SOLVED: In rEFInd, need 2 different OS icons for 2 instances of same OS (Ubuntu-MATE)

SOLVED: See bottom of this post.

I have an Ubuntu-MATE 20.04 LTS install (kernel 5.11.0) on an internal nvme0 drive.

SOLVED: See bottom of this post.

I have another MATE 20.04 install (kernel 5.4.0) on an internal SSD (2.5-inch), as a backup OS to the main 20.04 that's on the nvme0 drive.

In the GUI boot-manager program known as rEFInd (version 0.13.2, the current version), I've put into rEFInd's "myicons" directory the green-circle MATE icon, and named it "os_ubuntu.png", to match and replace the vanilla-Ubuntu red-circle icon that has that same name ("os_ubuntu.png") and which is in rEFInd's "icons" directory, per the advice of the "Setting OS Icons" section of the rEFInd website.

At the moment (while I'm still in the process of setting up rEFInd) I have just two visible OS icon "tags" (as they are called in rEFInd) showing on the rEFInd menu, one for each of the two MATE installs. (For now, I've set to "hidden" a mess of other OS tags that I'll need to sort through later.)

My problem is that those two icon-tags have the same icon, and I'd like to have a different icon representing the install on the SSD, to easily and visually distinguish between the two OS instances, even though they're the same OS.

As per the first bullleted paragraph on the rEFInd website under "Setting OS Icons", on the page about configuring rEFInd, I did the following:

(1) I tried putting the second icon inside of the "myicons" directory by naming the icon file "vmlinuz-5-4-0.png".

(2) tried naming it with the full name of "vmlinuz-5.4.0-7642-generic.png".

(3) I tried naming it "os_linux.png" to see if it would perhaps replace the "tux" icon of that name that's in the "icons" directory.

I did this making sure that the "scan_all_linux_kernels" option in the refind.conf file is set to (its default) "true".

The "Boot" line of text under the 2 OS icons in my refind menu reads, respectively:

"Boot EFI\ubuntu\grubx64.efi from NVME0_ESP"

and:

"Boot EFI\ubuntu\grubx64.efi from SSD_ESP"

since I named (using Gparted) the ESP file-system labels, respectively, "NVME0_ESP" and "SSD_ESP" to help distinguish between the two OS's.

However, I still get two instances of just the one icon for both OS's -- the "os_ubuntu.png" green MATE icon.

(The 2nd icon I'm trying to use is similar to that one, but has the letters "MATE" as part of the icon.)

As far as I can tell, according to the instructions under "Setting OS Icons", this should work.

Secure Boot is not active.

My Question is:

What do I need to do to show two different icons in the rEFInd menu to distinguish between two Unbuntu-MATE OS's that have the same name and same version number?

(P.S.: Before anyone tells me to put this question on the rEFInd forum, I've already done that.)

SOLVED: I was close with number (3) above.

I just needed to create a folder called linux

-- and then put a bootloader file in that folder (I copied the grubx64.efi bootloader file from the ubuntu dir) --

to be able to put an os_linux.png file in the /boot/efi/EFI/refind/myicons folder, and have that image file show in the rEFInd menu.

Solution 1:

SOLVED: I was close with number (3) above.

I just needed to create a folder called linux

-- and then put a bootloader file in that folder (I copied the grubx64.efi bootloader file from the ubuntu dir) --

to be able to put an os_linux.png file in the /boot/efi/EFI/refind/myicons folder, and have that image file show in the rEFInd menu.