On Fri, 30 Nov 2007, Mikkel L. Ellertson wrote: > Robert P. J. Day wrote: > > i'm sure i'm going to regret asking this only seconds after i > > hit ENTER, but at what point during the boot process does the > > kernel's corresponding /boot/initrd.img file kick in and get used? > > > > i'm following along reading the logic of initramfs and early > > userspace, and can see where a compressed cpio archive can be > > incorporated into the kernel image itself. fair enough. > > > > but how does the /boot/initrd.img (which is itself a compressed > > cpio image) get processed during boot? it's certainly not passed > > as an argument to the kernel as i can see via /proc/cmdline. so > > how does it affect the boot sequence? thanks. > I believe that Grub loads the image, and then passes the location to > the kernel at boot. Support for the file system of initrd.img has to > be built into the kernel. but *how* does grub pass that info? that's the question here. on my f8 system, the contents of /proc/cmdline is simply: ro root=/dev/f8/root rhgb quiet so how exactly is the kernel notified about the location of that external initrd.img file? i'm guessing i might just start reading through the early kernel code to see where it figures that out. rday p.s. is my question making any sense? maybe i'm just phrasing it badly. ======================================================================== Robert P. J. Day Linux Consulting, Training and Annoying Kernel Pedantry Waterloo, Ontario, CANADA http://crashcourse.ca ========================================================================
