Install failed with "FAILED TO LOAD COMMAND.COM"

[iyzsong]

Hello, with svardos-usb.img I can't finish the installation, both on a real hardware and qemu. qemu steps and log are:

wget http://svardos.org/download/20240201/svardos-20240201-usb.zip
unzip svardos-20240201-usb.zip
fallocate -l 1G disk.img

# Then run the installer in qemu
qemu-system-i386 -accel kvm -hda svardos-usb.img -hdb disk.img
# Results:
Format drive D:
Install SvarDOS
Your computer will reboot now.

# Then run qemu with only disk.img
qemu-system-i386 -accel kvm -hda disk.img

# Results:
INSTALLING SVARDOS BUILD SVARDOS
C:\COMMAND.COM > C:\CMD.COM
1 file(s) copied
 appinfo\amb.lsm -> C:\SVARDOS\appinfo\amb.lsm
 doc\amb\amb.txt -> C:\SVARDOS\doc\amb\
 bin\amb.com -> C:\SVARDOS\
Package amb installed: 3 files extracted, 0 errors.
ERR 2, FAILED TO LOAD COMMAND.COM

[bttrx]

This problem is caused by POSTINST.BAT making the COMSPEC environment variable point to the wrong drive.

You installed SvarDOS to drive D:, which is no longer present on the -hda disk.img run.

A workaround:

1. When SVARDOS INSTALLATION displays "Please remove the installation disk from your drive.", don't remove the "disk" (svardos-usb.img), but press any key to reboot.
2. On the "Welcome to SvarDOS" screen press ESC to quit the installer.
3. Run C:\SVED.COM C:\TEMP\POSTINST.BAT and in line 4 turn D: into C:
4. Leave SVED
5. Turn the machine off
6. Run qemu-system-i386 -accel kvm -hda disk.img

[bttrx]

@mateuszviste

Offending line in install.c is fprintf(fd, "SET COMSPEC=%c:\\CMD.COM\r\n", targetdrv);

Does it make sense to support other drives than C: here? C: is a hard-coded value at several other places, e.g., when creating PKG.CFG.

[mateuszviste]

Hi Iyzons, thanks for your very detailed report!

And thank you Robert for your investigations. I think you are right and the problem comes from the line you mention. I suppose that last time I tested USB installation it was on FreeCOM, and with it changing COMSPEC does no immediate harm as it is kept loaded in memory all the time.

Having targetdrv there makes no sense indeed, it's clearly a bug. After files are copied to the target drive and the computer is rebooted, the system drive is necessarily C:.

[mateuszviste]

I have committed the fix as suggested by Robert.

New ("bleeding edge") build 20240414 available on svardos.org. I hope it works. :-)

[bttrx]

Build 20240414 worked for me. :-)

[mateuszviste]

Build 20240414 worked for me. :-)

Awesome, thanks for testing! I'm closing the ticket then.

@iyzsong - hopefully it will work for you as well, but of course feel free to reopen the ticket if that's not the case. :)

[iyzsong]

Yes, it works for me too, on a VIA eden box, thanks!

[bttrx]

@iyzsong Thanks for your feedback!