3 ms·

In that era, you could often just ensure that the BIOS could load the bootloader/kernel by placing it into the region still reachable by the BIOS. OSes like Lin

by anyfoo 8y ago

In that era, you could often just ensure that the BIOS could load the bootloader/kernel by placing it into the region still reachable by the BIOS. OSes like Linux (and anything Windows NT based) practically completely disabled[1] the BIOS anyway, and their own IDE drivers would be recent enough to understand how to address the full disk. It was not uncommon to have a small boot partition at the beginning of the disk for that purpose. [1] Bit of a simplification. In reality, the BIOS being 16bit real mode code meant that you had to jump through very elaborate hoops if you wanted to use it in your protected mode OS in any way, and then for questionable gain.

jchw 8y ago
Oh yeah, definitely. I could get it to boot by marking the disk as 8 GB in BIOS, but this had side effects: - I'm using CompactFlash as many do, since it's fast, cheap, and reliable. Some of my CF cards are smaller than 8 GB, and if I hard code it I can't boot with those. - I actually do run OSes on that machine that thunk out to BIOS (Win98 for example.) If I really wanted a computer for useful things, no doubt I'd run Linux on it, but all the same, I've got plenty of smaller computers with unilaterally more power (even a RPi is much faster.) (FWIW: autodetect properly detected the right parameters, it just locked up on boot. My guess is it was some kind of simple integer overflow bug or something.)
nisa 8y ago
> It was not uncommon to have a small boot partition at the beginning of the disk for that purpose. still had to that a few weeks ago because on a dell r720 grub did not want to boot my zfsonlinux rootfs on a 6tb pool - it's either the dell hba controller, grub oder some other limitation but once you go beyond 2tb or 4tb disk I always run into strange behavoir. Maybe UEFI solves that, I don't know.
- jchw 8y ago
  EFI doesn't solve it directly, but GPT does. Regular MBR can't handle more than 2tb disks. Of course when running EFI you always want to use GPT. Linux might be able to handle >2tb MBR somehow, but in doing so it might be confusing your BIOS perhaps.

by anyfoo 8y ago

jchw 8y ago

Oh yeah, definitely. I could get it to boot by marking the disk as 8 GB in BIOS, but this had side effects: - I'm using CompactFlash as many do, since it's fast, cheap, and reliable. Some of my CF cards are smaller than 8 GB, and if I hard code it I can't boot with those. - I actually do run OSes on that machine that thunk out to BIOS (Win98 for example.) If I really wanted a computer for useful things, no doubt I'd run Linux on it, but all the same, I've got plenty of smaller computers with unilaterally more power (even a RPi is much faster.) (FWIW: autodetect properly detected the right parameters, it just locked up on boot. My guess is it was some kind of simple integer overflow bug or something.)

nisa 8y ago

> It was not uncommon to have a small boot partition at the beginning of the disk for that purpose. still had to that a few weeks ago because on a dell r720 grub did not want to boot my zfsonlinux rootfs on a 6tb pool - it's either the dell hba controller, grub oder some other limitation but once you go beyond 2tb or 4tb disk I always run into strange behavoir. Maybe UEFI solves that, I don't know.

jchw 8y ago
EFI doesn't solve it directly, but GPT does. Regular MBR can't handle more than 2tb disks. Of course when running EFI you always want to use GPT. Linux might be able to handle >2tb MBR somehow, but in doing so it might be confusing your BIOS perhaps.