Re: GRUB reboots system after loading kernel and initrd on 80486

[Andrei Borzenkov]

07.11.2016 16:49, tedheadster пишет:
> GRUB developers,
>   I just installed GRUB 2.02~beta2-22+deb8u1 from the current Debian

Please retest with current git head.

> distribution. I am using it to boot an _old_ 80486 (squeeze)
> distribution on a second partition.
> 
> Legacy GRUB can load the old squeeze just fine. Current GRUB reboots
> the computer after attempting to boot the kernel.
> 

Did you test linux16 loader? That is what legacy grub effectively uses.

> I did a 'set debug=all' right before the 'linux' and 'initrd'
> commands. Below is the output.
> 
> - Matthew
> 
...

> loader/i386/linux.c:601: real_mode_mem = 0x40ed220
> loader/i386/linux.c:611: code32_start = 1000000

at this point we are about to jump to loaded kernel

> lib/relocator.c:1385: chunks = 0x3fe3eb0
> lib/relocator.c:434: trying to allocate in 0x1000-0xffffff2f aligned 0x10 size
> 0xd0
> lib/relocator.c:1186: allocated: 0x982000+0xd0
> lib/relocator.c:1397: allocated 0x982000/0x982000
> lib/relocator.c:1398: chunks = 0x3fe3eb0
> lib/relocator.c:1521: Preparing relocs (size=61)
> lib/relocator.c:434: trying to allocate in 0x0-0xffffffc3 aligned 0x1 size
> 0x3d
> lib/relocator.c:1186: allocated: 0x9820d0+0x3d
> lib/relocator.c:1533: Relocs allocated at 0x9820d0
> lib/relocator.c:1548: chunk 0x982000->0x982000, 0xd0
> lib/relocator.c:1548: chunk 0x40ed220->0x8b000, 0x5000
> lib/relocator.c:1548: chunk 0x37a7000->0x37a7000, 0x28dfc0
> lib/relocator.c:1548: chunk 0x100000->0x1000000, 0x882000
> lib/relocator.c:1592: sorted chunk 0x100000->0x1000000, 0x882000
> lib/relocator.c:1592: sorted chunk 0x982000->0x982000, 0xd0
> lib/relocator.c:1592: sorted chunk 0x37a7000->0x37a7000, 0x28dfc0
> lib/relocator.c:1592: sorted chunk 0x40ed220->0x8b000, 0x5000
> (system reboots at this point)
> 

Please add grub_dprintf to grub_relocator32_boot to see how far it
proceeds.