@Capsia Okay, based off of that, it seems like I am not in the terminal, unfortunately. Is there anything else I could try?

@joe The permissions were -rwxrwxrwx 1 root root, but that should work as well (albeit it could be more secure). The profile has the same name as the SSID.

After testing, I don't think I was in the terminal. Should I try reinstalling UBPorts from scratch, and is there an initial setup page that I haven't bypassed that I may be hitting? I'm trying to figure out why I didn't access the terminal. I believe I followed the instructions exactly.

@joe I tried copying the file from my Manjaro machine, replacing the permissions and adding the password, but it didn't seem to work, as I couldn't detect my phone on nmap from another computer on the LAN. I even tried to get into the terminal to use nmcli to connect (https://docs.ubuntu.com/core/en/stacks/network/network-manager/docs/configure-wifi-connections) but it didn't seem to work, either. How can i get my internet connected, and is there any way to verify I'm actually in the terminal? Sorry for how complicated this is getting, and thanks for the help.

@joe Okay, I think nearly everything is setup for SSH. The one thing I can confirm isn't working yet is wifi. My network runs on wpa-psk, and I need some way to bring the credentials to the phone. Is this possible through adb shell?

EDIT: Also, do I need to TAB when opening the terminal before entering my password? Thanks.

@doniks
Ah, I didn't add sbin, /usr/bin, and /usr/sbin to PATH. passwd was in /usr/bin. I changed the password, so I think I'm able to get in. But, it seems like adb isn't even supported on the OP3T, so it seems like a moot point. @joe since you were able to help me navigate to developer mode, do you think you can tell me how to open the terminal with a keyboard, so I could try to setup SSH?

@doniks
ls -l /system

total 88
drwxr-xr-x   2 root root 4096 2020-06-26 06:53 android
drwxr-xr-x   2 root root 4096 2017-01-10 21:46 bin
drwxr-xr-x   2 root root 4096 2016-04-12 20:14 boot
lrwxrwxrwx   1 root root   14 2020-06-26 06:53 cache -> /android/cache
lrwxrwxrwx   1 root root   13 2020-06-26 06:53 data -> /android/data
drwxr-xr-x   3 root root 4096 2020-06-26 05:28 debian
drwxr-xr-x   4 root root 4096 2020-06-26 05:24 dev
drwxr-xr-x 110 root root 4096 1973-06-18 14:58 etc
lrwxrwxrwx   1 root root   16 2020-06-26 06:53 factory -> /android/factory
lrwxrwxrwx   1 root root   17 2020-06-26 06:53 firmware -> /android/firmware
drwxr-xr-x   3 root root 4096 2020-06-26 05:32 home
drwxr-xr-x  19 root root 4096 2020-06-26 05:28 lib
drwx------   2 root root 4096 1970-01-01 00:00 lost+found
drwxr-xr-x   2 root root 4096 2020-06-26 05:23 media
drwxr-xr-x   2 root root 4096 2020-06-26 05:23 mnt
lrwxrwxrwx   1 root root   12 2020-06-26 06:53 odm -> /android/odm
drwxr-xr-x   3 root root 4096 2020-06-26 05:31 opt
lrwxrwxrwx   1 root root   16 2020-06-26 06:53 persist -> /android/persist
drwxr-xr-x   2 root root 4096 2016-04-12 20:14 proc
drwx------   2 root root 4096 2020-06-26 05:32 root
drwxr-xr-x   8 root root 4096 2020-06-26 05:31 run
drwxr-xr-x   2 root root 4096 2020-06-26 05:32 sbin
drwxr-xr-x   2 root root 4096 2020-06-26 05:23 srv
drwxr-xr-x   2 root root 4096 2016-02-05 09:48 sys
lrwxrwxrwx   1 root root   15 2020-06-26 06:53 system -> /android/system
drwxrwxrwt   2 root root 4096 2020-06-26 05:32 tmp
drwxr-xr-x   2 root root 4096 2020-06-26 06:53 userdata
drwxr-xr-x  10 root root 4096 2020-06-26 05:23 usr
drwxr-xr-x  11 109  113  4096 2020-06-25 12:57 var
lrwxrwxrwx   1 root root   22 2020-06-26 06:53 vendor -> /android/system/vendor

Should I reinstall UBPorts?

@doniks Okay, I'll try it out. The PATH thing was a typo on my part; I did PATH=$PATH:/bin, but it seems like I didn't have the right idea from the start, so I'll try your instructions. Thanks

Edit:
ls -l /

total 3372
dr-xr-xr-x   4 root root         0 1970-01-04 02:12 acct
lrwxrwxrwx   1 root root        11 1970-01-01 00:00 bin -> /system/bin
lrwxrwxrwx   1 root root        50 1970-01-01 00:00 bugreports -> /data/user_de/0/com.android.shell/files/bugreports
drwxr-xr-x   3 root root        60 2017-01-12 13:56 cache
lrwxrwxrwx   1 root root        13 1970-01-01 00:00 charger -> /sbin/charger
dr-xr-xr-x   2 root root        40 1970-01-01 00:00 config
lrwxrwxrwx   1 root root        17 1970-01-01 00:00 d -> /sys/kernel/debug
drwxr-xr-x   8 root root      4096 2017-01-09 11:51 data
lrwxrwxrwx   1 root root        12 1970-01-01 00:00 default.prop -> prop.default
drwxr-xr-x  10 root root      3760 1970-01-04 02:12 dev
drwxr-xr-x   2 root root       140 2017-01-12 13:56 etc
-rw-r--r--   1 root root     33643 1970-01-01 00:00 file_contexts
-rw-r--r--   1 root root    674825 1970-01-01 00:00 file_contexts.bin
-rwxr-x---   1 root root   2212400 1970-01-01 00:00 init
-rwxr-x---   1 root root      3114 1970-01-01 00:00 init.rc
-rwxr-x---   1 root root       103 1970-01-01 00:00 init.recovery.hlthchrg.rc
-rwxr-x---   1 root root        52 1970-01-01 00:00 init.recovery.ldconfig.rc
-rwxr-x---   1 root root        35 1970-01-01 00:00 init.recovery.mksh.rc
-rwxr-x---   1 root root      5727 1970-01-01 00:00 init.recovery.qcom.rc
-rwxr-x---   1 root root       111 1970-01-01 00:00 init.recovery.service.rc
-rwxr-x---   1 root root      1323 1970-01-01 00:00 init.recovery.usb.rc
drwxr-xr-x   3 root root        60 1970-01-01 00:00 license
drwxr-xr-x   3 root system      60 1970-01-04 02:12 mnt
drwxr-xr-x   2 root root       200 1970-01-01 00:00 odm
drwxr-xr-x   2 root root        40 1970-01-01 00:00 oem
drwxrwxrwx   2 root root        40 1970-01-04 02:12 persist
-rw-r--r--   1 root root     23786 1970-01-01 00:00 plat_file_contexts
-rw-r--r--   1 root root      7212 1970-01-01 00:00 plat_hwservice_contexts
-rw-r--r--   1 root root      6687 1970-01-01 00:00 plat_property_contexts
-rw-r--r--   1 root root      1315 1970-01-01 00:00 plat_seapp_contexts
-rw-r--r--   1 root root     14057 1970-01-01 00:00 plat_service_contexts
dr-xr-xr-x 384 root root         0 1970-01-01 00:00 proc
lrwxrwxrwx   1 root root        15 1970-01-01 00:00 product -> /system/product
-rw-r--r--   1 root root      3042 1970-01-01 00:00 prop.default
drwxr-xr-x   3 root root        80 1970-01-01 00:00 res
drwx------   2 root root        40 2019-04-15 10:55 root
drwxr-x---   2 root root      6700 2017-01-12 13:59 sbin
drwxrwx---   3 root root      4096 2017-01-09 11:51 sdcard
-rw-r--r--   1 root root    387957 1970-01-01 00:00 sepolicy
drwxr-xr-x   2 root root        40 1970-01-04 02:12 sideload
drwxr-x--x   2 root root        40 1970-01-01 00:00 storage
dr-xr-xr-x  12 root root         0 1970-01-04 02:12 sys
drwxr-xr-x  24 109  113       4096 2017-01-10 21:47 system
drwxrwxr-x   2 root shell       80 2017-01-12 14:01 tmp
drwxr-xr-x   5 root root       180 1970-01-01 00:00 twres
-rw-r--r--   1 root root      5272 1970-01-01 00:00 ueventd.rc
drwxrwxrwx   2 root root        40 2017-01-12 13:56 usb_otg
drwxr-xr-x   3 root root        60 1970-01-01 00:00 vendor
-rw-r--r--   1 root root      6178 1970-01-01 00:00 vendor_file_contexts
-rw-r--r--   1 root root         0 1970-01-01 00:00 vendor_hwservice_contexts
-rw-r--r--   1 root root       218 1970-01-01 00:00 vendor_property_contexts
-rw-r--r--   1 root root         0 1970-01-01 00:00 vendor_seapp_contexts
-rw-r--r--   1 root root         0 1970-01-01 00:00 vendor_service_contexts
-rw-r--r--   1 root root        65 1970-01-01 00:00 vndservice_contexts

cat /etc/fstab

/dev/block/sda3 /cache ext4 rw 0 0
/dev/block/sda15 /data ext4 rw 0 0
/dev/block/sda2 /persist ext4 rw 0 0
/dev/block/sde20 /system ext4 rw 0 0
 /usb_otg vfat rw 0 0

mount

'rootfs on / type rootfs (rw,seclabel,size=2834740k,nr_inodes=708685)
tmpfs on /dev type tmpfs (rw,seclabel,nosuid,relatime,size=2918948k,nr_inodes=729737,mode=755)
devpts on /dev/pts type devpts (rw,seclabel,relatime,mode=600)
proc on /proc type proc (rw,relatime,gid=3009,hidepid=2)
sysfs on /sys type sysfs (rw,seclabel,relatime)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
tmpfs on /mnt type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime,size=2918948k,nr_inodes=729737,mode=755,gid=1000)
none on /acct type cgroup (rw,relatime,cpuacct)
tmpfs on /tmp type tmpfs (rw,seclabel,relatime,size=2918948k,nr_inodes=729737)
pstore on /sys/fs/pstore type pstore (rw,seclabel,relatime)
adb on /dev/usb-ffs/adb type functionfs (rw,relatime)
/dev/block/sda15 on /data type ext4 (rw,seclabel,relatime,data=ordered)
/dev/block/sda15 on /sdcard type ext4 (rw,seclabel,relatime,data=ordered)
/dev/block/sde20 on /system type ext4 (rw,seclabel,relatime,data=ordered)

mount /data

mount: '/dev/block/sda15'->'/data': Device or resource busy

ls -l /data

1|OnePlus3:/ # ls -l /data
total 32792
-rw-------  1 root   root   33554432 1973-06-18 14:57 SWAP.img
drwxrwx--x 44 system system     4096 1973-06-18 14:58 android-data
drwxr-xr-x  3 root   root       4096 1973-06-18 14:57 cache
drwx------  2 root   root       4096 1970-01-01 00:02 lost+found
drwxrwx---  3 root   root       4096 2017-01-09 11:51 media
drwxr-xr-x  5 root   root       4096 1973-06-18 14:58 system-data
drwxr-xr-x  3 root   root       4096 2020-06-26 05:32 user-data

The first step of the guide you linked involves the following the command: mount /data/rootfs.img /a, which outputs that rootfs.img does not exist.

@doniks I booted into TWRP. Opened up the adb shell and did the following:

twrp mount system
chroot system
PATH=$PATH:PATH
passwd phablet

And I got /bin/sh: 3: passwd: not found

Since it doesn't seem like I'll set up adb or ssh, any suggestions to run headlessly on my phone? Thanks.

I've tried all of the suggestions so far. I don't know if a password is on my default, and 0000 didn't work (also is there an initial setup I have to complete before being able to perform this action). I chrooted in TWRP, but passwd was not in the /system/bin directory. So, I'm making progress, but am not there yet.

@joe Thank you so much. The only thing is that I don't have a password, which is supposedly required for enabling the mode. Also, how would I accept my computer's keys for adb? Sorry for all of the complications.

@joe Thanks for the help. After flashing TWRP, I got my home wi-fi profile onto the phone (the one on my PC had a .nmconnection extension, so I kept that).

In order to turn on SSH, it seems, I need to do some stuff in the terminal on the phone, or through adb. ADB can be enabled from Settings - About - Developer Mode - check the box to turn it on according to this: http://docs.ubports.com/en/latest/userguide/advanceduse/adb.html Could I get help with that, possibly? Like I said previously, I could navigate with a keyboard, but I'll need help with that. Thanks again.

After breaking the screen on my OnePlus 3T, I wanted to use it as a Syncthing device as well as just a basic Linux server. I decided that Ubuntu Touch with adb would work for this (and that from there it should be simple to setup the network and ssh and all that). So far, I've successfully installed Ubuntu Touch.

Since the screen is completely broken (no touchscreen, nothing displays on the screen), I was wondering how I could enable developer mode. I have a USB keyboard and USB-OTG adapter I could use to control the phone with a keyboard. I just need guidance on what keypresses to use to get me to the right spot.

What sequence would I use to navigate and enable the option? Are there other sequences I must use if there's a first-time setup screen?

Thanks.

EDIT: also how would i set up a password in order to enable developer mode?