On Tue, 2 Jul 2013 11:29:47 +0000 (UTC) Duncan <1i5t5.dun...@cox.net> wrote:
> > > > First, there is a new kernel option called "Kernel support for scripts > > starting with #!." > > > And no, as you found out it's *NOT* initramfs-only. It's basic kernel > functionality that been assumed for (I guess) decades now. > > But as you may have noticed, openrc, gentoo's default init system, uses > #!/sbin/runscript to point to runscript (part of openrc), as its script > interpreter, and it may well be that turning off kernel shebang support > screwed you up that way. > I am entirely sure what is happening with this kernel "#!" option. My boot scripts are very simple and customized for my specific machine (as opposed to having a complex set of highly generalized scripts that attempt to account for every possible situation). Basically, once the kernel loads itself, it invokes the init binary which then uses parameters in /etc/inittab to invoke appropriate scripts (or other binaries). From my inittab, only a single bash script is called for system initialization and this bash script runs just fine _without_ the kernel "#!" option. However, after this bash initialization script executes, the console login process then begins. My inittab contains this line for login: agetty -n -l /sbin/autologin 38400 tty1 Now /sbin/autologin is another bash script and it is *only at this point* that the boot fails to complete without the kernel "#!" option. IOW, my bash boot scripts succeed but the bash autologin script fails w/o the kernel "#!" option. I suspect, although I have not tested it, that if I substitute a normal binary login (i.e. /bin/login) for the bash /sbin/autologin then the boot will be completely successful w/o the kernel "#!" option. So what does the "#!" option accomplish? Does it allow the kernel to effect redirection based on "#!?" This should only be necessary if bash itself is not invoked, but in boot-up based on init and inittab, bash, I believe, is automatically invoked for all scripts. But yet the agetty program, after boot-up is essentially complete, fails to execute the bash script in its parameter list. At this point is it agetty, or the kernel, that is responsible for executing the autologin script? I need to study this more. Frank Peters
