Hi, On a 486, I am booting linux 2.0.40 from a floppy but wonder if I have done something wrong in the building of the kernel image + bootloader:

zImage has been written to the disk.

I get the Loading...... (presubably from linux/boot/head.S"

Then the computer reboots itself straight after the last "." (i.e. I don't get the "Uncompressing Linux" message (from arch/i386/boot/compressed)

What could be the most likely reasons for the reboot?

I made the Kernel with

make menuconfig (choose some options....)
make dep ; make clean
make zdisk (kernel gets built then the floppy disk goes chug chug for a while)


Thanks in advance...

The output from the building of the kernel is:

tools/build bootsect setup compressed /vmlinux.out CURRENT > zImage
Root Device is (22,1)
Boot Sector is 512 bytes
Setup is 4380 bytes
System is 285 bytes
sync
Leaving .....arch/i386/boot

I used to be able to build bootable floppies without issue but something must have changed.....

Any help/pointer appreciated. I am guessing the issue is nothing to do with the kernel as such but something to do with the bootloader not being happy?

so is this computer also from the erly 1990's

the 2.0 kernel is 20 years old

ye it is an old 486. I needed to rebuild the kernel because of a change of network card.

Its 2.0.40 running on 486 building kernels and booting of floppies used to work fine on this machine - last build was done about 18 months ago.

I don't know all the caused of getting a reboot after "Loading.........." but before "Uncompressing Linux" that suggests that the bootloader has some problem?

My latest attempt is that I have grabbed an archive of the 2.0.20 kernel and created a bare minimum kernel and built a zImage and copied to a floppy. That still has the issue of the computer rebooting right before the "Uncompressing Linux" message. I blank the floppy first to made sure the image that I create is the image that is the one on the floppy.

I have now had the idea to copy vmlinux straight to the floppy....That will get round the need to uncompress the kernel.... I haven't had a chance to try that yet.

Any ideas still welcome.

Here is an update: The vmlinux idea didn't work as the machine started reading the disk and then just got stuck at a blank screen.

The last time I built a successful floppy was November 2015 which was kernel 2.0.40

I am guessing the issue must be some environmental wherby something goes wrong creating the zImage/vmlinux. If any old hands have any ideas that would be really helpful.

What I am going to try now is to build a zImage on a different system (build a kernel targeted at 486). That should be a way to create a successful bootable image.

Thanks for spending the time looking at this question.

How old is the floppy disk - maybe some bad sectors?