I see. So the third stage bootloader loads the kernel into memory, as well as the boot_archive, informs the kernel where the archive is (in memory), then the kernel uses the drivers and such in the programs to load the root and execute /sbin/init?
I checked the filelist document in https://github.com/illumos/illumos-gate/blob/master/usr/src/cmd/boot/filelist/i386/filelist.ramdisk and didn't see an /init, do does that mean that whatever the kernel does at that time is completely controlled by the drivers (as I would expect)? If so, then could it be as simple as sliding an /init into the boot_archive and then avoid mounting any disk filesystems? On Fri, Jul 26, 2024, 12:58 PM Bill Sommerfeld via illumos-discuss < discuss@lists.illumos.org> wrote: > On 7/26/24 07:14, Bryce wrote: > > I tried some googling but I couldn't find out what's usually in > > `boot_archive', nor could I find anything in illumos-gate relating to a > > default, nor in oi-userland. Is boot_archive generated per distro or is > > it in illumos-gate? > > The boot archive is generated by 'bootadm update-archive', which can be > run manually by the administrator but it generally gets run > automatically when needed at reboot time and by the > svc:/system/boot-archive-update SMF service (which runs at boot once the > relevant filesystems are mounted read-write). > > Under the covers, 'bootadm update-archive' runs the > /boot/solaris/bin/extract_boot_filelist script to enumerate the files > and directories from the real root that should be included in the > archive. Note that if a directory is named, the entire tree rooted at > that directory is included. > > As others have mentioned, SmartOS does things somewhat differently but > the above applies to most general-purpose illumos distributions. > > > I read the bootadm(8) man page hoping for some answers but none came. > > Although it did mention the available archive formats, does that mean > > that boot_archive is archived into an (eg cpio) archive, and then > > mounted RO by the kernel so it can load the modules necessary to talk to > > the hardware? > > Yes. > ------------------------------------------ illumos: illumos-discuss Permalink: https://illumos.topicbox.com/groups/discuss/Tc9bfa679c7294ee7-M96a23a88deac9c4b51094660 Delivery options: https://illumos.topicbox.com/groups/discuss/subscription
