linux_reboot_magic2

The linux_reboot_magic2 function is used to initiate a reboot on a Linux system. It is typically called by higher-level functions, such as sys_reboot, to perform the actual reboot.

Here is an explanation of each step involved in the linux_reboot_magic2 function:

  1. The function begins by checking if the magic number passed as an argument is equal to the predefined LINUX_REBOOT_MAGIC2 constant. This magic number is used to ensure that the system is not accidentally rebooted.

  2. If the magic number is not equal to the LINUX_REBOOT_MAGIC2 constant, the function returns an error code indicating that the reboot request is invalid.

  3. If the magic number is valid, the function proceeds to execute the reboot. The specific method of rebooting depends on the value of the second argument passed to the function.

  4. If the second argument is equal to the LINUX_REBOOT_CMD_RESTART constant, the function performs a full system restart. This is equivalent to pressing the reset button on a physical system.

  5. If the second argument is equal to the LINUX_REBOOT_CMD_HALT constant, the function halts the system. This is equivalent to turning off a physical system.

  6. If the second argument is equal to the LINUX_REBOOT_CMD_POWER_OFF constant, the function powers off the system. This is equivalent to unplugging a physical system.

  7. If none of the above conditions are met, the function returns an error code indicating an invalid reboot command.

  8. Once the reboot operation is executed, the function does not return. The system is either restarted, halted, or powered off, depending on the command specified.

It's important to note that the linux_reboot_magic2 function is a low-level function and should be used with caution. Rebooting a system without proper justification or understanding of the consequences can lead to data loss or other issues. It is recommended to consult system documentation and guidelines before using this function.