Trouble with booting to FreeDOS for IT crossflashing

[K1LLA_KING_KONG]

I'm attempting to crossflash my Dell PERC H310 adaptor following this guide https://fohdeesha.com/docs/perc.html

My mobo bios will not boot from USB FreeDOS image (made with Rufus) I tried iso and freedos boot selection

I am however able to boot into the cards bios

Which takes you into the config utility (not relevant but just thought I'd mention to show the cards details)

My mobo: Gigabyte GA-Z270X-Gaming K5 https://www.gigabyte.com/id/Motherboard/GA-Z270X-Gaming-K5-rev-10/sp#sp
Manual: https://download.gigabyte.com/FileList/Manual/mb_manual_ga-b250m-gaming3_e.pdf

Here's what I can boot (intel is my truenas boot drive)

According to the guide the following must be disabled in bios:

I have disabled VT-d (Virtualization)
However the other two I do not have options for: intergrated devices> I/OAT & SR-IOV

I have set both storage and PCI devices to bott with Legacy mode

How do I get this to boot?

 

[Ericloewe]

Does your motherboard's firmware even support booting into real mode binaries? Are you sure that the vestigial CSM bits aren't there just to support weird PCI devices with weirder option ROMs? CSM was supposed to disappear from Intel's base firmware package a few years ago, and I've been surprised on multiple occasions to see it hanging around.

Anyway, what CSM options do you have and are they set to "CSM" or "legacy" or "BIOS" or "Onion tied to the belt" or whatever makes you feel thirty years older?

If that's a dead end, it's also always a possibility that Rufus is doing stupid things instead of just copying stuff over. You might want to try a different tool (e.g. USB Image Tool).

 

[K1LLA_KING_KONG]

Does your motherboard's firmware even support booting into real mode binaries? Are you sure that the vestigial CSM bits aren't there just to support weird PCI devices with weirder option ROMs? CSM was supposed to disappear from Intel's base firmware package a few years ago, and I've been surprised on multiple occasions to see it hanging around.

Anyway, what CSM options do you have and are they set to "CSM" or "legacy" or "BIOS" or "Onion tied to the belt" or whatever makes you feel thirty years older?

If that's a dead end, it's also always a possibility that Rufus is doing stupid things instead of just copying stuff over. You might want to try a different tool (e.g. USB Image Tool).

So im testing this on 2 different mobos now. The Gigabyte mentioned above and my personal machine a MSI Z790 Tomohawk DDR5

It disables igpu function when you enable CSM, so iv added a gpu.

Now I have finally got into Freedos usb

And was able to erase the flash

Next step is to boot into Linux iso, something iv also never done before. Just waiting for the iso to download.

I hope this will boot

 

[K1LLA_KING_KONG]

Update: Successfully Crossflashed the H310 to IT mode

Testing a single HDD connected to card

Successfully detected in Truenas

(I'm a happy man)