Which sequence correctly describes a modern Linux boot from the moment the firmware hands control to the boot loader?
LPIC-1 Exam 101-500, objective 101. System architecture medium
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How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct Boot loader loads the kernel and the initramfs into memory; the kernel starts and uses the initramfs as a temporary root; the real root filesystem is mounted; PID 1 is executed
Correct. The boot loader's last act is to load both images and jump into the kernel, and the initramfs exists solely to bridge the gap until the real root can be mounted.
Not correct Boot loader loads the kernel; the kernel mounts the real root filesystem; the initramfs is then loaded from that filesystem; PID 1 is executed
Wrong, and self-defeating. If the initramfs had to be read from the real root, it could not be what makes the real root reachable.
Not correct Boot loader executes PID 1, which loads the kernel and then mounts the root filesystem
Wrong. PID 1 is an ordinary userspace program; only a running kernel can execute it, so it cannot precede the kernel.
Not correct The kernel loads the boot loader from the initramfs, mounts the root filesystem and then starts PID 1
Wrong, and inverted. The boot loader runs before the kernel and has finished its work by the time the kernel is executing.
Why
Each stage exists to make the next one possible: firmware finds a loader, the loader loads a kernel plus an initramfs, the kernel unpacks the initramfs into a memory-based root and runs its /init there as PID 1, that early userspace assembles and mounts the real root, and it then switches over and replaces itself with the system's real init program, which carries on as PID 1. Knowing the order is what lets a failure be placed: a firmware or loader problem never reaches a kernel message, a message-producing failure that ends in an emergency shell is an initramfs or root-device problem, and a failure after the real init starts belongs to the init system.
Where this comes from
- Cited
- manual page boot(7)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 101 and space the ones you get wrong.
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