On Fri, Jan 01, 2016 at 06:32:34PM +0000, Rainer Weikusat wrote: > John Rigg <d...@jrigg.co.uk> writes: > > On Fri, Jan 01, 2016 at 12:26:41PM -0500, Steve Litt wrote: > >> If / is formatted ext4, it can be mounted directly by a kernel with ext4 > >> drivers, no initramfs needed. > > > > Wasn't the original reason for having an initrd that the boot loader, > > probably LILO at the time, couldn't handle a kernel image above a > > certain size? (My recollection could be faulty here, so corrections > > welcome). > > Oh wow. That got twisted :-). LILO loads a kernel image via BIOS calls > and "10,000 years ago" (ie, I've encountered this problem once, on my > very first Linux install, RH3.0.3, and then "nevermore" despite I've > been using LILO all the time), the BIOS couldn't load anything beyond > "the 1024 cylinder boundary" (504M). Hence, a kernel supposed to be > loaded by LILO had to be located in the first 504M of a disk. This > becomes a problem when dual-booting similarly ancient "other PC OSes" > (in my case, OS/2 Warp 4) which insist on residing on the first primary > partition.
The 1024 cylinder boundary was why a separate /boot partition at the start of the disc became common, but still doesn't explain why an initrd.img became necessary. I used to know this stuff but it was a long time ago :-) John _______________________________________________ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
