Question: I have an issue installing Ubuntu 20.04 on my Dell XPS 15 9550.

Here are my actions:

1. Created a boot drive using Rufus in MBR mode
2. Disabled Intel Rapid Storage controller
3. Chose my USB stick from UEFI boot section
4. After GRUB had a black screen
5. Attempted to fix the issue by changing quiet splash to nomodeset (didn't work)
6. Attempted to boot from legacy boot section (got me into the live image)
7. Upon trying to install Ubuntu Windows 10 was not detected (theory: Ubuntu can't see Windows as the live image was launched in legacy mode)
8. Attempted to partition the drive manually and install Ubuntu that way, however GRUB failed to install to its partition
9. Formated the USB drive from Windows using Rufus again, but this time using GPT partition scheme
10. The drive wasn't detected as a bootable device

At this point I am not sure what to do. I'm guessing that I need to change some of my BIOS settings, but I don't know to what.

The strange thing is that I managed to install Fedora dual boot previously on this machine, but after removing it I wasn't able to install Ubuntu. (I removed both the partition and the GRUB bootloader to get a clean start)

Any advice will be welcome!

edit 1:
So added another EFI boot option by using the BOOTX64.EFI file in my BIOS however, I am met with a black screen after GRUB. I tried nomodeset again but that did not help.

Answer: 
you probably cannot select the sd card as a boot medium (like usb,cd or lan) in your bios.
if not available for boot i don't think you can use it for an os.

you might stick the sd card in a usb card reader and see if a default dual boot install or boot-repair will work.
First of all, thank you for your suggestions!
I found a solution:

I followed (mostly) this [guide](https://blog.hackdesk.com/running-ubuntu-on-micro-sd-card-on-surface-pro-4-dfe9e38e17e1). I changed:

* Step 21: I've chosen "erase disk and install ubuntu"
* Step 22&23: Choose the SD-Card
* before Step 28: check the names of your drives with "sudo fdisk -l" (see Zhihao Wu's [Comment](https://medium.com/@zhihaowu208/thank-you-for-writing-this-comprehensive-tutorial-6588e4e0cdf))
* Step 30: Don't drag "ubuntu" to the top (See MegaKyurem's [comment](https://www.reddit.com/r/SurfaceLinux/comments/9lrf6e/how_do_i_dual_boot_from_a_micro_sd_card_on_a/)). My Boot-order is: **USB** - Ubuntu - Windows

Reboot and it should work!
You can even turn "secure boot" in UEFI back on (if you don't want the read lock to appear on your boot-screen).