FreeDOS boot hangs at "Loading FreeDOS 123" on Intel Atom Z3735F (Bay Trail) device with ia32 UEFI

[volkertb]

The Intel Atom Z3735F ("Bay Trail") SoC, which shipped a decade ago on a number of low-power and budget devices, such as the Intel Compute Stick and a number of tablets, is notorious for having an ia32 UEFI, even though the CPU is perfectly capable of running 64-bit software. It also didn't come with a CSM, so out of the box, it usually only shipped with the 32-bit editions of Windows 8, Windows 10, or Ubuntu Linux.

Later versions of the most common 64-bit Linux distros (Ubuntu, Fedora, Arch Linux) later gained the ability to boot and run on these devices through some kind of shim/thunking solution, even though the UEFI was 32-bit.

It was still not possible to boot 64-bit versions of Windows 10, or (pre-UEFI) Windows versions older than Windows 8.

With the IA-32 build of CSMWrap, however, this should now be possible. (Thanks again for making this!)

So I tried CSMWrap 1.2.1 (ia32) on my Bay Trail device. The good news is that it successfully loaded SeaBIOS, it accepted input from the USB keyboard that I had attached to it, and it appeared to support booting either from the integrated eMMC drive or from a USB drive.

The bad news is that FreeDOS appears to hang on boot, at the message Loading FreeDOS 123.

Pressing CTRL-ALT-DEL did not help. The system appeared to be completely locked up at this point. I've tried booting it more than once, but I never got past the Loading FreeDOS 123 message.

I did some googling for this message, to see whether this was a common problem separately from the whole UEFI/CSM thing, but I couldn't find anything after a few minutes of searching.

The FreeDOS image that I tried was the FullUSB IMG file of FreeDOS 1.4, extracted from FD14-FullUSB.zip, and written to an SD card with the dd command-line tool. I had that SD card plugged into a USB SD card reader, which I had plugged in to the device through a USB hub, since SeaBIOS unfortunately did not detect the SD card when I had it inserted in the integrated SD card slot of the device.

Below I'm attaching a video of the failed boot attempt. You can see that I have also installed the rEFInd boot manager on the device, which appears to launch CSMWrap just fine.

It from what I briefly saw from the output while loading SeaBIOS, CSMWrap was unable to locate a legacy VGA Option ROM on this device, and so fell back to the SeaBIOS fallback VGA ROM. I hope to find a compatible ROM that adds actual native legacy VGA compatibility to this device, but I don't think this SoC ever shipped with a CSM in any device.

But it would be nice if we can get FreeDOS to at least boot in text mode.

Thanks for your continued work on this amazing project!

2025-05-30_freedos_hangs_on_bay_trail_with_csmwrap.mp4

[FlyGoat]

I would suspect it's something related to SD Card, can you try a proper USB flash disk?

I see a somewhat related post:
https://www.vogons.org/viewtopic.php?t=53743

I recall baytrail lacks some legacy IO port support, maybe that's the problem. Can you try other OS? e.g. Modern Windows/Linux.

Thanks

[Gelip]

To volkertb
Wow. If you want you can test my WinXP 32-bit tutorial - I added eMMC drivers:
https://forums.mydigitallife.net/threads/winxp-32-bit-on-a-modern-pc-iso-boot-wim-install-wim.88834/
https://forums.mydigitallife.net/threads/winxp-32-bit-on-a-modern-pc-iso-boot-wim-install-wim.88834/#post-1873965

I found VBIOS for BayTrail:
#37 (comment)

[volkertb]

@Gelip Thanks for sharing. I'll go into that further in that thread. 👍🏽

[volkertb]

I would suspect it's something related to SD Card, can you try a proper USB flash disk?

I just tried it with a USB stick (not an SD card), containing a bootable FreeDOS 1.3 image (one release earlier than the FreeDOS 1.4 image on the SD card that failed earlier). The result is unfortunately very similar:

I recall baytrail lacks some legacy IO port support, maybe that's the problem. Can you try other OS? e.g. Modern Windows/Linux.

First I'll try some other DOS variants (SvarDOS and MS-DOS), to see what result I get with those. I'll try some older Windows versions after that.

I'll also try CloverBootloader, as a way to get a 64-bit UEFI working on this device. (32-bit native UEFI -> CSMWrap -> Clover 64-bit UEFI)

I'll let you know what my results are.

[Gelip]

volkertb - why do you need UEFI 64-bit?
UEFI32 > CSMWrap > UEFI64 > CSMWrap > FreeDOS ????? This is stupid and that's probably why FreeDOS isn't working for you.

Try like this:
UEFI32 > CSMWrap32 > FreeDOS

[FlyGoat]

Yes, this is likely irrelevant to EFI bitness.

I'd recommend trying a modern OS to get some debug information.

[volkertb]

@Gelip My proposed Clover trick is not for booting DOS. It's for booting the 64-bit version of Windows 10 on Bay Trail devices with a 32-bit UEFI. Clover is indeed not needed for FreeDOS, or any DOS for that matter. Sorry if I caused any confusion there.

[volkertb]

@FlyGoat I ultimately managed to boot SvarDOS successfully. However, the boot process is quite unstable, regularly hanging in different phases of the boot process or while loading the DOS kernel, sometimes not detecting the USB device, or suddenly automatically rebooting while loading the DOS kernel. Also, the fact that I had two (quite populated) USB hubs daisy-chained to the Bay Trail device didn't help. After I had plugged in just one USB hub with only a USB keyboard and the populated USB SD card reader, it would work about one out of 10 times or so. Also, the device would sometimes hang before it even loaded the rEFInd boot manager that I installed on it, which should have nothing to do with CSMWrap.

But, 1 out of x times it does work, so that in and of itself is already impressive. Good work! 😃

As you can see from the video, screen updates during scrolling are very slow. Of course it has to constantly redraw all the characters to the GOP framebuffer in software. Also, when I ran the SvarDOS installer, it just showed an empty blue screen. Pressing the Escape key brought me back to the command prompt.

My guess it that this device would boot more reliably if the bootable DOS partition were installed on the integrated eMMC as opposed to a USB drive. But it will take me some more work to set that up.

SvarDOS_build_20240915_working_on_bay_trail_with_csmwrap.mp4

[Gelip]

volkertb - try this Win10:
https://windowsxlite.com/Micro10_x86_SE/

[volkertb]

OK, so I hooked up a USB Blu-ray drive through the USB hub, and it gets detected on each start, without any weird hangs before getting into the rEFInd menu. Also SeaBIOS appears to detect it on each boot. This is unlike the flaky behavior that I experienced with the USB flash drive and the populated USB SD card reader, that I'd been trying before.

I tried booting the installers of multiple operating systems on optical media.

Here are my findings.

• Windows XP x64 Edition: within seconds when the CD starts booting after selecting the optical drive in the SeaBIOS boot menu, the screen goes black and the system is unresponsive.

• OpenSuse 11.3 (an OS installation CD-ROM I got with a magazine in 2010): It boots into the boot menu of the installation CD, but it does show the message graphics initialization failed. Apparently, it tried to show a graphical boot menu with a splash screen. The boot menu shown is apparently some text mode fallback menu. I can enter any of the boot options at the boot : prompt, but none of them work and result in a hanging system. In the case of booting the live system, I get a black screen, as I did when I tried to boot the Windows XP x64 Edition installation disc. Ditto when I enter mediacheck. When I enter memtest, part of the screen goes black, some text on the side of the screen is still visible, but the system hangs at that point.

  

• Windows 8 64-bit installation disc: shows the blue Windows 8 logo for a while, and then shows an error message with a blue background. It offers me a menu, but none of the options that I try selecting get me any further than the error.

  

  

  

The error code displayed, 0xc0000225, apparently means that it couldn't find certain boot/system files, or that they are corrupted. The installation disc looked fine, and I've rarely used it.

• Windows 8 32-bit installation disc: as expected, this CD also shows up as a boot option in rEFInd, since it's actually designed to natively boot from 32-bit UEFI systems. And booting it that way, the installer comes up fine. But when booting it through CSMWrap, I initially get the same (off-center) boot logo as I did with the 64-bit disc, followed by another error message, this time without a blue background or any possible menu options to select. It specifically shows error code 0X0000005C, which apparently means HAL initialization failed and apparently is something driver-related, or a problem with expecting certain subsystems (APIC). At least, that's what a quick Google search yielded me.

  

  

It would seem that Windows XP x64 Edition and OpenSuse 11.3 are so old that they simply won't work if there is no actual legacy VGA compatibility, whereas Windows 8 was new enough that it accessed graphics through VBE, so it would work with the GOP framebuffer. But apparently there are still some other things missing (or different) that both the 64-bit and 32-bit variants of Windows 8 are unhappy with for some reason.

I hope this is useful!

[volkertb]

By the way, sorry for the dust particles on the monitor in those pictures. I really should clean it. 😅

[win98se]

For Windows 8.1 x86, I have the exact same 0x0000005C error (even parameters are exact same) after DISM applying install.wim to the internal storage. However, my device (Asus Transformer Pad TF103C) has a Z3745 instead (it has a 64-bit UEFI without any Legacy booting option).

P/S: Installing Windows 8.1 x64 by native UEFI works, but it doesn't have any usable driver.

[Gelip]

@volkertb
I compile CSMWrap replacing SeaVGABIOS to ValleyView Legacy video BIOS but risky to use because it can reportedly damage the screen.