Gaining ADB Access on a Mobiwire Sakari
Last year a technology retailer here in New Zealand, PB Tech, was running a Black Friday sale, and I came across their deal for a Vodafone Smart A9 - a rebranded Mobiwire Sakari "feature phone" - for NZ$13. I had previously encountered the phone a few more weeks before this at a display stand in a Harvey Norman store, and from briefly messing around with it, I realised it was running a really pruned back older version of Android. I figured at the time that I might as well buy one and see what I could get it to do.
The Sakari is a simple phone - it has a 240x320 TFT LCD screen, a VGA camera with flash, a 3x4 physical keyboard and 5-way navigator keypad, a 3.5mm headset jack, a microUSB connector, a micro SIM slot and a microSD slot. The manual references an optional second SIM - there must be a variant out there with dual SIM support, however, mine only has a single slot. The phone also comes with a removable 1000 mAh battery, a mono wired headset, and a charger (unfortunately the cable is integrated into the wall power supply, so you will need your own microUSB cable to connect it to a PC).
My model is a "VFD 120" in the grey slate colour - note the single SIM slot labelled as "SIM 1".
Screenshot of the home screen:
Gaining ADB Access
As SP Flash Tool is unsigned software whose origin I am not sure of (supposedly MediaTek but the site appears unofficial), I used a Windows VM to perform the steps below. An easy way to set up a temporary one is to use the VM images Microsoft provides for Edge browser testing. If you want you can download one from here (https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/) and run it in your preferred virtualisation software. If you have trouble trying to get the VM to capture the USB device at the right time when plugging the phone in, you might need to just run it directly.
Download SP Flash Tool from here
Download the scatter file: (Updated link coming soon)
Download the modified boot image: (Updated link coming soon)
Open SP Flash Tool, select the "download" tab and select the scatter file as the "scatter-loading file". What this does is provide SP Flash Tool with the details about the partition table on the phone's flash memory.
Select the boot image file as the location of BOOTIMG by double clicking in the location cell of the BOOTIMG row. Ensure the dropdown is set to Download Only. Click the download button at the top.
With the phone powered off, plug it into the computer. Flashing should now begin. Once it is done, the phone should reboot - if not, perform a reboot manually by doing a reset.
If the phone didn't flash, you likely need to install drivers for the MediaTek preloader. There are web links for these within the Drivers folder of the SP Flash Tool folder - the VCOM driver is likely most relevant for this. After it's installed try again from step 5.
Access a shell on the phone through ADB by running
adb shellin a command line terminal.
Enter the command settings put global install_non_market_apps 1`. The phone will now allow you to install apps from APKs.
Many thanks to Kugelblitz from the Mobiwire Modding Discord server, who provided the scatter file and the modified boot image to get ADB working on the Sakari.