Oh, wow, I totally missed that! Thank you!!! I wasted an entire day rummaging around and didn't manage to see that :)
Just in case others run across this:
You want 4SPI configuration, not IIC like I have in the pic.
The number of screens you have must match the configuration you set in the bootloader, otherwise you get noise, and won't be able to write to all the lines/columns
Also easy to miss, but for the 1306 RES connection, you need to wire it up like this (again, connections on your 1306 PCB): GND -> 10uf cap -> 1k resistor -> VCC. Once done, RES will be tied to where the cap and resistor meet (like this)
It wasn't clear to me how to actually use the bootloader for the STMF4 board, but it's essentially:
Plugin your board as you normally do
Open MIOS Studio
Click Browse and choose the mios32_bootloader app (download here)
Click Start. If it won't complete, try unpluging/pluging the board and trying again
Unplug/plugin the board
In the MIDI IN and MIDI OUT sections whatever app you had prior to all of this might be listed, but it doesn't actually exist (and it shouldn't). That's why you now see the error "No response...". The new app, MIOS32, took its place and you need to refresh to see it.
Click Application -> Rescan MIDI Devices
Click Understood in the pop-up (this will make your old app disappear, and the MIOS32 app show up)
Change MIDI IN and MIDI OUT to MIOS32
Enter these one by one into the input box: (send a command to MIOS32 application). Keep in mind lcd_num_x must match the number you have chained: set lcd_type GLCD_SSD1306
set lcd_num_x 1
set lcd_num_y 1
set lcd_width 128
set lcd_height 64
store
Yah. Bootloader is done. Time to restore your app in MIOS Studio:
Click Browse and choose whatever app you want, like midibox_ng
Click Start. Like the bootloader, if it won't complete, try unpluging/pluging the board and trying again
Unplug/plugin the board
Now for some test display data. Lets set some values for your SSD1306 OLED's in MIOS Studio:
Click on Tools -> MIOS32 File Browser
Click Create File
Create some name like LCD.NGC
Click Update
Click on the file you just created
Click Edit Text and add the following test example:
RESET_HW
LCD "%C"
LCD "@(1:1:1)A23456789012345678901234567890"
LCD "@(1:1:2)B23456789012345678901234567890"
LCD "@(1:1:3)C23456789012345678901234567890"
LCD "@(1:1:4)D23456789012345678901234567890"
LCD "@(1:1:5)E23456789012345678901234567890"
LCD "@(1:1:6)F23456789012345678901234567890"
LCD "@(1:1:7)G23456789012345678901234567890"
LCD "@(1:1:8)H23456789012345678901234567890"
Click Save
You should now have 8 rows and 21 columns of text. If you need to flip it 180 degrees, you can redo the steps above and add set lcd_type GLCD_SSD1306_ROTATED before you store.