this, but I thought I would post the link here because I could not find this particular fix here.
Re: READ THIS IF YOUR SAMSUNG GALAXY M30S KEEPS RANDOMLY FREEZING AND RESTARTING AUTOMATICALLY
To add a bit of my research into this problem: My phone (SM-M307FN) is rebooting many times every single day due to a Linux kernel issue which has been already fixed a long time ago in the mainline version. I am still running Android 10, because that's the latest version (M307FNXXU2BTC6) of the...
r2.community.samsung.com
(Here is the text from the post in case you are not able to open it)
-----------------------------------------------------------------------
To add a bit of my research into this problem:
My phone (SM-M307FN) is rebooting many times every single day due to a Linux kernel issue which has been already fixed a long time ago in the mainline version. I am still running Android 10, because that's the latest version (M307FNXXU2BTC6) of the OS Samsung has released on their open-source portal. I can use this source code to fix and rebuild the OS to prevent the issue from happening.
The issue and the fix is well known among the Samsung M30s community. It's two lines of code that need to be changed to prevent at least one of the common reasons for frequent reboots.
It takes a lot of work for a private user to fix those two lines of code, because Samsung releases source code that's non-trivial to compile and actually run on your device afterwards.
Samsung's Android 11 still ships with the same old kernel version (4.14.62) as their Android 9 (4.14.62), released back in 2018. There might have been some fixes between 4.14.62-19694174 and 4.14.62-20748039 introduced by Samsung in the meantime.
Regardless, this fix is not part of the source code for M307FNXXU2BTC6 (linked above) that's been released by Samsung in June 2020. Therefore, it doesn't seem like Samsung is actually applying all fixes to their kernels.
The kernel itself should have been upgraded to a higher version - at least to 4.19 - to fix bugs that's been plaguing users of Exynos 9611 chips running on Linux v4.14 for a long time.
Samsung: Please apply this fix to your Android kernels and push the update to your customers. Thank you!
References about the "fix NULL pointer deref in smaps_pte_range()":
Mainline Linux kernel fix:
[4.19,248/361] mm: /proc/pid/smaps_rollup: fix NULL pointer deref in smaps_pte_range()
https://lore.kernel.org/patchwork/patch/1010971/
Google Android Linux kernel backported this change in 2019 :
https://android.googlesource.com/kernel/common/+/043c92bd0517e0018cb6307390eb9c36b864fb9f
--------------------------------------------------------------------------------------
EDIT: After more hours of experimenting I have managed to compile a kernel with the patch mentioned in this post. I can confirm that I faced no reboots since I flashed my phone with this new kernel. Hence, I can confirm this fix really prevents frequent reboots.
superstarksa said:
Hi,
My M30s started randomly restarting after a software update. I could not find solutions here when I searched but it appears a lot of people on the internet having been facing similar issues for quite a few months now. The Samsung community forums are full of multiple messages and Samsung is pushing people to get to their phones to the service centers and are getting the motherboards replaced for free if the warranty is valid (or at a cost of INR 9,000 otherwise).
In any case, I found another poster on the Samsung forums who seems much more tech savvy than I am. And he seems to have solved the problem on his phone by changing 2 lines of code in the Linux kernel wand rebuilding the OS afterward.
Like I said, I am not tech savvy enough for this, but I thought I would post the link here because I could not find this particular fix here.
Re: READ THIS IF YOUR SAMSUNG GALAXY M30S KEEPS RANDOMLY FREEZING AND RESTARTING AUTOMATICALLY
To add a bit of my research into this problem: My phone (SM-M307FN) is rebooting many times every single day due to a Linux kernel issue which has been already fixed a long time ago in the mainline version. I am still running Android 10, because that's the latest version (M307FNXXU2BTC6) of the...
r2.community.samsung.com
(Here is the text from the post in case you are not able to open it)
-----------------------------------------------------------------------
To add a bit of my research into this problem:
My phone (SM-M307FN) is rebooting many times every single day due to a Linux kernel issue which has been already fixed a long time ago in the mainline version. I am still running Android 10, because that's the latest version (M307FNXXU2BTC6) of the OS Samsung has released on their open-source portal. I can use this source code to fix and rebuild the OS to prevent the issue from happening.
The issue and the fix is well known among the Samsung M30s community. It's two lines of code that need to be changed to prevent at least one of the common reasons for frequent reboots.
It takes a lot of work for a private user to fix those two lines of code, because Samsung releases source code that's non-trivial to compile and actually run on your device afterwards.
Samsung's Android 11 still ships with the same old kernel version (4.14.62) as their Android 9 (4.14.62), released back in 2018. There might have been some fixes between 4.14.62-19694174 and 4.14.62-20748039 introduced by Samsung in the meantime.
Regardless, this fix is not part of the source code for M307FNXXU2BTC6 (linked above) that's been released by Samsung in June 2020. Therefore, it doesn't seem like Samsung is actually applying all fixes to their kernels.
The kernel itself should have been upgraded to a higher version - at least to 4.19 - to fix bugs that's been plaguing users of Exynos 9611 chips running on Linux v4.14 for a long time.
Samsung: Please apply this fix to your Android kernels and push the update to your customers. Thank you!
References about the "fix NULL pointer deref in smaps_pte_range()":
Mainline Linux kernel fix:
[4.19,248/361] mm: /proc/pid/smaps_rollup: fix NULL pointer deref in smaps_pte_range()
https://lore.kernel.org/patchwork/patch/1010971/
Google Android Linux kernel backported this change in 2019 :
https://android.googlesource.com/kernel/common/+/043c92bd0517e0018cb6307390eb9c36b864fb9f
--------------------------------------------------------------------------------------
EDIT: After more hours of experimenting I have managed to compile a kernel with the patch mentioned in this post. I can confirm that I faced no reboots since I flashed my phone with this new kernel. Hence, I can confirm this fix really prevents frequent reboots.
Click to expand...
Click to collapse
Amazing work brother, everyone is facing this restart problem but you can help
Can you compile the latest kernal(4.14.113) and share it with our M30s community.
razs.originals said:
Amazing work brother, everyone is facing this restart problem but you can help
Can you compile the latest kernal(4.14.113) and share it with our M30s community.
Click to expand...
Click to collapse
Like I said in my post, I am not tech savvy enough to do this. And I am wondering if this problem has been widely reported even. This is the place I expected to find lot of buzz but i dont see any
Everyone is upset with this Samsung's reboot problem. Anyways we users will find a solution.
I am a M30s owner. I have done this on my phone and it's a temporary fix. Atleast try this and wait for the official fix. It's better to have something than nothing.
How To Fix Restart Issue On Galaxy M30s, M31, M31s, A50, A50s? (Updated) - SamsungSFour.Com
How To Fix Restart Issue On Galaxy M30s, M31, M31s, A50, A50s? (Latest Method)
www.samsungsfour.com