[AT&T HTC One (M9)] clsA:
Update 12/23/2015 >> See my signature below for Android M

Thanks to @Jonny We now have the AT&T RUU

M9_ATT_Cingular_US_1.32.502.9

https://www.androidfilehost.com/?fid=95916177934556955

modelid: 0PJA11000
cidnum: CWS__001
mainver: 1.32.502.9

~Update~ Now the New Official Android Lollipop 5.1 RUU.exe is out for AT&T 2.11.502.18

http://www.htc.com/us/support/htc-one-m9-att/news/

~Update~10-26-15

Thanks [MENTION=4539861]krazyace35[/MENTION] - This is the rom.zip pulled from the 2.11.502.18 RUU >>

https://www.androidfilehost.com/?fid=24052804347847327 or http://1drv.ms/1kIro4b

and the Full RUU.exe is here >>

http://dl3.htc.com.s3.amazonaws.com...51_SENSE70_ATT_MR_Cingular_US_2.11.502.18.exe

Thanks to [MENTION=4539861]krazyace35[/MENTION] the 2.6.502.18 OTA and stock recovery are posted here >> http://xdaforums.com/att-one-m9/general/2-6-502-18-ota-t3187078

and the older 1.32.502.31 is here

http://dl3.htc.com/application/RUU_...21_62.05.50320G_F_release_426950_signed_2.exe

I have pulled the Rom.zip from the 1.32.502.31 RUU for you it's here >> https://www.androidfilehost.com/?fid=96042739161891969

flash with htc_fastboot >> https://www.androidfilehost.com/?fid=96042739161891970

modelid: 0PJA11000
cidnum: CWS__001
mainver: 1.32.502.31
aareport:1
btype:1

And thanks To @jcase we now have S-OFF

SunShine S-Off v3.1 for the HTC One M9

http://theroot.ninja/

With S-OFF we can now convert the AT&T phones to Developer Edition

The Developer Edition does not have any of the AT&T Bloatware in it and the phone are the same hardware

all that's needed is a simple CID change and flash the Developer Edition RUU.

You could also convert to International but it will require a MID change that I'll post here ...

Great news @scotty1223 has posted the simple way to change your MID

So to convert your Mid to International WWE the command would be

fastboot oem writemid 0PJA10000

and to AT&T / Developer Edition would be

fastboot oem writemid 0PJA11000

To convert to Developer Edition, you phone will need to be unlocked at htcdev.com with TWRP 2.8.6.4 Beta Flashed in Download mode (Black bootloader screen) Please read this before flashing TWRP And Rooted with SuperSU Flashed in TWRP.

Once your unlocked and Rooted and S-OFF you can change your CID to the Developer Edition

All fastboot commands will take place in Download Mode / not in the normal white bootloader screen

fastboot oem writecid BS_US001

or

fastboot oem writecid BS_US002

followed by fastboot reboot-bootloader

Both will work for flashing the RUU.

For Super CID use

fastboot oem writecid 11111111

fastboot reboot-bootloader

At this point your ready to backup all your stuff and flash the Developer Edition RUU

I advise you copy the entire internal sdcard of the phone to your PC before flashing the RUU

also use google / and HTC backup to save your phones contacts, app's and SMS, Call history ..etc

Here are the Developer Edition RUU's we have so far (to flash these please rename them to RUU.zip to simplify the commands)

modelid: 0PJA11000
cidnum: BS_US001
cidnum: BS_US002

This is the one the phone shipped with ( this should receive an OTA update as soon as you flash it)

0PJAIMG_HIMA_UL_L50_SENSE70_ATT_NA_Gen_Unlock_1.32.617.6_R2_Radio_01.01_U11440221_59.04.50303G_2_F_release_426167_signed.zip

and this is the 2nd Software / with Camera, overheating Fix (use this one)

0PJAIMG_HIMA_UL_L50_SENSE70_ATT_NA_Gen_Unlock_1.32.617.30_Radio_01.01_U11440221_62.05.50320G_F_release_427069_signed.zip

Also here's the Android Lollipop 5.1 - 2.11.617.15 RUU.EXE direct from HTC >> http://www.htc.com/us/support/htc-one-m9/news/

And the Rom.zip pulled from the RUU >> https://www.androidfilehost.com/?fid=24052804347772812

New 8/30/15 - Developer Edition RUU 2.11.617.15 RUU_HIMA_UL_L51_SENSE70_ATT_MR_NA_Gen_Unlock_2.11.617.15_Radio_01.01_U11440601_76.03.50611G_F_release_445910_signed_2.Rom.zip

M9_stock-system_2.11.617.15_TWRP_nandroid.rar >> Thanks [MENTION=2605798]nkk71[/MENTION]

And here's the OTA >> OTA_HIMA_UL_L51_SENSE70_ATT_MR_NA_Gen_Unlock_2.11.617.15-2.8.617.4_release_445912.zip

If you have problems with the normal fastboot flashing any RUU you'll have to use the htc_fastboot pulled from the RUU.EXE

you can download it here >> https://www.androidfilehost.com/?fid=96039337900114016 >> Thanks go to @Sneakyghost for sharing

Note their is a newer htc_fastboot here >> https://www.androidfilehost.com/?fid=24052804347775783 that seems to fix the old one only flashing the first 300mb of the system.img

htc_fastboot oem rebootRUU

htc_fastboot flash zip RUU.zip

htc_fastboot flash zip RUU.zip <this may not be needed it might restart on it's own>

htc_fastboot reboot

You can also use the 0PJAIMG.ZIP method

rename the RUU.zip to 0PJAIMG.ZIP, place it on a ext sd card formatted in FAT32 (a 16 or 32gig one should work), reboot into DOWNLOAD_MODE, agree and it should flash.

If you need to go back to AT&T software just change your CID back to CWS__001 and Flash the AT&T RUU and you'll be back to Stock

I'll post more later on going back to complete stock.

Some other useful files

Recovery flashable Radios here >> https://www.androidfilehost.com/?w=files&flid=32827

Developer Edition Stock Recovery's

Developer Edition 1.32.617.30 Firmware without red text

1.32.502.9_Stock_recovery_signed.img

1.32.502.9_radio.img

ATT_HIMA_1.32.502.31.Stock.recovery_signed.img

ATT_HIMA_1.32.502.31.radio.img

fastboot-mac.zip