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