There is no universal solution to this. Some vendors support fwupd (LVFS) on some hardware (Dell, Lenovo), some allow to update via a file on a USB stick (Asus).

Unless it is a system from Linux first company (Tuxedo, StarLabs, System76, Slimbook) expect to manually check what the specific model you are looking at supports.

I had an Acer laptop once. I had Ubuntu on it. I had problems with random crashing after a few minutes, I ran memtest, it took a few hours for a full test and came back with a whole slew of faults. I sent it to Acer under warranty and they told me that Linux was the problem and I should leave windows on it.

Install windows on a second/spare drive. Boot PC from this and run their tool.

I know you're trying to find a way around not using windows, but if the vendors only solution involves it, I wouldn't trust any hacky workarounds when it comes to bios updates.

And this is one more reason I will only buy a laptop from System76, Framework, or Tuxedo to run Linux.

All motherboard manufacturers irrespective of OEM should provider a firmware mode that can be boot to, allowing BIOS upgrades. But since they don’t seem to, especially with laptops, seems best to stick with known vendors whose primary OS they support is Linux.

Good luck, OP. Hope the live Windows USB thing works. Just be careful to not get infected with Recall or any other Microsoft nonsense :)

Is there an option to save the new bios update file to a USB stick, then enter bios and trigger an update manually that fetches the file from said USB stick?

I've done it this way with an Asrock motherboard for desktop running Bazzite.

All the security updates are in the microcode loaded by the bootloader even before the kernel is loaded, so unless there's some new feature, bugfix, or hardware support you specifically know you need it's not important to update your BIOS anyway. Which is good, because as far as I can tell you're just screwed by a bad hardware vendor.

if the provide and exe, You can always create a bootable usb stick of freedos or another dos tool. Copy the file onto the stick. boot to it and cd to where the file is and issue filename.exe

Depends on the exact model. The usual way on Linux is via fwupdmgr.

Frankly in my opinion, bios should only be updatable from the bios itself. No matter which os we talk about, it can always get in the way.

Acer has had this policy for over 20 years. I bought a laptop long ago from a vendor that I had issues with and they refused to give me support because I was running Linux at the time. (I forget what distro. Probably either Mandrake or early Ubuntu.) That laptop went right back to the vendor.

Never bought anything from them since.

Acer supports 2 of their devices on Linux

https://fwupd.org/lvfs/devices/

I feel your pain. I've searched a bit online and found several different methods (not for Acer though) that all go way over my head. I just leave the BIOS to deprecate on its own by now.

I know for HP machines, the bios updater exe can be decompressed and you can just get the bios image and the signature file from that.

Idk what machine you have, but at least for an older aspire laptop my friend has, there is a bios download.

If you follow instructions to make bios recovery media, you can update your bios through that.

Edit: that Acer laptop you have doesn't even show up on Acer's support page. Supposedly it's sold as an Acer aspire a something or other. If you search based on your snid, you should be able to get to a downloads page.

Also clevo seems to make this laptop, according to the Acer India webpage I found for it

Usually you can extract the windows updater exe and use the bios/bin/upd file via mainboard bios update mechanisms

Sorry, but in your case the only way is to install Windows. Make a dual boot.

I know some BIOS update that works with FreeDOS.

Just basically need to flash it into a USB drive and run the BIOS update .exe with it.